The effect of ranitidine on the gastroduodenal motility as determined by the maximal pressure periods.

Twenty healthy subjects with a mean age of 23.5 years were studied. Identically appearing tablets of 150 mg ranitidine or placebo were given to each subject twice daily for 2 days. After an overnight fast the same dosage of tablets was given 2 h before introduction of two fiberoptic transducers, the tips of which were localized to the mid-portion of the gastric antrum and the upper third of the duodenum. The double-blind crossover study showed in the placebo period a mean duration of the maximal pressure periods (MPP) of 5.5 min in the duodenum and 3.5 min in the antrum of the stomach. The cyclic length (CL) and the cyclic displacement (CD) in the duodenum were 58 min and 67 mm/min, respectively. After ranitidine the duration of the MPP was significantly longer. The CL was also longer in the duodenum, whereas the CD was shortened, indicating a reduction of the wave movements from the stomach antrum to the duodenum in the ranitidine periods.