Optimal dose of oral omeprazole for maximal 24 hour decrease of intragastric acidity.

In a series of 59 experiments in nine duodenal ulcer patients, 24 hour intragastric acidity was measured before, during, and after treatment with daily oral omeprazole. Omeprazole 10, 20, and 30 mg/day for one week caused a 37, 90, and 97% decrease of 24 hour intragastric acidity, respectively. No further decrease of acidity was observed when the dose of omeprazole was doubled to 60 mg/day, or after a second week of treatment with 30 mg/day. One week after stopping treatment with omeprazole (14 doses) there was a significant 26% decrease of 24 hour intragastric acidity, with full recovery seven weeks later. Fasting plasma gastrin concentration was significantly raised during treatment with all doses of omeprazole. Omeprazole 30 mg/day is the optimal dose for a maximal decrease of 24 hour intragastric acidity in duodenal ulcer patients.