<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Memantine and can you explain it in depth? [/INST] Memantine is a medication used to slow the progression of moderate-to-severe Alzheimers disease. It is taken by mouth.Common side effects include headache, constipation, sleepiness, and dizziness. Severe side effects may include blood clots, psychosis, and heart failure. It is believed to work by blocking NMDA receptors.Memantine was approved for medical use in the United States in 2003. It is available as a generic medication. In 2019, it was the 169th most commonly prescribed medication in the United States, with more than 3 million prescriptions.

Medical use
Alzheimers disease and dementia
Memantine is used to treat moderate-to-severe Alzheimers disease, especially for people who are intolerant of or have a contraindication to AChE (acetylcholinesterase) inhibitors. One guideline recommends memantine or an AChE inhibitor be considered in people in the early-to-mid stage of dementia.Memantine has been associated with a modest improvement; with small positive effects on cognition, mood, behavior, and the ability to perform daily activities in moderate-to-severe Alzheimers disease. There does not appear to be any benefit in mild disease.Memantine when added to donepezil in those with moderate-to-severe dementia resulted in "limited improvements" in a 2017 review. The UK National Institute of Clinical Excellence (NICE) issued guidance in 2018 recommending consideration of the combination of memantine with donepezil in those with moderate-to-severe dementia.

Psychiatry
Bipolar disorder
Memantine has been investigated as a possible augmentation strategy for depression in bipolar disorder but meta-analytic evidence does not support its clinical utility.

Autism
Effects in autism are unclear.

Adverse effects
Memantine is, in general, well tolerated. Common adverse drug reactions (≥1% of people) include confusion, dizziness, drowsiness, headache, insomnia, agitation, and/or hallucinations. Less common adverse effects include vomiting, anxiety, hypertonia, cystitis, and increased libido.Like many other NMDA antagonists, memantine behaves as a dissociative anesthetic at supratherapeutic doses. Despite isolated reports, recreational use of memantine is rare due to the drugs long duration and limited availability. Also memantine seems to lack effects such as euphoria or hallucinations.Memantine appears to be generally well tolerated by children with autism spectrum disorder.

Pharmacology
Glutamate
A dysfunction of glutamatergic neurotransmission, manifested as neuronal excitotoxicity, is hypothesized to be involved in the etiology of Alzheimers disease. Targeting the glutamatergic system, specifically NMDA receptors, offers a novel approach to treatment in view of the limited efficacy of existing drugs targeting the cholinergic system.Memantine is a low-affinity voltage-dependent uncompetitive antagonist at glutamatergic NMDA receptors. By binding to the NMDA receptor with a higher affinity than Mg2+ ions, memantine is able to inhibit the prolonged influx of Ca2+ ions, particularly from extrasynaptic receptors, which forms the basis of neuronal excitotoxicity. The low affinity, uncompetitive nature, and rapid off-rate kinetics of memantine at the level of the NMDA receptor-channel, however, preserves the function of the receptor at synapses, as it can still be activated by physiological release of glutamate following depolarization of the postsynaptic neuron. The interaction of memantine with NMDA receptors plays a major role in the symptomatic improvement that the drug produces in Alzheimers disease. However, there is no evidence as yet that the ability of memantine to protect against extrasynaptic NMDA receptor-mediated excitotoxicity has a disease-modifying effect in Alzheimers, although this has been suggested in animal models.Memantines antagonism on NMDA receptors has aroused interest in repurposing it for mental illnesses such as bipolar disorder, considering the involvement of the glutamatergic system in the pathophysiology of mood disorders.

Serotonin
Memantine acts as a non-competitive antagonist at the 5-HT3 receptor, with a potency similar to that for the NMDA receptor. Many 5-HT3 antagonists function as antiemetics, however the clinical significance of this serotonergic activity in the treatment of Alzheimers disease is unknown.

Cholinergic
Memantine acts as a non-competitive antagonist at different neuronal nicotinic acetylcholine receptors (nAChRs) at potencies possibly similar to the NMDA and 5-HT3 receptors, but this is difficult to ascertain with accuracy because of the rapid desensitization of nAChR responses in these experiments. It can be noted that memantine is an antagonist at Alpha-7 nAChR, which may contribute to initial worsening of cognitive function during early memantine treatment. Alpha-7 nAChR upregulates quickly in response to antagonism, which could explain the cognitive-enhancing effects of chronic memantine treatment. It has been shown that the number of nicotinic receptors in the brain are reduced in Alzheimers disease, even in the absence of a general decrease in the number of neurons, and nicotinic receptor agonists are viewed as interesting targets for anti-Alzheimer drugs.

Dopamine
Memantine was shown in a study to act as an agonist at the dopamine D2HIGH receptor with equal or slightly higher affinity than to the NMDA receptors; however, the relevance of this may be negligible, as studies have shown very low affinity for binding to D2 receptors in general.

Sigmaergic
Memantine acts as an agonist at the σ1 receptor with a low affinity (Ki 2.6 μM). The consequences of this activity are unclear (as the role of sigma receptors in general is not yet that well understood). Due to this low affinity, therapeutic concentrations of memantine are most likely too low to have any sigmaergic effect as a typical therapeutic dose is 20 mg, however excessive doses of memantine taken for recreational purposes many times greater than prescribed doses may indeed activate this receptor.

History
Memantine was first synthesized and patented by Eli Lilly and Company in 1968 as an anti-diabetic agent, but it was ineffective at lowering blood sugar. Later it was discovered to have CNS activity, and was developed by Merz for dementia in Germany; the NMDA activity was discovered after trials had already begun. Memantine was first marketed for dementia in Germany in 1989 under the name Axura.In the US, some CNS activities were discovered at Childrens Hospital of Boston in 1990, and Childrens licensed patents covering uses of memantine outside the field of ophthalmology to Neurobiological Technologies (NTI) in 1995. In 1998 NTI amended its agreement with Childrens to allow Merz to take over development.In 2000, Merz partnered with Forest to develop the drug for Alzheimers disease in the U.S. under the name Namenda.In 2000, Merz partnered with Suntory for the Japanese market and with Lundbeck for other markets including Europe; the drug was originally marketed by Lundbeck under the name Ebixa.Sales of the drug reached $1.8 billion for 2014. The cost of Namenda was $269 to $489 a month in 2012.In February 2014, as the July 2015 patent expiration for memantine neared, Actavis, which had acquired Forest, announced that it was launching an extended release (XR) form of memantine that could be taken once a day instead of twice a day as needed with the then-current "immediate release" (IR) version, and that it intended to stop selling the IR version in August 2014 and withdraw the marketing authorization </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Interferon gamma and can you explain it in depth? [/INST] Interferon gamma (IFN-γ) is a dimerized soluble cytokine that is the only member of the type II class of interferons. The existence of this interferon, which early in its history was known as immune interferon, was described by E. F. Wheelock as a product of human leukocytes stimulated with phytohemagglutinin, and by others as a product of antigen-stimulated lymphocytes. It was also shown to be produced in human lymphocytes. or tuberculin-sensitized mouse peritoneal lymphocytes challenged with Mantoux test (PPD); the resulting supernatants were shown to inhibit growth of vesicular stomatitis virus.  Those reports also contained the basic observation underlying the now widely employed IFN-γ release assay used to test for tuberculosis.  In humans, the IFN-γ protein is encoded by the IFNG gene.

Function
IFN-γ, or type II interferon, is a cytokine that is critical for innate and adaptive immunity against viral, some bacterial and protozoan infections. IFN-γ is an important activator of macrophages and inducer of major histocompatibility complex class II molecule expression. Aberrant IFN-γ expression is associated with a number of autoinflammatory and autoimmune diseases. The importance of IFN-γ in the immune system stems in part from its ability to inhibit viral replication directly, and most importantly from its immunostimulatory and immunomodulatory effects. IFN-γ is produced predominantly by natural killer cells (NK) and natural killer T cells (NKT) as part of the innate immune response, and by CD4 Th1 and CD8 cytotoxic T lymphocyte (CTL) effector T cells once antigen-specific immunity develops as part of the adaptive immune response. IFN-γ is also produced by non-cytotoxic innate lymphoid cells (ILC), a family of immune cells first discovered in the early 2010s.

Structure
The IFN-γ monomer consists of a core of six α-helices and an extended unfolded sequence in the C-terminal region. This is shown in the structural models below. The α-helices in the core of the structure are numbered 1 to 6.

The biologically active dimer is formed by anti-parallel inter-locking of the two monomers as shown below. In the cartoon model, one monomer is shown in red, the other in blue.

Receptor binding
Cellular responses to IFN-γ are activated through its interaction with a heterodimeric receptor consisting of Interferon gamma receptor 1 (IFNGR1) and Interferon gamma receptor 2 (IFNGR2). IFN-γ binding to the receptor activates the JAK-STAT pathway. Activation of the JAK-STAT pathway induces upregulation of interferon-stimulated genes (ISGs), including MHC II. IFN-γ also binds to the glycosaminoglycan heparan sulfate (HS) at the cell surface. However, in contrast to many other heparan sulfate binding proteins, where binding promotes biological activity, the binding of IFN-γ to HS inhibits its biological activity.The structural models shown in figures 1-3 for IFN-γ are all shortened at their C-termini by 17 amino acids. Full length IFN-γ is 143 amino acids long, the models are 126 amino acids long. Affinity for heparan sulfate resides solely within the deleted sequence of 17 amino acids. Within this sequence of 17 amino acids lie two clusters of basic amino acids termed D1 and D2, respectively. Heparan sulfate interacts with both of these clusters. In the absence of heparan sulfate the presence of the D1 sequence increases the rate at which IFN-γ-receptor complexes form. Interactions between the D1 cluster of amino acids and the receptor may be the first step in complex formation. By binding to D1 HS may compete with the receptor and prevent active receptor complexes from forming.
The biological significance of heparan sulfates interaction with IFN-γ is unclear; however, binding of the D1 cluster to HS may protect it from proteolytic cleavage.

