Problems associated with medical treatment of peptic ulcer disease.

In the United States, the drugs most commonly used to treat peptic ulcer disease are antacids and the H2-receptor antagonists cimetidine and ranitidine. Other available agents include anticholinergics and the coating agent sucralfate. Investigational drugs such as colloidal bismuth, carbenoxolone, prostaglandins, the tricyclic compound pirenzepine, and substituted benzimidazoles are not available for use in the United States. Most of the commercially available and investigational compounds have similar efficacy; therefore the optimal drug may be the one associated with the fewest adverse effects and the most convenient dosing regimen. Cimetidine causes a small number of adverse effects, including neuropsychiatric disorders, gynecomastia, impotence, loss of libido, elevation of serum creatinine and serum transaminases concentrations, and drug interactions. Some of these reactions have been of clinical significance. Presently, there are rare reports of gynecomastia, bradycardia, inhibition of acetylcholinesterase, headache, lethargy, diarrhea, and rash in patients receiving ranitidine. Antacids can produce either diarrhea or constipation and have been associated with low serum phosphorus concentrations, and metabolic alkalosis. Anticholinergics, especially in elderly or debilitated patients, can cause central nervous system disorders, intestinal atony, or urinary retention. Sucralfate may cause constipation, diarrhea, nausea, and headache. The investigational agents have their own side effect profiles. The adverse effects of anticholinergics make them unattractive therapeutic choices, and antacids and sucralfate have inconvenient dosing requirements compared with some equally efficacious alternatives. In addition, clinical experience with sucralfate in the United States is limited. The safety record of cimetidine is admirable. As clinical experience with ranitidine increases, currently unrecognized adverse effects may be reported. However, based on current data, ranitidine is as effective as cimetidine and is associated with a lower incidence of side effects.