The active ingredient famotidine belongs to the H2 antihistamines. It is used to treat stomach disorders and decreases the secretion of stomach acid.
What is famotidine?
Famotidine is an H2 antihistamine. It is offered in Germany in the form of film-coated tablets and is in circulation as a generic from various suppliers. Famotidine can be used to control gastric acid production as part of gastric ulcer prophylaxis. The drug is also suitable for the treatment of reflux disease. Together with drugs that belong to the antacids, famotidine also helps against acid regurgitation and heartburn.
Pharmacologic action
The active ingredient famotidine is used for the treatment of stomach diseases and decreases the secretion of stomach acid. Famotidine is an H2 receptor blocker. These active substances have the property of reducing excessive production of gastric acid. In this way, pain can be effectively relieved in both gastric ulcers and duodenal ulcers. In addition, famotidine has a positive effect on the healing process of the ulcer. In medicine, famotidine is considered one of the most efficient drugs of its kind. Even in small doses, the antihistamine can counteract the activity of gastric plaque cells. Stomach acid (hydrochloric acid) is produced by these cells. Thus, famotidine is able to slow down the production of gastric juice, reducing unwanted irritation of ulcers. The bioavailability of famotidine ranges from 20 to 68 percent. Within the blood, an average of 20 percent of the drug is bound to plasma proteins. About 30 percent of the drug is metabolized by the kidneys. The plasma half-life usually reaches three hours.
Medical application and use
Famotidine is used for the treatment of benign gastric ulcers (ulcera ventriculi) and duodenal ulcers (ulcera duodeni). Another indication is the so-called Zollinger-Ellison syndrome. In this disease, ulcers form in the stomach, duodenum, and jejunum. Also in this condition the production of gastric acid increases pathologically. With other medications, famotidine can also be used to treat heartburn as well as acid regurgitation. Famotidine is administered in the form of film-coated tablets. The dosage of the drug depends on the type of disease. For example, in benign gastric ulcers or acute duodenal ulcers, two film-coated tablets of 20 grams per day are taken in the evening hours. Alternatively, administration of one 40-milligram tablet per day is also possible. In Zollinger-Ellison syndrome, the patient receives one 20-mg film-coated tablet every six hours, provided there has been no prior treatment with anti-secretory preparations. The extent of gastric acid secretion and the patient’s clinical response to the drug play an important role in dosage. Sometimes daily doses of up to 800 milligrams can be taken with famotidine over a period of one year without increased side effects. Because famotidine is largely excreted by the kidneys, patients with impaired kidney function should not take more than 20 milligrams of the antihistamine. The same applies to dialysis patients. In the case of gastric and duodenal ulcers, the recommended duration of therapy is four to eight weeks. In Zollinger-Ellison syndrome, treatment is continued as long as medically deemed necessary.
Risks and side effects
Adverse side effects may be experienced as a result of famotidine administration. However, they do not occur in everyone. Most patients experience constipation, diarrhea, headache, or dizziness. Occasionally, rashes on the skin, fatigue, nausea, and vomiting may also occur. In rare cases, joint pain, itching, pronounced skin reactions, hair loss, confusion, depression, loss of libido, erectile dysfunction, as well as hallucinations are in the range of possibility. If the patient suffers from hypersensitivity to famotidine or any other H2 receptor blocker, the drug should not be taken. There is otherwise a risk of cross-allergy. People with impaired kidney and liver function should refrain from taking the drug in high doses for prolonged periods.Children under 16 years of age are generally not advised to use famotidine for heartburn or gastric acidity because there is insufficient information about possible side effects in their age group. Use of famotidine during pregnancy should only occur after the treating physician has thoroughly weighed the risks and benefits. Famotidine also has the property of passing into breast milk. For this reason, disturbances of gastric acid production in the child are conceivable. Interfering interactions may occur due to the intake of famotidine and other drugs at the same time. For example, the absorption of the antifungal agents itraconazole and ketoconazole into the bloodstream is reduced. In contrast, the effect of erythromycin, which is an antibiotic, is increased. If famotidine is taken in parallel with an acid-binding agent such as sucralfate, this leads to reduced absorption of the H2 antihistamine. In turn, the combination with the gout suppressant probenecid causes the excretion of famotidine to proceed more slowly.