Biological activity
IFN-γ is secreted by T helper cells (specifically, Th1 cells), cytotoxic T cells (TC cells), macrophages, mucosal epithelial cells and NK cells. IFN-γ is both an important autocrine signal for professional APCs in early innate immune response, and an important paracrine signal in adaptive immune response. The expression of IFN-γ is induced by the cytokines IL-12, IL-15, IL-18, and type I IFN. IFN-γ is the only Type II interferon and it is serologically distinct from Type I interferons; it is acid-labile, while the type I variants are acid-stable.
IFN-γ has antiviral, immunoregulatory, and anti-tumor properties. It alters transcription in up to 30 genes producing a variety of physiological and cellular responses. Among the effects are:

Promotes NK cell activity
Increases antigen presentation and lysosome activity of macrophages.
Activates inducible nitric oxide synthase (iNOS)
Induces the production of IgG2a and IgG3 from activated plasma B cells
Causes normal cells to increase expression of class I MHC molecules as well as class II MHC on antigen-presenting cells—to be specific, through induction of antigen processing genes, including subunits of the immunoproteasome (MECL1, LMP2, LMP7), as well as TAP and ERAAP in addition possibly to the direct upregulation of MHC heavy chains and B2-microglobulin itself
Promotes adhesion and binding required for leukocyte migration
Induces the expression of intrinsic defense factors—for example, with respect to retroviruses, relevant genes include TRIM5alpha, APOBEC, and Tetherin, representing directly antiviral effects
Primes alveolar macrophages against secondary bacterial infections.IFN-γ is the primary cytokine that defines Th1 cells: Th1 cells secrete IFN-γ, which in turn causes more undifferentiated CD4+ cells (Th0 cells) to differentiate into Th1 cells
, representing a positive feedback loop—while suppressing Th2 cell differentiation. (Equivalent defining cytokines for other cells include IL-4 for Th2 cells and IL-17 for Th17 cells.)
NK cells and CD8+ cytotoxic T cells also produce IFN-γ. IFN-γ suppresses osteoclast formation by rapidly degrading the RANK adaptor protein TRAF6 in the RANK-RANKL signaling pathway, which otherwise stimulates the production of NF-κB.

Activity in granuloma formation
A granuloma is the bodys way of dealing with a substance it cannot remove or sterilize. Infectious causes of granulomas (infections are typically the most common cause of granulomas) include tuberculosis, leprosy, histoplasmosis, cryptococcosis, coccidioidomycosis, blastomycosis, and toxoplasmosis. Examples of non-infectious granulomatous diseases are sarcoidosis, Crohns disease, berylliosis, giant-cell arteritis, granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, pulmonary rheumatoid nodules, and aspiration of food and other particulate material into the lung. The infectious pathophysiology of granulomas is discussed primarily here.
The key association between IFN-γ and granulomas is that IFN-γ activates macrophages so that they become more powerful in killing intracellular organisms. Activation of macrophages by IFN-γ from Th1 helper cells in mycobacterial infections allows the macrophages to overcome the inhibition of phagolysosome maturation caused by mycobacteria (to stay alive inside macrophages). The first steps in IFN-γ-induced granuloma formation are activation of Th1 helper cells by macrophages releasing IL-1 and IL-12 in the presence of intracellular pathogens, and presentation of antigens from those pathogens. Next the Th1 helper cells aggregate around the macrophages and release IFN-γ, which activates the macrophages. Further activation of macrophages causes a cycle of further killing of intracellular bacteria, and further presentation of antigens to Th1 helper cells with further release of IFN-γ. Finally, macrophages surround the Th1 helper cells and become fibroblast-like cells walling off the infection.

Activity during pregnancy
Uterine Natural Killer cells (NK) secrete high levels of chemoattractants, such as IFN-γ in mice. IFN-γ dilates and thins the walls of maternal spiral arteries to enhance blood flow to the implantation site. This remodeling aids in the development of the placenta as it invades the uterus in its quest for nutrients. IFN-γ knockout mice fail to initiate normal pregnancy-induced modification of decidual arteries. These models display abnormally low amounts of cells or necrosis of decidua.In humans, elevated levels of IFN-γ have been associated with increased risk of miscarriage. Correlation studies have observed high IFN-γ levels in women with a history of spontaneous miscarriage, when compared to women with no history of spontaneous miscarriage. Additionally, low-IFN-γ levels are associated with women who successfully carry to term. It is possible that IFN-γ is cytotoxic to trophoblasts, which leads to miscarriage. However, causal research on the relationship between IFN-γ and miscarriage has not been performed due to ethical constraints.

Production
Recombinant human IFN-γ, as an expensive biopharmaceutical, has been expressed in different expression systems including prokaryotic, protozoan, fungal (yeasts), plant, insect and mammalian cells. Human IFN-γ is commonly expressed in Escherichia coli, marketed as ACTIMMUNE®, however, the resulting product of the prokaryotic expression system is not glycosylated with a short half-life in the bloodstream after injection; the purification process from bacterial expression system is also very costly. Other expression systems like Pichia pastoris did not show satisfactory results in terms of yields.

Therapeutic use
Interferon-γ 1b is approved by the U.S. Food and Drug Administration to treat chronic granulomatous disease (CGD) and osteopetrosis. The mechanism by which IFN-γ benefits CGD is via enhancing the efficacy of neutrophils against catalase-positive bacteria by correcting patients oxidative metabolism.It was not approved to treat idiopathic pulmonary fibrosis (IPF). In 2002, the manufacturer InterMune issued a press release saying that phase III data demonstrated survival benefit in IPF and reduced mortality by 70% in patients with mild to moderate disease. The U.S. Department of Justice charged that the release contained false and misleading statements. InterMunes chief executive, Scott Harkonen, was accused of manipulating the trial data, was convicted in 2009 of wire fraud, and was sentenced to fines and community service. Harkonen appealed his conviction to the U.S. Court of Appeals for the Ninth Circuit, and lost. Harkonen was granted a full pardon on January 20, 2021.Preliminary research on the role of IFN-γ in treating Friedreichs ataxia (FA) conducted by Children’s Hospital of Philadelphia has found no beneficial effects in short-term (< 6-months) treatment. However, researchers in Turkey have discovered significant improvements in patients gait and stance after 6 months of treatment.Although not officially approved, Interferon-γ has also been shown to be effective in treating patients with moderate to severe atopic dermatitis. Specifically, recombinant IFN-γ therapy has shown promise in patients with lowered IFN-γ expression, such as those with predisposition to herpes simplex virus, and pediatric patients.

Potential use in immunotherapy
IFN-γ increases an anti-proliferative state in cancer cells, while upregulating MHC I and MHC II expression, which increases immunorecognition and removal of pathogenic cells. IFN-γ also reduces metastasis in tumors by upregulating fibronectin, which negatively impacts tumor architecture.IFN-γ is not approved yet for the treatment in any cancer immunotherapy. However, improved survival was observed when IFN-γ was administrated to patients with bladder carcinoma and melanoma cancers. The most promising result was achieved in patients with stage 2 and 3 of ovarian carcinoma. On the contrary, it was stressed: "Interferon-γ secreted by CD8-positive lymphocytes upregulates PD-L1 on ovarian cancer cells and promotes tumour growth." The in vitro study of IFN-γ in cancer cells is more extensive and results indicate anti-proliferative activity of IFN-γ leading to the growth inhibition or cell death, generally induced by apoptosis but sometimes by autophagy. In addition, it has been reported that mammalian glycosylation of recombinant human IFN-γ, expressed in HEK293, improves its therapeutic efficacy compared to the unglycosylated form that is expressed in E </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Trastuzumab/hyaluronidase and can you explain it in depth? [/INST] Trastuzumab/hyaluronidase, sold under the brand name Herceptin SC among others, is a fixed-dose combination medication for the treatment of HER2-overexpressing breast cancer in adults. It is a combination of trastuzumab and hyaluronidase.The most common adverse reactions include fatigue, arthralgia, diarrhea, injection site reaction, upper respiratory tract infection, rash, myalgia, nausea, headache, edema, flushing, pyrexia, cough, and pain in extremity.Trastuzumab/hyaluronidase was approved for medical use in the European Union in August 2013. Trastuzumab/hyaluronidase was approved for medical use in the United States in February 2019.

Medical uses
Trastuzumab/hyaluronidase is indicated for adjuvant treatment of adults with HER2 overexpressing node positive or node negative (ER/PR negative or with one high risk feature; and it is indicated in combination with paclitaxel for first-line treatment of HER2-overexpressing metastatic breast cancer.

History
Trastuzumab/hyaluronidase (Herceptin SC) was approved for medical use in the European Union in August 2013.Trastuzumab/hyaluronidase (Herceptin Hylecta) was approved for medical use in the United States in February 2019.Approval of trastuzumab/hyaluronidase was based on two randomized trials, HannaH (NCT00950300) and SafeHER (NCT01566721). In HannaH, 596 participants with HER2-positive operable or locally advanced breast cancer, including inflammatory breast cancer, were randomized to receive 8 cycles of either trastuzumab/hyaluronidase or intravenous trastuzumab concurrently with chemotherapy, followed by surgery and continued therapy with either trastuzumab/hyaluronidase or intravenous trastuzumab, for an additional 10 cycles. HannaH demonstrated comparability between trastuzumab/hyaluronidase and intravenous trastuzumab based on co-primary endpoints of pathologic complete response and pharmacokinetics. Pathological complete response (pCR) was observed in 118 participants (45.4%) on the trastuzumab/hyaluronidase arm and in 107 participants (40.7%) receiving intravenous trastuzumab (95% CI for difference in pCR: -4.0; 13.4).SafeHER was a prospective, two-cohort, non-randomized, multinational, open-label trial assessing the overall safety and tolerability of trastuzumab/hyaluronidase with chemotherapy in 1,864 participants with HER2-positive breast cancer. Participants received a fixed dose of 600 mg trastuzumab/hyaluronidase every 3 weeks for 18 cycles. trastuzumab/hyaluronidase was initiated either sequentially with chemotherapy, concurrently with chemotherapy, or without adjuvant chemotherapy, or in combination with neoadjuvant chemotherapy followed by trastuzumab.

