Safety and acid-suppressant properties of histamine2-receptor antagonists for the prevention of stress-related mucosal damage in critical care patients.

Therapeutic intervention for the prevention of stress-related mucosal damage (SRMD) is currently directed at decreasing mucosal exposure to endogenous hydrochloric acid. We conducted a double-blind, parallel-group study in critically ill patients to investigate the comparative safety and acid-suppressant properties of the intravenously administered H2-receptor antagonists cimetidine and famotidine. This is a preliminary analysis. Study patients received either famotidine 20 mg q12h or cimetidine 300 mg q6h or q12h. Cimetidine dosing intervals were based upon the degree of renal and hepatic dysfunction due to pharmacokinetic considerations. In critically ill patients with severe renal impairment, a pH of greater than or equal to 4.0 was maintained more consistently with famotidine 20 mg q12h compared with treatment with cimetidine. In terms of safety, a greater number of patients receiving cimetidine reported adverse clinical experiences than those receiving famotidine and a greater number of cimetidine patients had to be withdrawn from the study when compared with famotidine patients. In conclusion, preliminary results of this study suggest that famotidine has superior acid-suppressant properties and a better safety profile when used intravenously for the prevention of SRMD in critically ill patients.