Hormones are substances that are normally produced and secreted by various glands in the body; they act to stimulate and regulate body functions. Hormone medications mimic the effects of naturally produced hormones and are commonly given when naturally occurring hormones are not being produced in sufficient amounts to regulate specific body functions. This category of medication also includes oral contraceptives (birth control pills) as well as certain types of medications that are used to combat inflammatory reactions.
Insulin, a hormone that is secreted by the pancreas, regulates the level of glucose (a form of sugar) in the blood, as well as the metabolism of carbohydrates and fats. Insulin's counterpart, glucagon, stimulates the liver to release stored glucose. Both insulin and glucagon must be present in the right amounts to maintain the proper blood sugar levels in the body.
Treatment of diabetes mellitus (inability of the body to produce and/or utilize insulin) may involve an adjustment of diet and/or the administration of insulin or oral antidiabetic drugs. Glucagon is given only in emergencies, such as insulin shock, when blood sugar levels must be raised quickly.
People with type 1, or insulin-dependent, diabetes must use insulin to control their blood sugar levels. People who have type 2, or non-insulin-dependent, diabetes may be able to regulate their blood sugar levels through diet modification alone. If not, they may be prescribed oral antidiabetic medications, such as glimepiride, metformin, acarbose, or rosiglitazone. Oral antidiabetics induce the pancreas to secrete more insulin by acting on small groups of pancreatic cells that make and store insulin. Some people with type 2 diabetes may need both insulin and oral antidiabetic drugs.
Although small amounts of sex hormones are secreted by the adrenal glands in both males and females, for the most part these hormones are produced by the sex glands. Estrogens and progesterone are the female hormones responsible for secondary sex characteristics such as development of the breasts and maintenance of the lining of the uterus. Testosterone (androgen) is the corresponding male hormone. It is responsible for secondary sex characteristics such as facial hair, a deepened voice, and the maturation of external genitalia.
Testosterone reduces elimination of protein from the body, thereby producing an increase in muscle size. Athletes sometimes take drugs called anabolic steroids (which are chemicals similar to testosterone) for this effect, but using medication for this purpose is dangerous, since anabolic steroids can adversely affect the heart, the nervous system, and the kidneys and cause long-term damage.
Most oral contraceptives (birth control pills) combine estrogen and progestin (natural or synthetic progesterone), but some contain only progestin. Examples of progestin-only contraceptives include the Norplant implant and the Depo-Provera contraceptive device. Progestin aids in preventing ovulation, alters the lining of the uterus, and thickens cervical mucus -- processes that help to prevent conception and implantation. The estrogen in birth control pills prevents egg production. Oral contraceptives have many side effects, so their use should be discussed with a physician.
Conjugated estrogens are occasionally used in hormone replacement therapy to treat more severe symptoms of menopause in women whose bodies are no longer able to produce estrogen in sufficient quantities. However, they are no longer recommended for long-term treatment or replacement therapy in most patients.
Medroxyprogesterone is used to treat uterine bleeding because of its ability to induce and maintain a lining in the uterus that resembles the lining produced during pregnancy. It also suppresses the release of the pituitary hormone that initiates ovulation, and it is used for menstrual problems.
The pituitary gland secretes adrenocorticotropic hormone (ACTH), which directs the adrenal glands to produce adrenocorticosteroids, such as cortisone. Oral steroid preparations (prednisone, for example) may be used to treat poison ivy, hay fever, or insect bites as well as inflammatory diseases such as arthritis, allergies, and asthma. How these drugs relieve inflammation is currently unknown.
In the past, thyroid preparations were made by drying and pulverizing the thyroid glands of animals and then forming them into tablets. That medication is in minimal use today because people who are unable to produce a sufficient amount of thyroid hormone are usually prescribed a synthetic form, such as levothyroxine.