For which condition is cimetidine primarily prescribed?

Cimetidine is primarily prescribed for the treatment of conditions associated with excess stomach acid, particularly peptic ulcers and gastroesophageal reflux disease (GERD). One of its significant uses is in the eradication of Helicobacter pylori (H. pylori), a bacterium that is a common cause of gastric ulcers. By reducing stomach acid production, cimetidine creates an environment that is less conducive to H. pylori, allowing for better efficacy of antibiotics used during combination therapy to eliminate the infection.

Conditions like cystic fibrosis predominantly involve pulmonary complications and require different therapies other than acid suppression. Clostridium difficile is an infection associated with antibiotic use, and treatment focuses on antibiotics rather than acid-reducing medications. Crohn's disease involves inflammation of the gastrointestinal tract, which usually requires a different category of medications such as corticosteroids or immunosuppressants rather than a histamine H2-receptor antagonist like cimetidine.