References
Further reading
"Application for the addition of Herceptin (trastuzmab) on the WHO Model List of Essential Medicines" (PDF). F. Hoffmann-La Roche Ltd. 7 December 2018.

External links
"Trastuzumab" </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Solifenacin and can you explain it in depth? [/INST] Solifenacin, sold as the brand name Vesicare among others, is a medicine used to treat overactive bladder and neurogenic detrusor overactivity (NDO). It may help with incontinence, urinary frequency, and urinary urgency. Benefits appear similar to other medications in the class. It is taken by mouth.Common side effects include dry mouth, constipation, and urinary tract infection. Severe side effects may include urinary retention, QT prolongation, hallucinations, glaucoma, and anaphylaxis. It is unclear if use is safe during pregnancy. It is of the antimuscarinic class and works by decreasing bladder contractions.Solifenacin was approved for medical use in the United States in 2004. In 2017, it was the 283rd most commonly prescribed medication in the United States, with more than one million prescriptions.

Medical use
It is used to treat overactive bladder. It may help with incontinence, urinary frequency, and urinary urgency.Benefits appear similar to other antimuscarinics such as oxybutynin, tolterodine, and darifenacin.It is also used to treat neurogenic detrusor overactivity (NDO), a form of bladder dysfunction related to neurological impairment, in children ages two years and older. NDO is a dysfunction of the bladder that results from disease or injury in the nervous system. NDO may be related to congenital conditions (often-inherited conditions beginning at or before birth), such as spina bifida (myelomeningocele), or other conditions such as spinal cord injury. With NDO, there is overactivity of the bladder wall muscle, which normally relaxes to allow storage of urine. The bladder wall muscle overactivity results in sporadic bladder muscle contraction, which increases pressure in the bladder and decreases the volume of urine the bladder can hold. If NDO is not treated, increased pressure in the bladder can put the upper urinary tract at risk of harm, including possible permanent damage to the kidneys. In addition, spontaneous bladder muscle contractions can lead to unexpected and frequent leakage of urine with symptoms of urinary urgency (immediate urge to urinate), frequency (urinating more often than normal) and incontinence (loss of bladder control).

Contraindications
Solifenacin is contraindicated for people with urinary retention, gastric retention, uncontrolled or poorly controlled closed-angle glaucoma, severe liver disease (Child-Pugh class C), and hemodialysis.Long QT syndrome is not a contraindication although solifenacin, like tolterodine and darifenacin, binds to hERG channels of the heart and may prolong the QT interval. This mechanism appears to be seldom clinically relevant.Solifenacin is not to be used in people with gastric retention (reduced emptying of the stomach), uncontrolled narrow angle glaucoma (fluid buildup in the eye which raises eye pressure) or hypersensitivity (allergic reaction) to solifenacin or any of its components. Solifenacin is also not recommended for use in people with severe liver failure, clinically significant bladder outlet obstruction in the absence of clean intermittent catheterization, decreased gastrointestinal motility (slowed intestinal contractions), or at high risk of QT prolongation (an electrical disturbance where the heart muscle takes longer than normal to recharge between beats), including people with a known history of QT prolongation and people taking medications known to prolong the QT interval.

Side effects
The most common side effects of solifenacin are dry mouth, constipation and urinary tract infection. As all anticholinergics, solifenacin may rarely cause hyperthermia due to decreased perspiration. Somnolence (sleepiness or drowsiness) has been reported. Severe allergic reactions, such as angioedema (swelling beneath the skin) and anaphylaxis, have been reported in people treated with solifenacin succinate and may be life-threatening.

Interactions
Solifenacin is metabolized in the liver by the cytochrome P450 enzyme CYP3A4. When administered concomitantly with drugs that inhibit CYP3A4, such as ketoconazole, the metabolism of solifenacin is impaired, leading to an increase in its concentration in the body and a reduction in its excretion.As stated above, solifenacin may also prolong the QT interval. Therefore, administering it concomitantly with drugs which also have this effect, such as moxifloxacin or pimozide, can theoretically increase the risk of arrhythmia.

Pharmacology
Mechanism of action
Solifenacin is a competitive cholinergic receptor antagonist, selective for the M3 receptor subtype. The binding of acetylcholine to these receptors, particularly M3, plays a critical role in the contraction of smooth muscle.
By preventing the binding of acetylcholine to these receptors, solifenacin reduces smooth muscle tone in the bladder, allowing the bladder to retain larger volumes of urine and reducing the number of micturition, urgency and incontinence episodes. Because of a long elimination half life, a once-a-day dose can offer 24-hour control of the urinary bladder smooth muscle tone.

Pharmacokinetics
Peak plasma concentrations are reached three to eight hours after absorption from the gut. In the bloodstream, 98% of the substance are bound to plasma proteins, mainly acidic ones. Metabolism is mediated by the liver enzyme CYP3A4 and possibly others. There is one known active metabolite, 4R-hydroxysolifenacin, and three inactive ones, the N-glucuronide, the N-oxide and the 4R-hydroxy-N-oxide. The elimination half-life is 45 to 68 hours. 69% of the substance, both in its original form and as metabolites, are excreted renally and 23% via the feces.

Chemistry
Like other anticholinergics, solifenacin is an ester of a carboxylic acid containing (at least) an aromatic ring with an alcohol containing a nitrogen atom. While in the prototype anticholinergic atropine the bicyclic ring is tropane, solifenacin replaces it with quinuclidine.
The free base is a yellow oil, while the salt solifenacin succinate forms yellowish crystals.

History
The compound was studied using animal models by the Yamanouchi Pharmaceutical Co., Ltd. of Tokyo, Japan. It was known as YM905 when under study in the early 2000s.Solifenacin was approved for medical used in the United States in 2004 with an indication to treat overactive bladder in adults 18 years and older.In May 2020, solifenacin was approved for medical use in the United States with an indication to treat neurogenic detrusor overactivity (NDO), a form of bladder dysfunction related to neurological impairment, in children ages two years and older.The efficacy of solifenacin to treat neurogenic detrusor overactivity (NDO) was established in two clinical trials with a total of 95 pediatric NDO participants, ages two to 17 years old. The studies were designed to measure (as a primary efficacy endpoint) the maximum amount of urine the bladder could hold after 24 weeks of treatment. In the first study, 17 participants ages two to less than five years old were able to hold an average of 39 mL more urine than when the study began. In the second study, 49 participants ages five to 17 years were able to hold an average of 57 mL more urine than when the study began </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Griseofulvin and can you explain it in depth? [/INST] Griseofulvin is an antifungal medication used to treat a number of types of dermatophytoses (ringworm). This includes fungal infections of the nails and scalp, as well as the skin when antifungal creams have not worked. It is taken by mouth.Common side effects include allergic reactions, nausea, diarrhea, headache, trouble sleeping, and feeling tired. It is not recommended in people with liver failure or porphyria. Use during or in the months before pregnancy may result in harm to the baby. Griseofulvin works by interfering with fungal mitosis.Griseofulvin was discovered in 1939 from the soil fungus Penicillium griseofulvum. It is on the World Health Organizations List of Essential Medicines.

Medical uses
Griseofulvin is used orally only for dermatophytosis. It is ineffective topically. It is reserved for cases in which topical treatment with creams is ineffective.Terbinafine given for 2 to 4 weeks is at least as effective as griseofulvin given for 6 to 8 weeks for treatment of Trichophyton scalp infections. However, griseofulvin is more effective than terbinafine for treatment of Microsporum scalp infections.

Pharmacology
Pharmacodynamics
The drug binds to tubulin, interfering with microtubule function, thus inhibiting mitosis.
It binds to keratin in keratin precursor cells and makes them resistant to fungal infections. The drug reaches its site of action only when hair or skin is replaced by the keratin-griseofulvin complex. Griseofulvin then enters the dermatophyte through energy-dependent transport processes and binds to fungal microtubules. This alters the processing for mitosis and also underlying information for deposition of fungal cell walls.

Biosynthetic process
It is produced industrially by fermenting the fungus Penicillium griseofulvum.The first step in the biosynthesis of griseofulvin by P. griseofulvin is the synthesis of the 14-carbon poly-β-keto chain by a type I iterative polyketide synthase (PKS) via iterative addition of 6 malonyl-CoA to an acyl-CoA starter unit. The 14-carbon poly-β-keto chain undergoes cyclization/aromatization, using cyclase/aromatase, respectively, through a Claisen and aldol condensation to form the benzophenone intermediate. The benzophenone intermediate is then methylated via S-adenosyl methionine (SAM) twice to yield griseophenone C. The griseophenone C is then halogenated at the activated site ortho to the phenol group on the left aromatic ring to form griseophenone B. The halogenated species then undergoes a single phenolic oxidation in both rings forming the two oxygen diradical species </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Clozapine and can you explain it in depth? [/INST] Clozapine is a psychiatric medication and is the first atypical antipsychotic (also called second-generation antipsychotic). It is primarily used to treat people with schizophrenia and schizoaffective disorders who have had an inadequate response to other antipsychotics or who have been unable to tolerate other drugs due to extrapyramidal side effects. It is also used for the treatment of psychosis in Parkinsons disease. Clozapine is regarded as the gold-standard treatment when other medication has been insufficiently effective and its use is recommended by multiple international treatment guidelines, after resistance to earlier neuroleptic treatment is established.The role of clozapine in treatment-resistant schizophrenia was established by a 1988 landmark study in which clozapine showed marked benefits compared to chlorpromazine in a group of patients with protracted psychosis who had already shown an inadequate response to other antipsychotics. While there are significant side effects, clozapine remains the most effective treatment when one or more other antipsychotics have had an inadequate response. The use of clozapine is associated with multiple improved outcomes, including a reduced rate of all-cause mortality, suicide and hospitalization. In a 2013 network comparative meta-analysis of 15 antipsychotic drugs, clozapine was found to be significantly more effective than all other drugs. In a 2021 UK study, the majority of patients (over 85% of respondents) who took clozapine preferred it to their previous therapies, felt better on it and wanted to keep taking it. In a 2000 Canadian survey of 130 patients, the majority reported better satisfaction, quality of life, compliance with treatment, thinking, mood, and alertness.Compared to other antipsychotics, clozapine has an increased risk of blood dyscrasias, in particular agranulocytosis, in the first 18 weeks of treatment. After one year, this risk reduces to that associated with most antipsychotics. Clozapines use is therefore reserved for people who have not responded to two other antipsychotics and is only done with stringent blood monitoring. Overall, despite the concerns relating to blood and other side effects, clozapine use is associated with a reduced mortality, especially from suicide which is a major cause of premature death in people with schizophrenia. The risk of clozapine related agranulocytosis and neutropenia warranted the mandatory use of stringent risk monitoring and management systems, which have reduced the risk of death from these adverse events to around 1 in 7,700. The association between clozapine use and specific bloods dyscrasias was first noted in the 1970s when eight deaths from agranulocytosis were noted in Finland. At the time it was not clear if this exceeded the established rate of this side effect which is also found in other antipsychotics and although the drug was not completely withdrawn, its use became limited. Clozapine became widely available in the early 1990s and remains the only treatment likely to be effective in treating resistant schizophrenia.
Common adverse effects include drowsiness, constipation, hypersalivation (increased saliva production), tachycardia, low blood pressure, blurred vision, weight gain, and dizziness. Clozapine is not normally associated with tardive dyskinesia (TD) and is recommended as the drug of choice when this is present, although some case reports describe clozapine-induced TD. Other serious risks include seizures, inflammation of the heart, high blood sugar levels, constipation. The use of this drug can rarely result in clozapine-induced gastric hypomotility syndrome which may lead to bowel obstruction and death, and in older people with psychosis, as a result of dementia it may lead to an increased risk of death. The mechanism of action is not entirely clear in the current medical literature. Clozapine is on the World Health Organizations List of Essential Medicines. It is available as a generic medication.

