Objectives: a) To determine whether enteral ranitidine in intensive care unit (ICU) patients would produce serum levels that would reduce stimulated gastric acid by > or = 50%, and b) to evaluate the differences in cost between enteral and parenteral administration of ranitidine.
Design: Prospective, nonrandomized clinical trial.
Setting: A surgical ICU in a public primary teaching hospital for a medical school.
Patients: Postoperative or posttraumatic surgical patients who met one or more main criteria for stress.
Interventions: Two groups of patients were given ranitidine through a nasogastric tube. Group 1 (n = 10) received 150 mg every 12 hrs, and group 2 (n = 8) received 300 mg every 12 hrs.
Measurements and main results: Serum samples for measurement of ranitidine concentrations were collected at 2, 6, and 12 hrs after the fifth dose of oral ranitidine. Patients were monitored for upper gastrointestinal bleeding. All patients had therapeutic serum ranitidine concentrations at 2 and 6 hrs, while 88% of patients had therapeutic levels at 12 hrs.
Conclusions: a) Enteral administration of ranitidine every 12 hrs leads to effective absorption of the drug from the upper gastrointestinal tract of ICU patients. b) Serum concentrations of ranitidine for both 150-mg and 300-mg enteral doses remained within, or exceeded, the therapeutic range in > 90% of ICU patients with clinically important criteria of stress.