Maintenance of gastric pH above 6 with intravenous famotidine in patients with a bleeding duodenal ulcer

Background: The secondary prevention of bleeding from ulcers may be improved if antisecretory drugs are able to maintain a 24-h gastric pH close to neutral. Aim: To evaluate the effect of intravenous famotidine at a conventional dose of 40 mg/day on 24-h intragastric pH in patients with a bleeding duodenal ulcer, and to determine the dose required to maintain gastric pH > 6 by use of a Gastrojet (MIC, Switzerland) device (a pH meter-controlled programmable pump). Methods: Twelve patients (nine men, three women), aged 24–78 years, admitted for a bleeding duodenal ulcer, were studied after active bleeding had stopped for at least 6 h. Gastric pH was recorded for two consecutive 24-h periods, each starting at 16.00 hours. The patients were fasted during these periods and received an infusion of 2.5 L of isotonic glucose. They were given famotidine, as a continuous i.v. infusion of 40 mg during one period, and at a rate determined by the Gastrojet during the other period (in a random sequence), with the aim of maintaining the gastric pH above 6. Results: The 24-h median (interquartile range) pH and the mean (± S.E.M.) percentage of the 24-h period with a gastric pH > 6 were both significantly higher during the Gastrojet period than during the continuous infusion: 6.4 (6.3–6.5) vs. 5.7 (2.7–6.4) (P < 0.01) and 74±5% vs. 44 ± 7% (P < 0.002), respectively. The mean dose of famotidine delivered by the Gastrojet was 172 mg (range: 101–200 mg). The entire available amount of famotidine (200 mg) was delivered in four of the 12 patients. The percentage of time at pH > 6 (mean ± S.E.M.) was significantly higher at night (22.00 to 07.00 hours) than during the rest of the day (88 ± 2 vs. 70 ± 6%; P < 0.005) and the mean quantity of famotidine delivered per hour was significantly lower during the night (6.3 ± 0.8 mg/h vs. 8.4 ± 0.5 mg/h; P < 0.02). Conclusion: We conclude that 40 mg of famotidine delivered as a continuous i.v. infusion is not sufficient to maintain gastric pH > 6 for 24 h in duodenal ulcer patients. Our study with the Gastrojet device shows that it may be possible to achieve this goal by using a much larger dose, preferably delivered during the day.