The effectiveness of gastric pH control with bolus famotidine versus cimetidine for stress ulcer prophylaxis in a surgical intensive care unit

Our study examined the effectiveness of a potent histamine₂-receptor antagonist, famotidine, in gastric pH control, compared with that of cimetidine, using intermittent bolus administrative for stress ulcer prophylaxis. A total of 48 patients who were admitted into the general surgery intensive care unit for a minimum of 3 days and who required mechanical ventilation were included in the study. Each patient participated in three different regimens (cimetidine 200 mg every 4 hours, cimetidine 400 mg every 4 hours, and famotidine 20 mg every 8 hours, in six randomized sequences) on 3 consecutive days. Intragastric pH was measured by use of a continuous pH-monitoring system. Median gastric pH, the percentage of time pH was >4, and the frequency distribution of gastric pH values during the treatment period were measured. No significant improvements in gastric pH were measured and percentage of time that pH was >4 occurred when the patients received cimetidine 400 mg every 4 hours, compared with cimetidine 200 mg every 4 hours (P = 0.49 and 0.17, respectively). Gastric pH and percentage of time pH was >4 were significantly better when patients received famotidine 20 mg every 8 hours, as compared with both the cimetidine 200-mg and cimetidine 400-mg regimens (gastric pH: P = 0.0009 for the 200-mg dose and P = 0.019 for the 400-mg dose; percentage of time pH was >4: P < 0.0001 for the 200-mg dose and P = 0.019 for the 400-mg dose). The effective duration of action (percentage of time pH was >4) for each dose regimen was: cimetidine 200 mg, 1.4 hours; cimetidine 400 mg, 1.8 hours; and famotidine 20 mg, 4.8 hours. The bolus regimen of famotidine achieved a more effective and consistent pH control than the cimetidine regimens for stress ulcer prophylaxis in critically ill patients. It also required less-frequent injections than cimetidine, thus reducing nursing demand; however, in high-risk patients or those with active stress ulcer bleeding, a 6-hour dose schedule may afford better control.