Detailed Drug Information:

DRUG CLASS AND MECHANISM: Histamine is a natural chemical thatstimulates stomach cells to produce acid. Cimetidine belongs to a class ofmedications called H2-blockers that inhibit the action of histamine on thestomach cells, thus reducing stomach acid production.

PRESCRIPTION: available with or without a prescription

PREPARATIONS: Tablets: 100 mg, 200 mg, 300 mg, 400 mg, 800 mg.Liquid: 300 mg per 5 ml teaspoon

STORAGE: Should be stored at room temperature in tightly closedcontainer.

PRESCRIBED FOR: Cimetidine blocks the action of histamine onstomach cells and reduces stomach acid production. Cimetidine is useful inpromoting the healing of active stomach and duodenal ulcers, and inreducing ulcer pain. Cimetidine has been effective in preventing ulcerrecurrence when given in low doses for prolonged periods of time. In doseshigher than that used in ulcer treatment, cimetidine has been helpful intreating heartburn and in healing ulcer and inflammation of the esophagusresulting from acid reflux (reflux esophagitis).

DOSING: May be taken with or without food.

DRUG INTERACTIONS: Antacids may decrease the absorption ofcimetidine. Cimetidine may interact with warfarin (Coumadin), a commonlyused blood thinning agent. Patients taking both medications should havefrequent blood monitoring to avoid accumulation of high levels of Coumadin, leading to excessive blood thinning and bleeding. Cimetidine canalso change blood levels of other medications such as phenytoin (Dilantin), used in seizure prevention, theophylline, used in asthma,lidocaine, used in treating fast heart rhythms, or metronidazole, used inmany infections. Safe use in children has not been established. Cimetidineis not habit forming.

SIDE EFFECTS: Side effects are rare and generally reversibleonce the medication is stopped. Minor side effects include constipation,diarrhea, fatigue, headache, insomnia, muscle pain, nausea, and vomiting.Major side effects include confusion and hallucinations (usually inelderly or critically ill patients), and enlargement of the breasts andimpotence (usually seen in patients on high doses for prolonged periods). Other rare side effects include irregular heartbeat, impotence, rash,visual changes, and yellowing of the skin or eyes.