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 im proved if antisecretory drugs are able to maintain a 24-h gastric pH c lose to neutral.Aim: To evaluate the effect of intravenous famotidine at a conventional dose of 40 mg/day on 24-h intragastric pH in patient s with a bleeding duodenal ulcer, and to determine the dose required t o maintain gastric pH > 6 by use of a Gastrojet (MIC, Switzerland) dev ice (a pH meter-controlled programmable pump). Methods: Twelve patient s (nine men, three women), aged 24-78 years, admitted for a bleeding d uodenal ulcer, were studied after active bleeding had stopped for at l east 6 h. Gastric pH was recorded for two consecutive 24-h periods, ea ch starting at 16.00 hours. The patients were fasted during these peri ods and received an infusion of 2.5 L of isotonic glucose. They were g iven famotidine, as a continuous i.v. infusion of 40 mg during one per iod, and at a rate determined by the Gastrojet during the other period (in a random sequence), with the aim of maintaining the gastric pH ab ove 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 b oth significantly higher during the Gastrojet period than during the c ontinuous 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 famotidin e delivered by the Gastrojet was 172 mg (range: 101-200 mg). The entir e 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 s ignificantly higher at night (22.00 to 07.00 hours) than during the re st 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 nigh t (6.3+/-0.8 mg/h vs. 8.4+/-0.5 mg/h; P < 0.02). Conclusion: We conclu de 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 pos sible to achieve this goal by using a much larger dose, preferably del ivered during the day.