• We examined the effect of cimetidine in altering gastric microflora in patients undergoing gastric resection for peptic ulcer disease. Ten patients had administration of cimetidine stopped at least six hours before surgery. Their mean gastric pH was 2.02 ± 1.51, and 0.4±0.97 organisms were isolated per patient. Ten patients were maintained on a regimen of cimetidine and their mean gastric pH was 5.69±1.80, with 3.2±1.62 organisms isolated per patient. We reached the following conclusions: cimetidine alters the gastric pH of preoperative patients; cimetidine therapy is associated with an increase in gastric flora; stopping administration of cimetidine six hours before surgery reacidifies the stomach, decreases the number of organisms isolated from the stomach, and decreases the risk of septic complications.
(Arch Surg 1983;118:1413-1415)