Dogs and cats are not like humans when it comes to drug metabolism. Although some human medications are used in veterinary medicine, the dosages are vastly different (especially in cats). When pet poisonings from human medications happen, they can be life threatening. Here are the top 10 human medications that are the most commonly seen:
NSAIDS (Ibuprofen, Naproxen)
One of the most common problems seen is toxicity from the common household medication called non-steroidal anti-inflammatories (NSAIDs), which include names such as ibuprofen (e.g., Advil and types of Motrin) and naproxen (e.g., Aleve). While these drugs are safe for people, just one tablet can be toxic for pets. Dogs, cats, birds, ferrets, gerbils and hamsters may develop serious stomach and intestinal ulcers as well as kidney failure.
Although safe for human children, acetaminophen (e.g., Tylenol) should not be given to pets, especially cats. One regular strength tablet of acetaminophen can affect red blood cells, damaging them so that they cannot carry oxygen. Acetaminophen can lead to liver failure in dogs, and with large doses can cause red blood cell damage.
Antidepressants (Effexor, Cymbalta, Prozac, Lexapro, etc.)
Although these drugs are occasionally used in pets in low doses, overdoses can lead to serious neurological problems such as sedation, incoordination, tremors and seizures. Some antidepressants also have a stimulant effect leading to a dangerously elevated heart rate, blood pressure and body temperature. Pets, especially cats, seem to like the taste of Effexor and may eat the entire pill or pills. Just one pill can cause serious poisoning.
ADD and ADHD Medications (e.g., Concerta, Adderall, Ritalin)
These and other medications used to treat attention deficit disorder and attention deficit hyperactivity disorder in people contain methylphenidate and amphetamines which are potent stimulants. These drugs can cause serious side effects including seizures, elevated body temperature, heart problems and life-threatening tremors.
Benzodiazepines and Sleep Aids (e.g., Xanax, Klonopin, Ambien, Lunesta)
Although these drugs are intended to reduce anxiety and help people sleep better, they often have the opposite effect in pets. About half of the dogs that ingest sleep aids become agitated instead of sedate. The other half show symptoms of severe lethargy, incoordination and respiratory depression (slowed breathing). Benzodiazepines can cause liver failure in cats when ingested.
Birth Control (e.g., Estrogen, Estradiol, Progesterone)
These appear to be a popular item with dogs, as they apparently like how birth control pills are packaged. Fortunately, if small amounts of these medications are ingested, they typically do not cause problems. However, the ingestion of large amounts of estrogen and estradiol can cause bone marrow suppression, especially in birds. Dogs and cats that have not been spayed are at an increased risk of side effects from estrogen poisoning.
ACE Inhibitors (e.g., Zestril, Altace)
These drugs are used to treat high-blood pressure in people, and occasionally pets. Overdoses usually cause low blood pressure, dizziness and weakness. Low doses, when ingested, may only cause mild symptoms. However, depending upon the dosage and if there is a history of kidney failure or heart disease, your pet may need to be hospitalized for observation and monitoring.
Beta-Blockers (e.g., Tenormin, Toprol, Coreg)
Beta-blockers are also used in people to treat high-blood pressure but, unlike ACE inhibitors, ingestion of this drug (even small amounts) may cause serious poisoning in pets. Symptoms of ingestion include life-threatening drop in blood pressure and a very slow heart rate.
Thyroid Hormones (e.g., Armour Desiccated Thyroid, Synthroid)
Dogs, like people, can have low thyroid levels and require supplementation. Surprisingly, the amount of thyroid medication needed in dogs is higher than in people. Therefore, accidental ingestion of small amounts of thyroid medication usually will not cause problems. However, large amounts of thyroid medication ingested in dogs and cats can cause muscle tremors, nervousness, panting, aggression and a rapid heart rate.