History
Clozapine was synthesized in 1958 by Wander AG, a Swiss pharmaceutical company, based on the chemical structure of the tricyclic antidepressant imipramine. The first test in humans in 1962 was considered a failure. Trials in Germany in 1965 and 1966 as well as a trial in Vienna in 1966 were successful. In 1967 Wander AG was acquired by Sandoz. Further trials took place in 1972 when clozapine was released in Switzerland and Austria as Leponex. Two years later it was released in West Germany and in Finland in 1975. Early testing was performed in the United States around the same time. In 1975,  16 cases of agranulocytosis leading to 8 deaths in clozapine-treated patients, reported from 6 hospitals mostly in southwestern Finland, led to concern. Analysis of the Finnish cases revealed that all the agranulocytosis cases had occurred within the first 18 weeks of treatment and the authors proposed blood monitoring during this period. The rate of agranulocytosis in Finland appeared to be 20 times higher than in the rest of the world and there was speculation that this may have been due a unique genetic diversity in the region. Whilst the drug continued to be manufactured by Sandoz, and remained available in Europe, development in the U.S. halted.
Interest in clozapine continued in an investigational capacity in the United States because, even in the 1980s, the duration of hospitalisation, especially in State Hospitals for those with treatment resistant schizophrenia might often be measured in years rather than days. The role of clozapine in treatment resistant schizophrenia was established by the landmark Clozaril Collaborative Study Group Study #30 in which clozapine showed marked benefits compared to chlorpromazine in a group of patients with protracted psychosis and who had already shown an inadequate response to other antipsychotics. This involved both stringent blood monitoring and a double-blind design with the power to demonstrate superiority over standard antipsychotic treatment. The inclusion criteria were patients who had failed to respond to at least three previous antipsychotics and had then not responded to a single blind treatment with haloperidol (mean dose 61 mg +/- 14 mg/d). Two hundred and sixty-eight were randomised were to double blind trials of clozapine (up to 900 mg/d)  or chlorpromazine (up to 1800 mg/d). 30% of the clozapine patients responded compared to 4% of the controls, with significantly greater improvement on the Brief Psychiatric Rating Scale, Clinical Global Impression Scale, and Nurses Observation Scale for Inpatient Evaluation; this improvement included "negative" as well as positive symptom areas. Following this study, the US Food and Drug Administration (FDA) approved its use in 1990. Cautious of this risk, however, the FDA required a black box warning for specific side effects including agranulocytosis, and took the unique step of requiring patients to be registered in a formal system of tracking so that blood count levels could be evaluated on a systematic basis.In December 2002, clozapine was approved in the US for reducing the risk of suicide in people with schizophrenia or schizoaffective  judged to be at chronic risk for suicidal behavior. In 2005, the FDA approved criteria to allow reduced blood monitoring frequency. In 2015, the individual manufacturer Patient Registries were consolidated by request of the FDA into a single shared Patient Registry Called The Clozapine REMS Registry. Despite the demonstrated safety of the new FDA monitoring requirements, which have lower neutrophil levels and do not include total white cell counts, international monitoring has not been standardised.

Chemistry
Clozapine is a dibenzodiazepine that is structurally very similar to loxapine (originally deemed a typical antipsychotic). It is slightly soluble in water, soluble in acetone, and highly soluble in chloroform. Its solubility in water is 0.1889 mg/L (25 °C). Its manufacturer, Novartis, claims a solubility of <0.01% in water (<100 mg/L).

Clinical uses
Schizophrenia
Clozapine is usually used for people diagnosed with schizophrenia who have had an inadequate response to other antipsychotics or who have been unable to tolerate other drugs due to extrapyramidal side effects. It is also used for the treatment of psychosis in Parkinsons Disease. It is regarded as the gold-standard treatment when other medication has been insufficiently effective and its use is recommended by multiple international treatment guidelines, supported by systematic reviews and meta-analysis. Whilst all current guidelines reserve clozapine to individuals when two other antipsychotics evidence indicates that clozapine might be used as a second line drug. Clozapine treatment has been demonstrated to produced improved outcomes in multiple domains including; a reduced risk of hospitalisation, a reduced risk of drug discontinuation, a reduction in overall symptoms and has improved efficacy in the treatment of positive psychotic symptoms of schizophrenia. Despite a range of side effects patients report good levels of satisfaction and long term adherence is favourable compared to other antipsychotics. Very long term follow-up studies reveal multiple benefits in terms of reduced mortality, with a particularly strong effect for reduced death by suicide, clozapine is the only antipsychotic known to have an effect reducing the risk of suicide or attempted suicide. Clozapine has a significant anti-aggressive effect. Clozapine is widely used in secure and forensic mental health settings where improvements in aggression, shortened admission and reductions in restrictive practice such as seclusion have been found. In secure hospitals and other settings clozapine has also been used in the treatment of borderline and antisocial personality disorder when this has been associated with violence or self-harm. Although oral treatment is almost universal clozapine has on occasion been enforced using either nasogastric or a short acting injection although in almost 50% of the approximately 100 reported cases patients agreed to take oral medication prior to the use of a coercive intervention. Clozapine has also been used off-label to treat catatonia with success in over 80% of cases.

Bipolar disorder
On the basis of systematic reviews clozapine is recommended in some treatment guidelines as a third or fourth line treatment for bipolar disorder. Bipolar disorder is an unlicensed indication for clozapine.

Severe personality disorders
Clozapine is also used in emotionally unstable personality disorder and a randomised controlled trial is currently underway. The use of clozapine to treat personality disorder is uncommon and unlicensed.

Initiation
Whilst clozapine is usually initiated in hospital setting community initiation is also available. Before clozapine can be initiated multiple assessments and baseline investigations are performed. In the UK and Ireland there must be an assessment that the patient satisfies the criteria for prescription; treatment resistant schizophrenia, intolerance due to extrapyramidal symptoms of other antipsychotics or psychosis in Parkinsons disease. Establishing a history of treatment resistance may include careful review of the medication history including the durations, doses and compliance of previous antipsychotic therapy and that these did not have an adequate clinical effect. A diagnostic review may also be performed. That could include review of antipsychotic plasma concentrations if available. The prescriber, patient, pharmacy  and the laboratory performing blood counts are all registered with a specified clozapine provider who must be advised that there is no history of neutropenia from any cause. The clozapine providers collaborate by sharing information regarding patients who have had clozapine related neutropenia or agranulocytosis so that clozapine cannot be used again on license. Clozapine may only be dispensed after a satisfactory blood result has been received by the risk monitoring agency at which point an individual prescription may be released to an individual patient only.Baseline tests usually also include; a physical examination including baseline weight, waist circumference and BMI, assessments of renal function and liver function, an ECG and other baseline bloods may also be taken to facilitate monitoring of possible myocarditis, these might include C reactive protein (CRP) and troponin. In Australia and New Zealand pre-clozapine echocardiograms are also commonly performed. A number of service protocols are available and there are variations in the extent of preclozapine work ups. Some might also include fasting lipids, HbA1c and prolactin. At the Maudsley Hospital in the UK the Treat service also routinely performs a wide variety of other investigations including multiple investigations for other causes of psychosis and comorbidities including; MRI brain imaging, thyroid function tests, B12, folate and serum calcium levels, infection screening for blood borne viruses including Hepatitis B and C, HIV and syphilis as well as screening for autoimmune psychosis by anti-NMDA, anti-VGKC and Anti-nuclear Antibody  screening. Investigations used to monitor the possibility of clozapine related side effects such as myocarditis are also performed including baseline troponin, CRP and BNP and for neuroleptic malignant syndrome CK.The dose of clozapine is initially low and gradually increased over a number of weeks. Initial doses may range from 6.5 to 12.5 mg/d increasing stepwise typically to doses in the range of 250–350 mg per day at which point an assessment of response will be performed. In the UK the average clozapine dose is 450 mg/d. But response is highly variable and some patients respond at much lower doses and vice versa.

