The role of acid suppressants in upper gastrointestinal ulcer bleeding.

Re-bleeding and mortality remain significant in peptic ulcer haemorrhage despite the widespread use of endoscopic therapy. The acidic gastric environment interferes with coagulation. In vitro studies show that an intragastric pH of above 6 results in normal blood coagulation and platelet function. Because of induced tachyphylaxis, H(2)-receptor antagonists are not able to maintain a high pH. In addition, in randomized trials using H(2)-receptor antagonists, there was no reduction in re-bleeding and mortality. High-dose intravenous proton pump inhibitors are capable of maintaining a pH above 6. Four randomized trials, using high-dose intravenous proton pump inhibitors, significantly improved the outcome (in terms of a reduction in re-bleeding and surgery) in patients with peptic ulcer haemorrhage. Mortality was, however, not reduced. The additional effect of acid-suppressant agents after successful endoscopic therapy is limited to the reduction of re-bleeding and need for surgery, with no effect on mortality.