[Comparative study of famotidine vs ranitidine in critically ill patients in mechanical ventilation].

Stress ulcers are frequent in critically ill patients. Gastric mucosa protection with antacids, H2 blockers or sucralphate decrease the incidence of stress ulcers and upper gastrointestinal bleeding but may have adverse effects. The present study compares the efficacy of continuous infusions of famotidine on gastric pH control and bleeding prevention in critically ill patients receiving mechanical ventilation. Fifty six patients (aged 55 +/- 22 years, 26 male) were randomly assigned to receive famotidine 40 mg/day (n = 27) or ranitidine 150 mg/day (n = 29) during 5 days. Gastric pH was measured every 6 hours and when it was below 5, aluminum hydroxide (30 ml every 2 hours) was administered to obtain values over 5. Patients receiving famotidine had higher mean gastric pH (6.3 +/- 0.2 and 93% of measurements over 5 vs 5.8 +/- 0.6 and 83% of measurements over 5 (p < 0.05), and required lower amounts of aluminum hydroxide (1.880 vs 2.770 ml). No patient had evidence of gastrointestinal bleeding and one had a mild psychomotor agitation. No other adverse reactions were observed. It is concluded that famotidine was more effective than ranitidine on gastric pH control in mechanically ventilated critically ill patients.