Cimetidine

Cimetidine, sold under the brand name Tagamet among others, is a histamine H2 receptor antagonist that inhibits stomach acid production. It is mainly used in the treatment of heartburn and peptic ulcers. While, in the United Kingdom there is an exception to the POM category where for the short-term symptomatic relief of heartburn, dyspepsia, and hyperacidity. Cimetidine, sold under the brand name Tagamet among others, is a histamine H2 receptor antagonist that inhibits stomach acid production. It is mainly used in the treatment of heartburn and peptic ulcers. While, in the United Kingdom there is an exception to the POM category where for the short-term symptomatic relief of heartburn, dyspepsia, and hyperacidity. The development of longer-acting H2 receptor antagonists with fewer drug interactions and adverse effects, such as ranitidine and famotidine, decreased the use of cimetidine, and though it is still used, cimetidine is no longer among the more widely used of the H2 receptor antagonists. Cimetidine was discovered in 1971 and came into commercial use in 1977. Cimetidine was approved in the United Kingdom in 1976, and was approved in the United States by the Food and Drug Administration for prescriptions in 1979. Cimetidine is used to inhibit stomach acid production and is used in the treatment of heartburn and peptic ulcers. Some evidence suggests cimetidine could be effective in the treatment of common warts, but more rigorous double-blind clinical trials found it to be no more effective than a placebo. Tentative evidence supports a beneficial role as add-on therapy in colorectal cancer. Cimetidine inhibits ALA synthase activity and hence may have some therapeutic value in preventing and treating acute porphyria attacks. Reported side effects of cimetidine include diarrhea, rashes, dizziness, fatigue, constipation, and muscle pain, all of which are usually mild and transient. It has been reported that mental confusion may occur in the elderly. Because of its hormonal effects, cimetidine rarely may cause sexual dysfunction including loss of libido and erectile dysfunction and gynecomastia (0.1–0.2%) in males during long-term treatment. Rarely, interstitial nephritis, urticaria, and angioedema have been reported with cimetidine treatment. Cimetidine is also commonly associated with transient raised aminotransferase activity; hepatotoxicity is rare. Cimetidine appears to be very safe in overdose, producing no symptoms even with massive overdoses (e.g., 20 g).