Twenty-four hour intragastric acidity during treatment with oral omeprazole.

In a series of 59 experiments on nine duodenal ulcer patients, 24-hour intragastric acidity was measured before, during and after treatment with daily oral omeprazole. Omeprazole, 10, 20, ro 30 mg/day for 1 week, caused a 37%, 90%, and 97% decrease respectively of 24-hour intragastric acidity. 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 still a significant 26% decrease of 24-hour intragastric acidity, with full recovery 7 weeks later. Fasting plasma gastrin concentration was significantly elevated during treatment with all doses of omeprazole. The optimal dose of omeprazole is 30 mg/day for a maximal decrease of 24-hour intragastric acidity in duodenal ulcer patients.