Monitoring
During the initial dose titration phase the following are typically monitored; usually daily at first; pulse, blood pressure and since orthostatic hypotension can be problematic this should be monitored both sitting and standing. If there is a significant drop then the rate of the dose increase may be slowed, temperature.Weekly tests include; Mandatory full blood counts are performed weekly for the first 18 weeks. In some services there will also be monitoring of markers that might indicate myocarditis; troponin, CRP and BNP although the exact tests and frequency vary between services. Weight is usually measured weekly.
Thereon other investigations and monitoring will always include full blood counts (fortnightly for 1 year then monthly). Weight, waist circumference, lipids and glucose or HbA1c may also be monitored.

Clozapine Response and Treatment Optimisation
As with other antipsychotics, and in contrast to received wisdom, responses to clozapine are typically seen soon after initiation and often within the first week. That said responses, especially those which are partial, can be delayed. Quite what an adequate trial of clozapine is, is uncertain but a recommendation is that this should be for at least 8 weeks on a plasma trough level above 350-400 micro g/L. There is considerable inter-individual variation. A significant number of patients respond at lower and also much higher plasma concentrations and some patients, especially young male smokers may never achieve these plasma levels even at doses of 900 mg/day. Options then include either increasing the dose above the licensed maximum or the addition of a drug that inhibits clozapine metabolism. Avoiding unnecessary polypharmacy is a general principle in drug treatment.

Optimising blood sampling
The neutrophil cut off for clozapine have shown an exceptional ability to mitigate the risk of neutropenia and agranulocytosis. There is a significant margin of safety. Some patients may have marginal neutrophil counts before and after initiation and they are at risk of premature clozapine discontinuation. A knowledge of neutrophil biology allows blood sampling optimisation. Neutrophils show a diurnal variation in response to the natural cycle of G-CSF production, they are increased in the afternoons, they are also mobilised into the circulation after exercise and smoking. Simply shifting blood sampling has been shown to avoid unnecessary discontinuations, especially in black populations. However this is a disruption to usual hospital practice. Other practical steps are to ensure that blood results become available in hours and when senior staff are available.

Underuse of Clozapine
Clozapine is widely recognised as being underused with wide variation in prescribing, especially in patients with African heritage.Psychiatrists prescribing practices have been found to be the most significant variable regarding variance in its use. Surveys of psychiatrists attitudes to clozapine have found that many had little experience in its use, over estimated the incidence and were fearful of side effects, and did not appreciate that many patients prefer to take clozapine than other antipsychotics, are reluctant to prescribe clozapine, had little experience in its use and believed that patients treated with clozapine were less satisfied than those treated with other antipsychotics. In contrast to many psychiatrists expectations most patients believe that the blood testing and other difficulties are worth the multiple benefits that they perceive. Whilst psychiatrists fear the severe adverse effects such as agranulocytosis, patients are more concerned about hypersalivation. Clozapine is no longer actively marketed and this may also be one of the explanations for its underuse.Despite the strong evidence and universal endorsement by national and international treatment guidelines and the experiences of patients themselves, most people eligible for clozapine are not treated with it. A large study in England found that approximately 30% of those eligible for clozapine were being treated with it. Those patients that do start clozapine usually face prolonged delay, multiple episodes of psychosis and treatments such as high dose antipsychotics or polypharmacy. Instead of two previous antipsychotics many will have been exposed to ten or more drugs which were not effective. In a study of 120 patients conducted in four hospitals in South-East London, found a mean of 9.2 episodes of antipsychotic prescription before clozapine was initiated and the mean delay in using clozapine was 5 years. Treatments that have no evidence base or are regarded as actively harmful are used instead multiple and or high-dose treatment.

Racial disparity in the use of clozapine
A general finding in healthcare provision is that minority groups receive inferior treatment; this is a particular finding in the US. In the US a general finding is that compared to their white peers African American people are less likely to be prescribed the second generation antipsychotics, which are more expensive than alternatives and this was even apparent and especially so for clozapine when comparison was made in the Veterans Affairs medical system and when differences regarding socioeconomic factors were taken into account. As well as being less likely to start clozapine black patients are more likely to stop clozapine, possibly on account of benign ethnic neutropenia.

Benign ethnic neutropenia
Benign reductions in neutrophils are observed in individuals of all ethnic backgrounds ethnic neutropenia (BEN), neutropenia without immune dysfunction or increased liability to infection is not due to abnormal neutrophil production; although, the exact aetiology of the reduction in circulating cells remains unknown. BEN is associated with several ethnic groups, but in particular those with Black African and West African ancestry. A difficulty with the use of clozapine is that neutrophil counts have been standardised on white populations. For significant numbers of black patients the standard neutrophil count thresholds did not permit clozapine use as the thresholds did not take BEN into account. Since 2002, clozapine monitoring services in the UK have used reference ranges 0.5 × 109/l lower for patients with haematologically confirmed BEN and similar adjustments are available in the current US criteria, although with lower permissible minima. But even then significant numbers of black patients will not be eligible even though the low neutrophil counts do not in their case reflect disease. The Duffy–Null polymorphism, which protects against some types of malaria, is predictive of BEN.

Adverse effects
Clozapine may cause serious and potentially fatal adverse effects. Clozapine carries five black box warnings, including (1) severe neutropenia (low levels of neutrophils), (2) orthostatic hypotension (low blood pressure upon changing positions), including slow heart rate and fainting, (3) seizures, (4) myocarditis (inflammation of the heart), and (5) risk of death when used in elderly people with dementia-related psychosis. Lowering of the seizure threshold may be dose related. Increasing the dose slowly may decrease the risk for seizures and orthostatic hypotension.Common effects include constipation, bed-wetting, night-time drooling, muscle stiffness, sedation, tremors, orthostatic hypotension, high blood sugar, and weight gain. The risk of developing extrapyramidal symptoms, such as tardive dyskinesia, is below that of typical antipsychotics; this may be due to clozapines anticholinergic effects. Extrapyramidal symptoms may subside somewhat after a person switches from another antipsychotic to clozapine. Sexual problems, like retrograde ejaculation, have been reported while taking clozapine. Despite the risk for numerous side effects, many side effects can be managed while continuing to take clozapine.

Neutropenia and agranulocytosis
Clozapine Induced Neutropenia (CIN) occurs in approximately 3.8% of cases and Clozapine Induced Agranulocytosis (CIA) in 0.4%. These are potentially serious side effects and agranulocytosis can result in death. To mitigate this risk clozapine is only used with mandatory  absolute neutrophil count (ANC) monitoring (neutrophils are the most abundant of the granulocytes); for example, in the United States, the Risk Evaluation and Mitigation Strategy (REMS). The exact schedules and blood count thresholds vary internationally and the thresholds at which clozapine can be used in the U.S. has been lower than those currently used in the U.K. and Australasia for some time. The effectiveness of the risk management strategies used is such that deaths from these side effects are very rare occurring at approximately 1 in 7700 patients treated. Almost all the adverse blood reactions occur within the first year of treatment and the majority within the first 18 weeks. After one year of treatment these risks reduce markedly to that seen in other antipsychotic drugs 0.01% or about 1 in 10,000 and the risk of death is markedly lower still. When reductions in neutrophil levels are noted on regular blood monitoring then, depending on the value, monitoring may be increased or, if the neutrophil count is sufficiently low, then clozapine is stopped immediately and can then no longer be used within the medicinal licence. Stopping clozapine almost always results in resolution of the neutrophil reduction. However severe agranulocytosis can result in spontaneous infection and death, is a severe decrease in the amount of a specific kind of white blood cell called granulocytes. Clozapine carries a black box warning for drug-induced agranulocytosis. Rapid point-of-care tests may simplify the monitoring for agranulocytosis.

Clozapine rechallenge
A clozapine "rechallenge" is when someone that experienced agranulocytosis while taking clozapine starts taking the medication again. In countries in which the neutrophil thresholds are higher than those used in the US a simple approach is, if the lowest ANC had been above the US cut off, to reintroduce clozapine but with the US monitoring regime. This has been demonstrated in a large cohort of patients in a hospital in London in which it was found that of 115 patients who had had clozapine stopped according to the US criteria only 7 would have had clozapine stopped if the US cut offs had been used. Of these 62 were rechallenged, 59 continued to use clozapine without difficulty and only 1 had a fall in neutrophils below the US cut off. Other approaches have included the use of other drugs to support neutrophil counts including lithium or granulocyte colony-stimulating factor (G-CSF). However, if agranulocytosis still occurs during a rechallenge, the alternative options are limited.

Cardiac toxicity
Clozapine can rarely cause myocarditis and cardiomyopathy. A large meta-analysis of clozapine exposure to over 250,000 people revealed that these occurred in approximately 7 in 1000 patients treated and resulted in death in 3 and 4 in 10,000 patients exposed respectively and although myocarditis occurred almost exclusively within the first 8 weeks of treatment, cardiomyopathy can occur much later on. First manifestations of illness are fever which may be accompanied by symptoms associated with upper respiratory tract, gastrointestinal or urinary tract infection. Typically C-reactive protein (CRP) increases with the onset of fever and rises in the cardiac enzyme, troponin, occur up to 5 days later. Monitoring guidelines advise checking CRP and troponin at baseline and weekly for the first 4 weeks after clozapine initiation and observing the patient for signs and symptoms of illness. Signs of heart failure are less common and may develop with the rise in troponin. A recent case-control study found that the risk of clozapine-induced myocarditis is increased with increasing rate of clozapine dose titration, increasing age and concomitant sodium valproate. A large electronic health  register study has revealed that nearly 90% of cases of suspected clozapine related myocarditis are false positives. Rechallenge after clozapine induced myocarditis has been performed and a protocol for this specialist approach has been published. A systematic review of rechallenge after myocarditis has show success in over 60% of reported cases.

Gastrointestinal hypomotility
Another underrecognized and potentially life-threatening effect spectrum is gastrointestinal hypomotility, which may manifest as severe constipation, fecal impaction, paralytic ileus, bowel obstruction, acute megacolon, ischemia or necrosis. Colonic hypomotility has been shown to occur in up to 80% of people prescribed clozapine when gastrointestinal function is measured objectively using radiopaque markers. Clozapine-induced gastrointestinal hypomotility currently has a higher mortality rate than the better known side effect of agranulocytosis. A Cochrane review found little evidence to help guide decisions about the best treatment for gastrointestinal hypomotility caused by clozapine and other antipsychotic medication. Monitoring bowel function and the preemptive use of laxatives for all clozapine-treated people has been shown to improve colonic transit times and reduce serious sequelae.

