A randomized clinical trial comparing ranitidine and antacids in critically ill patients.

In a randomized trial of gastric pH control for stress ulcer prophylaxis, 200 mg/day ranitidine iv was compared to antacids in 86 patients admitted to an ICU. Six (15%) patients receiving ranitidine and six (13%) given antacids failed to maintain greater than 50% of the hourly gastric pH measurements at or above 4. Increasing the ranitidine dosage to 300 mg/day did not provide additional control. One patient in the antacid group developed an overt upper GI bleed secondary to endoscopically proven erosive disease. We conclude that iv ranitidine in a dosage of 200 mg/day is as effective as antacids in reducing gastric acidity and preventing stress ulcer disease in critically ill patients.