Effect of midecamycin acetate on gastrointestinal motility in humans.

The effect was studied on gastrointestinal motor activity of three different macrolides (erythromycin, roxithromycin and midecamycin acetate), administered by mouth in therapeutic doses. This placebo-controlled study was performed in 12 normal human subjects by means of intraluminal pressure measurements in the gastric antrum, duodenum and upper jejunum. In each subject, three manometries were done for 5 h in the interdigestive period and for 3 h postprandially. In the interdigestive period, midecamycin acetate did not affect the characteristics of the gastric migrating motor complex (MMC) and did not increase the number of antral contractions or the gastric motility index as compared to the placebo. Erythromycin and roxithromycin increased the number of antral contractions (24.5 +/- 11 versus 15.2 +/- 7 and 28.4 +/- 12 versus 14.9 +/- 5.9 respectively) and the motility index (4.05 +/- 0.5 versus 3.17 +/- 0.6 and 4.38 +/- 0.2. versus 3.64 +/- 0.7 respectively) as compared to the placebo. In the postprandial period, the number of antral contractions was not significantly increased by any of the three antibiotics. The postprandial antral motility index was not significantly increased by midecamycin acetate. In contrast, the postprandial antral motility indexes after erythromycin (4.4 +/- 0.5) and after roxithromycin (4.3 +/- 0.2) were significantly greater than after the placebo. In the upper small intestine, erythromycin elicited an increased number of phase-III-like activity events and roxithromycin shortened the MMC cycle length. Midecamycin acetate had no effect on interdigestive upper jejunal motility. The postprandial jejunal motor activity was not altered by any of the three antibiotics neither during the interdigestive nor the postprandial periods.(ABSTRACT TRUNCATED AT 250 WORDS)