Hypersalivation
Hypersalivation, or the excessive production of saliva, is one of the most common adverse effects of clozapine (30-80%). The saliva production is especially bothersome at night and first thing in the morning, as the immobility of sleep precludes the normal clearance of saliva by swallowing that occurs throughout the day. While clozapine is a muscarinic antagonist at the M1, M2, M3, and M5 receptors, clozapine is a full agonist at the M4 subset. Because M4 is highly expressed in the salivary gland, its M4 agonist activity is thought to be responsible for hypersalivation. Clozapine-induced hypersalivation is likely a dose-related phenomenon, and tends to be worse when first starting the medication. Besides decreasing the dose or slowing the initial dose titration, other interventions that have shown some benefit include systemically absorbed anticholinergic medications such as hyoscine, diphenhydramine and topical anticholinergic medications like ipratropium bromide. Mild hypersalivation may be managed by sleeping with a towel over the pillow at night.

Central nervous system
CNS side effects include drowsiness, vertigo, headache, tremor, syncope, sleep disturbances, nightmares, restlessness, akinesia, agitation, seizures, rigidity, akathisia, confusion, fatigue, insomnia, hyperkinesia, weakness, lethargy, ataxia, slurred speech, depression, myoclonic jerks, and anxiety. Rarely seen are delusions, hallucinations, delirium, amnesia, libido increase or decrease, paranoia and irritability, abnormal EEG, worsening of psychosis, paresthesia, status epilepticus, and obsessive compulsive symptoms. Similar to other antipsychotics clozapine rarely has been known to cause neuroleptic malignant syndrome.

Urinary incontinence
Clozapine is linked to urinary incontinence, though its appearance may be under-recognized.

Withdrawal effects
Abrupt withdrawal may lead to cholinergic rebound effects, such as indigestion, diarrhea, nausea/vomiting, overabundance of saliva, profuse sweating, insomnia, and agitation. Abrupt withdrawal can also cause severe movement disorders, catatonia, and psychosis. Doctors have recommended that patients, families, and caregivers be made aware of the symptoms and risks of abrupt withdrawal of clozapine. When discontinuing clozapine, gradual dose reduction is recommended to reduce the intensity of withdrawal effects.

Weight gain and diabetes
In addition to hyperglycemia, significant weight gain is frequently experienced by patients treated with clozapine. Impaired glucose metabolism and obesity have been shown to be constituents of the metabolic syndrome and may increase the risk of cardiovascular disease. The data suggest that clozapine may be more likely to cause adverse metabolic effects than some of the other atypical antipsychotics.

Pneumonia
International adverse drug effect databases indicate that clozapine use is associated with a significantly increased incidence of and death from pneumonia and this may be one of the most significant adverse events. The mechanisms for this are unknown although it has been speculated that it may be related to hypersalivation, immune effects of clozapines effects on the resolution of inflammation.

Overdose
Symptoms of overdose can be variable, but often include; sedation, confusion, tachycardia, seizures and ataxia. Fatalities have been reported due to clozapine overdose, though overdoses of greater than 5000 mg have been survived.

Drug interactions
Fluvoxamine inhibits the metabolism of clozapine leading to significantly increased blood levels of clozapine.When carbamazepine is concurrently used with clozapine, it has been shown to decrease plasma levels of clozapine significantly thereby decreasing the beneficial effects of clozapine. Patients should be monitored for "decreased therapeutic effects of clozapine if carbamazepine" is started or increased. If carbamazepine is discontinued or the dose of carbamazepine is decreased, therapeutic effects of clozapine should be monitored. The study recommends carbamazepine to not be used concurrently with clozapine due to increased risk of agranulocytosis.Ciprofloxacin is an inhibitor of CYP1A2 and clozapine is a major CYP1A2 substrate. Randomized study reported elevation in clozapine concentration in subjects concurrently taking ciprofloxacin. Thus, the prescribing information for clozapine recommends "reducing the dose of clozapine by one-third of original dose" when ciprofloxacin and other CYP1A2 inhibitors are added to therapy, but once ciprofloxacin is removed from therapy, it is recommended to return clozapine to original dose.

Pharmacology
Pharmacodynamics
Clozapine is classified as an atypical antipsychotic drug because it binds to serotonin as well as dopamine receptors.Clozapine is an antagonist at the 5-HT2A subunit of the serotonin receptor, putatively improving depression, anxiety, and the negative cognitive symptoms associated with schizophrenia.A direct interaction of clozapine with the GABAB receptor has also been shown. GABAB receptor-deficient mice exhibit increased extracellular dopamine levels and altered locomotor behaviour equivalent to that in schizophrenia animal models. GABAB receptor agonists and positive allosteric modulators reduce the locomotor changes in these models.Clozapine induces the release of glutamate and D-serine, an agonist at the glycine site of the NMDA receptor, from astrocytes, and reduces the expression of astrocytic glutamate transporters. These are direct effects that are also present in astrocyte cell cultures not containing neurons. Clozapine prevents impaired NMDA receptor expression caused by NMDA receptor antagonists.

Pharmacokinetics
The absorption of clozapine is almost complete following oral administration, but the oral bioavailability is only 60 to 70% due to first-pass metabolism. The time to peak concentration after oral dosing is about 2.5 hours, and food does not appear to affect the bioavailability of clozapine. However, it was shown that co-administration of food decreases the rate of absorption. The elimination half-life of clozapine is about 14 hours at steady state conditions (varying with daily dose).Clozapine is extensively metabolized in the liver, via the cytochrome P450 system, to polar metabolites suitable for elimination in the urine and feces. The major metabolite, norclozapine (desmethyl-clozapine), is pharmacologically active. The cytochrome P450 isoenzyme 1A2 is primarily responsible for clozapine metabolism, but 2C, 2D6, 2E1 and 3A3/4 appear to play roles as well. Agents that induce (e.g., cigarette smoke) or inhibit (e.g., theophylline, ciprofloxacin, fluvoxamine) CYP1A2 may increase or decrease, respectively, the metabolism of clozapine. For example, the induction of metabolism caused by smoking means that smokers require up to double the dose of clozapine compared with non-smokers to achieve an equivalent plasma concentration.Clozapine and norclozapine (desmethyl-clozapine) plasma levels may also be monitored, though they show a significant degree of variation and are higher in women and increase with age. Monitoring of plasma levels of clozapine and norclozapine has been shown to be useful in assessment of compliance, metabolic status, prevention of toxicity, and in dose optimisation.

Society and culture
Economics
Despite the expense of the risk monitoring and management systems required, clozapine use is highly cost effective; with a number of studies suggesting savings of tens of thousands of dollars per patient per year compared to other antipsychotics as well as advantages regarding improvements in quality of life. Clozapine is available as a generic medication.

Clozapine in the arts
Carrie Mathison, a fictional CIA operative in the television series Homeland secretly takes clozapine supplied by her sister for the treatment of bipolar disorder.
In the film Out of Darkness, Diana Ross played the protagonist Paulie Cooper, "a paranoid schizophrenic" who is depicted as having a dramatic improvement on clozapine.
In the television series Last Man On Earth (2015) the character Melissa has a psychotic episode and returns home and starts acting how she did pre-pandemic. Her boyfriend Todd sees her take a medication in the morning and asks her what it is. All she will say is "Santas Penis" </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Nabumetone and can you explain it in depth? [/INST] Nabumetone is a nonsteroidal anti-inflammatory drug (NSAID) </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Oritavancin and can you explain it in depth? [/INST] Oritavancin, sold under the brand name Orbactiv among others, is a semisynthetic glycopeptide antibiotic medication for the treatment of serious Gram-positive bacterial infections. Its chemical structure  as a lipoglycopeptide  is similar to vancomycin.The U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have approved oritavancin for treatment of acute bacterial skin and skin structure infections.

In vitro activity
Oritavancin shares certain properties with other members of the glycopeptide class of antibiotics, which includes vancomycin, the current standard of care for serious Gram-positive infections in the United States and Europe. It possesses potent and rapid bactericidal activity in vitro against a broad spectrum of both resistant and susceptible Gram-positive bacteria, including Staphylococcus aureus, MRSA, enterococci, and streptococci.  Oritavancin was more active than either metronidazole or vancomycin against strains of Clostridium difficile tested.Oritavancin has potential use as a therapy for exposure to Bacillus anthracis, the Gram-positive bacterium that causes anthrax, having demonstrated efficacy in a mouse model both before and after exposure to the bacterium.oritavancin demonstrates in vitro activity against both the planktonic and biofilmstates of staphylococci associated with Prosthetic joint infection (PJI), albeit with increased minimum biofilm bactericidal concentration (MBBC) compared to Minimum inhibitory concentrations (MIC) values. Moreever oritavancin has demonstrated activity against in vitro to vancomycin-susceptible enterococci (VSE) and vancomycin-resistant enterococci (VRE) in both planktonic and biofilm states.

Mechanism
The 4-chlorobiphenylmethyl group disrupts the cell membrane of Gram-positive bacteria.
It also acts by inhibition of transglycosylation and inhibition of transpeptidation.

Synergism
Several antibiotics have been tested as partner drugs of oritavancin. Among these "companions" drugs, fosfomycin displayed (in vitro and in vivo) synergistic activity when administered together with oritavancin against VRE strains (both vanA and vanB).

Spectrum of Activity
Oritavancin is active against gram-positive aerobic bacteria such as enterococci, staphylococci, streptococci, and anaerobic bacteria such as Clostridium difficile , Clostridium perfringens , Peptostreptococcus spp </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Ketoprofen and can you explain it in depth? [/INST] Ketoprofen is one of the propionic acid class of nonsteroidal anti-inflammatory drugs (NSAID) with analgesic and antipyretic effects. It acts by inhibiting the bodys production of prostaglandin.
It was patented in 1967 and approved for medical use in 1980.

