Abstract
The H2-blockers have become front line therapy for reflux oesophagitis. However, there are conflicting views regarding the change in the lower oesophageal sphincter pressure (LESP) by H2-blockers. The effects of three H2-blockers, cimetidine, ranitidine, and famotidine, on the LESP were studied in 56 normal subjects. Cimetidine, ranitidine and famotidine were administer-ed intravenously at a does of 200 mg, 50 mg, and 20 mg, respectively. The LESP was measured using an open-tip and pull-through method, infused catheter method, every 5-10 minutes, starting before treatment up to 60 minutes after administration. The LESP increased significantly in the famotidine and ranitidine groups at 5-40 minutes and 10-40 minutes after administration, respectively, However, no significant increase was observed in the cimetidine group. It seemed that the effects of H2-blockers on LESP have relation to strength of inhibition on gastric acid secretion. The effects of famotidine and ranitidine on thce LESP were also assessed in the same manner in four reflux oesophagitis patients. Both drugs seemed to increase the LESP.
