Inhibition of the histamine-stimulated gastric secretion in healthy subjects by the H2-receptor antagonist ranitidine.

The gastric secretion was examined for 30 min before and 120 min during intravenous infusion of 3 microgram/kg/h of histamine dihydrochloride. In eight subjects physiological saline solution was given as infusion in addition to histamine (controls), whereas nine subjects received ranitidine in doses increased every half hour--0.06, 0.12, 0.24, and 0.48 mg/kg/h. The infusion of ranitidine resulted in a significant reduction of volume of gastric juice both when compared with the unstimulated periods before histamine and with those of subjects receiving the saline solution. Similarly, the acid output was reduced still more significantly during infusion of ranitidine, the output being about zero in the last hour. The ranitidine dose used was about five time lower than that previously used of cimetidine. No side effects were observed.