Medical uses
Ketoprofen is generally prescribed for arthritis-related inflammatory pains or severe toothaches that result in the inflammation of the gums.
Ketoprofen topical patches are being used for treatment of musculoskeletal pain.Ketoprofen can also be used for treatment of some pain, especially nerve pain such as sciatica, postherpetic neuralgia and referred pain for radiculopathy, in the form of a cream, ointment, liquid, spray, or gel, which may also contain ketamine and lidocaine, along with other agents which may be useful, such as cyclobenzaprine, amitriptyline, acyclovir, gabapentin, orphenadrine and other drugs used as NSAIDs or adjuvant, atypical or potentiators for pain treatment.
Trial is been going on for using this drug along with ibuprofen for management of lymphedema. Animal trial and some human trials has been shown significant improvement over placebo control. Dr Stanley G Rockson, of Stanford University is leading these researches.

Efficacy
A 2013 systematic review indicated "The efficacy of orally administered ketoprofen in relieving moderate-severe pain and improving functional status and general condition was significantly better than that of ibuprofen and/or diclofenac." A 2017 Cochrane systematic review investigating ketoprofen as a single-dose by mouth in acute, moderate-to-severe postoperative pain concluded that its efficacy is equivalent to drugs such as ibuprofen and diclofenac.There is evidence supporting topical ketoprofen for osteoarthritis but not other chronic musculoskeletal pain.

Adverse effects
In October 2020, the U.S. Food and Drug Administration (FDA) required the drug label to be updated for all nonsteroidal anti-inflammatory medications to describe the risk of kidney problems in fetuses that result in low amniotic fluid. They recommend avoiding NSAIDs in pregnant women at 20 weeks or later in pregnancy.

Mechanism
Ketoprofen undergoes metabolism in the liver via conjugation with glucuronic acid (glucuronidation) by UGT enzymes, hydroxylation of the benzoyl ring by the CYP3A4 and CYP2C9 enzymes, and reduction of its ketone moiety (a carbonyl functional group, i.e. with carbon-oxygen double bond) by carbonyl reducing enzymes (CREs).  Ketoprofen is used for its antipyretic, analgesic, and anti-inflammatory properties by inhibiting cyclooxygenase-1 and -2 (COX-1 and COX-2) enzymes reversibly, which decreases production of proinflammatory prostaglandin precursors.The patches have been shown to provide rapid and sustained delivery to underlying tissues without significantly increasing levels of drug concentration in the blood when compared to the traditional oral administration.

Chirality and biological activity
Ketoprofen has one stereogenic center in the side chain and hence exists as mirror-image twins. Majority of the profens are marketed as racemic mixtures.  For most of the NSAIDs the pharmacological activity reside in the (S)-enantiomers with their  (R)-enantiomer of virtually inactive. An interesting observation about most profens including ketoprofen is that they undergo unidirectional metabolic inversion, chiral inversion, of the (R)- acid to its (S)-mirror-image version with no other change in the molecule.

Available forms
Ketoprofen was available over-the-counter in the United States in the form of 12.5 mg coated tablets (Orudis KT and Actron), but this form has been discontinued. It is available by prescription capsules.
Ketoprofen is also available as a 2.5% gel for topical application, and it is also available as a patch for topical analgesia and anti-inflammatory action. However, the gel is not sold in the United States.
Brand names in Australia are Orudis and Oruvail. It is available in Japan in a transdermal patch Mohrus Tape, made by Hisamitsu Pharmaceutical.  It is available in the UK as Ketoflam and Oruvail, in Ireland as Fastum Gel, in Estonia as Keto, Ketonal, and Fastum Gel, in Finland as Ketorin, Keto, Ketomex, and Orudis; in France as Profénid, Bi-Profénid and Ketum; in Italy as Ketodol, Fastum Gel, Lasonil, Orudis and Oki; in Poland as Ketonal, Ketonal active, Ketolek, in Serbia, Slovenia and Croatia as Knavon and Ketonal; in Romania as Ketonal and Fastum Gel; in Mexico as Arthril; in Norway as Zon and Orudis; in Russia as ОКИ (OKI), Fastum Gel and Ketonal; in Spain as Actron and Fastum Gel; in Albania as Oki and Fastum Gel and in Venezuela as Ketoprofeno as an injectable solution of 100 mg and 150 mg capsules.
In some countries, the optically pure (S)-enantiomer (dexketoprofen) is available; its trometamol salt is said to be particularly rapidly reabsorbed from the gastrointestinal tract, having a rapid onset of effects.
The earliest report of therapeutic use in humans was in 1972.

Veterinary medicine
Ketoprofen is a common NSAID, antipyretic, and analgesic used in horses and other equines. It is most commonly used for musculoskeletal pain, joint problems, and soft tissue injury, as well as laminitis. It is also used to control fevers and prevent endotoxemia. It is also used as a mild painkiller in smaller animals, generally following surgical procedures.
In horses, it is given at a dose of 2.2 mg/kg/day </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Triamcinolone and can you explain it in depth? [/INST] Triamcinolone is a glucocorticoid used to treat certain skin diseases, allergies, and rheumatic disorders among others. It is also used to prevent worsening of asthma and COPD. It can be taken in various ways including by mouth, injection into a muscle, and inhalation.Common side effects with long-term use include osteoporosis, cataracts, thrush, and muscle weakness. Serious side effects may include psychosis, increased risk of infections, adrenal suppression, and bronchospasm. Use in pregnancy is generally safe. It works by decreasing inflammation and immune system activity.Triamcinolone was patented in 1956 and came into medical use in 1958. It is available as a generic medication. In 2019, it was the 107th most commonly prescribed medication in the United States, with more than 6 million prescriptions.

Medical uses
Triamcinolone is used to treat a number of different medical conditions, such as eczema, alopecia areata, lichen sclerosus, psoriasis, arthritis, allergies, ulcerative colitis, lupus, sympathetic ophthalmia, temporal arteritis, uveitis, ocular inflammation, keloids, urushiol-induced contact dermatitis, aphthous ulcers (usually as triamcinolone acetonide), central retinal vein occlusion,  visualization during vitrectomy and the prevention of asthma attacks.The derivative triamcinolone acetonide is the active ingredient in various topical skin preparations (cream, lotion, ointment, aerosol spray) designed to treat skin conditions such as rash, inflammation, redness, or intense itching due to eczema and dermatitis.

Contraindications
Contraindications for systemic triamcinolone are similar to those of other corticoids. They include systemic mycoses (fungal infections) and parasitic diseases, as well as eight weeks before and two weeks after application of live vaccines. For long-term treatment, the drug is also contraindicated in people with peptic ulcers, severe osteoporosis, severe myopathy, certain viral infections, glaucoma, and metastasizing tumours.There are no contraindications for use in emergency medicine.

Side effects
Side effects of triamcinolone are similar to other corticoids. In short-term treatment up to ten days, it has very few adverse effects; however, sometimes gastrointestinal bleeding is seen, as well as acute infections (mainly viral) and impaired glucose tolerance.Side effects of triamcinolone long-term treatment may include coughing (up to bronchospasms), sinusitis, metabolic syndrome–like symptoms such as high blood sugar and cholesterol, weight gain due to water retention, and electrolyte imbalance, as well as cataract, thrush, osteoporosis, reduced muscle mass, and psychosis. Triamcinolone injections can cause bruising and joint swelling. Symptoms of an allergic reaction include rash, itch, swelling, severe dizziness, trouble breathing, and anaphylaxis.

Overdose
No acute overdosing of triamcinolone has been described.

Interactions
Drug interactions are mainly pharmacodynamic, that is, they result from other drugs either adding to triamcinolones corticoid side effects or working against its desired effects. They include:
Atropine and other anticholinergics can substantially increase pressure in the eyes.
Antidiabetic drugs can become less effective because triamcinolone causes diabetes-like symptoms.
Aspirin and other NSAIDs, as well as anticoagulants such as warfarin, add to the risk of gastrointestinal bleeding.
Diuretics that excrete potassium (such as loop diuretics and thiazides) can increase the risk of hypokalemia and thus lead to abnormal heart rhythm.
Cardiac glycosides may have more adverse effects due to reduced potassium levels in the blood.
The risk for blood count changes is increased when combining triamcinolone with ACE inhibitors.Triamcinolone and other drugs can also influence each others concentrations in the body, amounting to pharmacokinetic interactions such as:
Rifampicin, phenytoin, carbamazepine and other inducers of the liver enzyme CYP3A4 speed up metabolization of triamcinolone and can therefore reduce its effectiveness.
Conversely, CYP3A4 inhibitors such as ketoconazole and itraconazole can increase its concentrations in the body and the risk for adverse effects.
Blood concentrations of ciclosporin can be increased.

Pharmacology
Mechanism of action
Triamcinolone is a glucocorticoid that is about five times as potent as cortisol, but has very little mineralocorticoid effects.

Pharmacokinetics
When taken by mouth, the drugs bioavailability is over 90%. It reaches highest concentrations in the blood plasma after one to two hours and is bound to plasma proteins to about 80%. The biological half-life from the plasma is 200 to 300 minutes; due to stable complexes of triamcinolone and its receptor in the intracellular fluid, the total half-life is significantly longer at about 36 hours.A small fraction of the substance is metabolized to 6-hydroxy- and 20-dihydro-triamcinolone; most of it probably undergoes glucuronidation, and a smaller part sulfation. Three quarters are excreted via the urine, and the rest via the faeces.Due to corticoids mechanism of action, the effects are delayed as compared to plasma concentrations. Depending on the route of administration and the treated condition, the onset of action can be from two hours up to one or two days after application; and the drug can act much longer than its elimination half-life would suggest.

