Effect of Intravenous Infusion of Omeprazole and Ranitidine on Twenty-Four-Hour Intragastric pH in Patients with a History of Duodenal Ulcer

Abstract

The effect on intragastric pH of two different dose regimens of continuous intravenous infusion of omeprazole (4 or 8 mg/h after a bolus of 80 mg), and ranitidine (0.25 mg/kg/h after a bolus of 50 mg) was studied in 10 patients with duodenal ulcer disease in symptomatic remission. The pH was monitored over 24-hour periods during fasting in a cross-over, randomised design including a baseline period. With the high omeprazole dose it was possible to maintain a pH ≥ 4 in all patients but 1 and 6 of the patients also maintained a pH ≥6. The lower dose of omeprazole seemed to be somewhat less effective. Continuous infusion of ranitidine was as efficient as the higher omeprazole infusion although with a tendency to decreased pH levels towards the end of the 24-hour period. Thus, in order to obtain consistently high pH levels of 4-6 over a prolonged period a continuous infusion of omeprazole, an 80-mg bolus plus a continuous infusion of 8 mg/h seem to be needed.

Critical Review of Acid Suppression in Nonvariceal, Acute, Upper Gastrointestinal Bleeding

“…PPIs have short half-lives in the circulation. Since PPIs bind only to actively secreting 85-90% [74][75][76].…”

“…It is unclear whether more rapid initi-8 mg/h of OME or PAN has been shown to be highly effective in rapidly and consistently maintaining pH 6.0 ation of therapy, both endoscopic and medical, would offer additional benefits. An effective regimen appears to in the stomach [47,[74][75][76][77]. In a study of IV PAN, Brunner et al [74] found that this dose was able to maintain pH be a loading dose of 80 mg administered by bolus injection followed by 8 mg/h by CI for at least 3 days.…”

“…Several studies with control within 1 h of administration, particularly with the 80-mg dose. It has a short mean plasma terminal OME have shown similar high rates of acid suppression [75,76]. Although the study by Labenz et al [76] reported elimination half-life of 0.9-1.9 h. Both the area under the curve and maximum serum concentration show dose no difference overall between a high and lower infusion rate, they did report that 4 patients, in whom pH was linearity over the dose range from 5 to 80 mg [69,70].…”

Use of omeprazole in life-threatening metabolic alkalosis

“…With this regimen, we initially had a successful response, but the effect seemed to diminish with time. Some studies have demonstrated the need for higher doses of up to 80 mg as a bolus followed by an infusion of 8 mg/h to achieve consistently a gastric pH of 4 to 6 over a prolonged period [5]. This dose may well have been more effective for the extended period during which our patient was treated.…”

Intravenous Pantoprazole: A New Tool for Acutely Ill Patients Who Require Acid Suppression

“…This well designed trial comprising 1005 patients reported no significant differences in rebleeding rates, surgical requirements and mortality between famotidine and placebo (85). Potential explanations for the H 2 RA's lack of efficacy in this setting include their minimal effects on acid stimulated by gastrin or acetylcholine (86), and the development of tolerance to their acid suppressive effects, even during short term use (87)(88)(89)(90)(91). Because PPIs are more potent inhibitors of acid suppression and have not been associated with tolerance, they may be expected to provide an incremental benefit over the H 2 RAs.…”