Continuous intravenous infusions of famotidine maintain high intragastric pH in duodenal ulcer.

Abstract

SUMMARY Three double blind crossover studies were carried out to assess the ability of primed infusions of famotidine to raise intragastric pH over 24 hours in 12 duodenal ulcer patients. pH was measured continuously using intragastric electrodes and solid state recording devices. The studies compared the effects of placebo, famotidine 10 mg bolus injection iv followed by continuous infusions of 3.2 mg/h and 4 mg/h in random order. Gastric acidity decreased significantly with both dose regimens (p<00005) but the effects of either dosage were similar. During fasting median pH rose from 1.35 to 7.1 and 7.05 respectively. During the day, when standard meals were taken, median pH rose from 1.30 to 4-3 and 3.65 respectively. Despite continuous infusions the H2-antagonist was less effective during this time. The latter finding raises questions about gastric secretory control during the day when food is eaten.Intravenous antisecretory drugs are commonly used in patients with gastrointestinal bleeding,'2 in intensive care units34 and in anaesthesia.'6 The aim of such therapy is to raise the pH of the gastric milieu to a level at which peptic activity is minimal so that clot or mucosal digestion is limited. While it has been suggested that rebleeding from peptic lesions is decreased when pH rises to about pH 4,7 clear evidence that H2-receptor antagonists reduce rebleeding rates or mortality is lacking. A positive trend suggesting efficacy of cimetidine and ranitidine exists' and a possible reason for such limited success is that existing dosage regimens produce less than optimum changes in gastric pH.' It is clear that greater pharmacodynamic responses follow continuous infusions of H2-antagonists compared with bolus injections. 1"14 We have therefore measured the effect of continuous infusions of the new H2-receptor antagonist, famotidine (MSD, Yamanouchi), on gastric acidity measured continuously by intragastric glass electrodes.

Role of Intravenous Omeprazole in Patients with High-Risk Peptic Ulcer Bleeding After Successful Endoscopic Epinephrine Injection: A Prospective Randomized Comparative Trial

“…In previous studies, patients received H-2 receptor-antagonists (H2RAs) intravenously after successful endoscopic hemostasis. In this way, intragastric pH could not be maintained higher than 4.0 for a long period in such patients (9)(10)(11)(12). Therefore, their rebleeding rates were higher than expected.…”

Effect of intragastric pH on control of peptic ulcer bleeding

“…At conventional recommended doses of H 2 RA, intragastric pH could not be maintained at higher than 4.0 for a long period. 9,10,19 In our present pilot study, we found that cimetidine (1600 mg/day) could increase intragastric pH > 6 for a period of time in patients with duodenal ulcer, while the lower doses could not. When 1600 mg/day cimetidine was used, we achieved a mean intragastric pH of 5.4 ± 1.6.…”

Single Morning and Nightly Doses of Ranitidine 300 mg: An Appraisal of Their Antisecretory Effects by Continuous pH Monitoring

“…However, the underlying mechanisms by which the action of H2 receptor blockers is partially bypassed remain speculative [23]. The most plausible hypothesis sustains that other pathways, i.e.…”