Chemistry
Triamcinolone is a synthetic pregnane corticosteroid and derivative of cortisol (hydrocortisone) and is also known as 1-dehydro-9α-fluoro-16α-hydroxyhydrocortisone or 9α-fluoro-16α-hydroxyprednisolone as well as 9α-fluoro-11β,16α,17α,21-tetrahydroxypregna-1,4-diene-3,20-dione.The substance is a light-sensitive, white to off-white, crystalline powder, or has the form of colourless, matted crystals. It has no odour or is nearly odourless </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Natamycin and can you explain it in depth? [/INST] Natamycin, also known as pimaricin, is an antifungal medication used to treat fungal infections around the eye. This includes infections of the eyelids, conjunctiva, and cornea. It is used as eyedrops. Natamycin is also used in the food industry as a preservative.Allergic reactions may occur. It is unclear if medical use during pregnancy or breastfeeding is safe. It is in the macrolide and polyene families of medications. It results in fungal death by altering the cell membrane.Natamycin was discovered in 1955 and approved for medical use in the United States in 1978. It is on the World Health Organizations List of Essential Medicines.  It is produced by fermentation of certain types of the bacterium Streptomyces.

Uses
Medical
Natamycin is used to treat fungal infections, including Candida, Aspergillus, Cephalosporium, Fusarium, and Penicillium. It is applied topically as a cream, in eye drops, or (for oral infections) in a lozenge. Natamycin shows negligible absorption into the body when administered in these ways. When taken orally, little or none is absorbed from the gastrointestinal tract, making it inappropriate for systemic infections. Natamycin lozenges are also prescribed to treat yeast infections and oral thrush.

Food
Natamycin has been used for decades in the food industry as a hurdle to fungal outgrowth in dairy products and other foods.  Potential advantages for the usage of natamycin might include the replacement of traditional chemical preservatives, a neutral flavor impact, and less dependence on pH for efficacy, as is common with chemical preservatives.  It can be applied in a variety of ways: as an aqueous suspension (such as mixed into a brine) sprayed on the product or into which the product is dipped, or in powdered form (along with an anticaking agent such as cellulose) sprinkled on or mixed into the product.
While not currently approved for use on meats in the United States, some countries allow natamycin to be applied to the surface of dry and fermented sausages to prevent mold growth on the casing.  Also, natamycin is approved for various dairy applications in the United States.  More specifically, natamycin is commonly used in products such as cream cheeses, cottage cheese, sour cream, yogurt, shredded cheeses, cheese slices, and packaged salad mixes. One of the reasons for food producers to use natamycin is to replace the artificial preservative sorbic acid.As a food additive, it has E number E235. Throughout the European Union, it is approved only as a surface preservative for certain cheese and dried sausage products. It must not be detectable 5 mm below the rind. While natamycin is approved in different applications at different levels in the world, it is approved in over 150 countries worldwide.The European Food Safety Authority (EFSA) panel took over the responsibilities of providing scientific food safety advice to the EU from the Scientific Committee on Food  in 2002.  In 2009, the EFSA considered the proposed use levels of natamycin are safe if it is used for the surface treatment for these cheese and sausage types.

Safety
Natamycin does not have acute toxicity. In animal studies, the lowest LD50 found was 2.5-4.5 g/kg. In rats, the LD50 is ≥2300 mg/kg, and doses of 500 mg/kg/day over 2 years caused no detectable differences in survival rate, growth, or incidence of tumors. The metabolites of natamycin also lack toxicity. The breakdown products of natamycin under various storage conditions may have a lower LD50 than natamycin, but in all cases, the numbers are quite high. In humans, a dose of 500 mg/kg/day repeated over multiple days caused nausea, vomiting, and diarrhea.No evidence shows natamycin, at either pharmacological levels or levels encountered as a food additive, can harm normal intestinal flora, but definitive research may not be available. However, some people are allergic to natamycin.The EFSA has concluded that the use of natamycin as a food additive has no relevant risk for the development of resistant fungi.

Mechanism of action
Natamycin inhibits the growth of fungi by specifically binding to ergosterol present in fungal cell membranes. Natamycin inhibits amino acid and glucose transport proteins leading to a loss of nutrient transport across the plasma membrane. While this binding is reversible, ergosterol binding acts as a universal mechanism of fungal inhibition, allowing natamycin to act on diverse fungal pathogens from Saccharomyces yeast to Aspergillus moulds. Natamycin is unique amongst related antifungals specifically because it does not directly cause membrane permeabilization. Structurally-related antibiotics with similar binding properties are thought to produce hydrophilic channels that allow leakage of potassium and sodium ions from the cell.Natamycin has very low solubility in water; however, natamycin is effective at very low levels. Its minimum inhibitory concentration is less than 10 ppm for most molds.

Biochemistry
Natamycin is produced as a secondary metabolite by some Streptomyces species: S. natalensis, S. lydicus, S. chattanoogensis and S </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Voretigene neparvovec and can you explain it in depth? [/INST] Voretigene neparvovec, sold under the brand name Luxturna, is a gene therapy medication for the treatment of Leber congenital amaurosis. It was developed by Spark Therapeutics and Childrens Hospital of Philadelphia. It is the first in vivo gene therapy approved by the US Food and Drug Administration (FDA).Lebers congenital amaurosis, or biallelic RPE65-mediated inherited retinal disease, is an inherited disorder causing progressive blindness. Voretigene is the first treatment available for this condition. The gene therapy is not a cure for the condition, but substantially improves vision in those treated. It is given as a subretinal injection.
Voretigene neparvovec was approved for medical use in Australia in August 2020 and in Canada, in October 2020.

Medical uses
Voretigene neparvovec is indicated for the treatment of people with vision loss due to inherited retinal dystrophy caused by confirmed biallelic RPE65 mutations and who have sufficient viable retinal cells.

Chemistry and production
Voretigene neparvovec is an AAV2 vector containing human RPE65 cDNA with a modified Kozak sequence </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Lefamulin and can you explain it in depth? [/INST]  </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Eptifibatide and can you explain it in depth? [/INST] Eptifibatide (Integrilin, Millennium Pharmaceuticals, also co-promoted by Schering-Plough/Essex), is an antiplatelet drug of the glycoprotein IIb/IIIa inhibitor class. Eptifibatide is a cyclic heptapeptide derived from a disintegrin protein (P22827) found in the venom of the southeastern pygmy rattlesnake (Sistrurus miliarius barbouri). It belongs to the class of the arginin-glycin-aspartat-mimetics and reversibly binds to platelets. Eptifibatide has a short half-life. The drug is the third inhibitor of GPIIb/IIIa that has found broad acceptance after the specific antibody abciximab and the non-peptide tirofiban entered the global market.

Indications
Eptifibatide is used to reduce the risk of acute cardiac ischemic events (death and/or myocardial infarction) in patients with unstable angina or non-ST-segment-elevation (e.g., non-Q-wave) myocardial infarction (i.e., non-ST-segment elevation acute coronary syndromes) both in patients who are to receive non surgery (conservative) medical treatment and those undergoing percutaneous coronary intervention (PCI).
The drug is usually applied together with aspirin or clopidogrel and (low molecular weight or unfractionated) heparin. Additionally, the usual supportive treatment consisting of applications of nitrates, beta-blockers, opioid analgesics and/or benzodiazepines should be employed as indicated. Angiographic evaluation and other intensive diagnostic procedures may be considered a first line task before initiating therapy with eptifibatide.
The drug should exclusively be used in hospitalized patients both because of the serious degree of patients illness and because of the possible side-effects of eptifibatide.

Contraindications and precautions
Thrombocytopenia : The drug is contraindicated in patients with platelet counts of less than 100,000 per μl because no clinical experience exists regarding such patients.
Chronic kidney disease : Eptifibatide undergoes kidney elimination. In such patients with chronic kidney disease where a glycoprotein IIb/IIIa inhibitor is likely to provide benefit, Abciximab (trade name: Reopro) is an alternative medication.
Current bleeding tendencies or abnormally prolonged coagulation parameters observed within 30 days before starting therapy with eptifibatide is intended.
Coagulation parameters such as ACT, aPTT, TT, and PT should be followed closely during therapy and afterwards.
Allergy to eptifibatide and/or other ingredients.
Severe, uncontrolled hypertension.
Pregnancy : No experience exists. Pregnant patients should be treated only when clearly needed.
Lactation : No human data exists. Breast-feeding should be avoided during treatment in order to prevent damage to the newborn.
Geriatric patients : No differences in side effects compared with younger patients have been seen. Nevertheless, geriatric patients should be very closely observed for bleeding and other side-effects.
Pediatric patients : Eptifibatide is not indicated in patients below 18 years of age, because no experience exists.

Side effects
People receiving eptifibatide are typically seriously ill and most of them are concomitantly treated with other drugs known to have the potential to cause significant side effects. Therefore, not all side effects listed as follows may be attributable to eptifibatide treatment alone:
The major adverse event in the PURSUIT study was severe bleeding. Bleeding occurred as well at sites of clinical intervention (local sites) as at other sites (systemically) like urogenital bleeds. Sometimes, these events were severe enough to require transfusion of blood or plasma concentrates to stop bleeding and counteract anemia. Severe bleeds occurred in 4.4 and 4.7% of patients respectively depending on the infusion rate (0.5 µg/kg/min vs. 0.75 µg/kg/min). A few cases of death due to severe bleeding events attributable to drug therapy were reported. No cases of hemorrhagic stroke were seen. Thrombocytopenia of unknown origin (allergic reaction?) was also noticed in 0.2% of patients.
Additionally, hypotension was seen frequently (6%). Cardiovascular failure was also frequent (2%) as were serious arrhythmias (ventricular fibrillation 1.5%, atrial fibrillation 6%). Severe allergic (anaphylactic) reactions occurred in almost 0.2% of patients. These reactions can be life-threatening and may be due to the peptide character of eptifibatide. Other side effects were rare and mild in nature and may not be connected to eptifibatide therapy.

Study results
Eptifibatide was licensed due to the positive results of the so-called PURSUIT study encompassing 10,948 patients. In this study all patients had experienced either unstable angina or a non-ST-segment-elevation myocardial infarction. Significantly fewer patients developed a myocardial infarction under therapy with eptifibatide </s>