Cimetidine: clinical uses and possible side effects.

Cimetidine has now been on the market for over three years and appears to be safe and effective. Its beneficial effect in the short-term treatment of peptic ulcer disease in the duodenum is well documented, and it appears to be helpful in preventing ulcer relapse. It may also be therapeutic in other diseases associated with gastric acid abnormalities. Cimetidine may cause mental confusion and should be used with caution and in reduced dosage in the presence of hepatic or renal disease, or both, and in elderly patients. Other potential problems include neutropenia, reduced sperm count, and potentiation of warfarin.