Effect of sequential erythromycin and octreotide on antroduodenal manometry

Background: In earlier studies, erythromycin stimulated but octreotide inhi bited gastric antral contractions, as each drug induced phase 3-like episod es. Methods: To assess the effect of erythromycin pretreatment on octreotide-in duced changes in antroduodenal motility, 16 patients were studied (mean age , 8.7 +/- 1.5 years, 8 male): 6 with severe gastroesophageal reflux, 4 with cyclic vomiting, 3 with gastroparesis, 2 with chronic intestinal pseudo-ob struction, and 1 with Crohn's disease and unexplained nausea and vomiting. After recording fasting antroduodenal motility for 3 hours, 1 mg/kg intrave nous erythromycin was administered over 30 minutes. Sixty minutes after the erythromycin infusion, 0.5 mu g/kg subcutaneous octreotide was administere d, followed 1 hour later by a meal. Results: Phase 3 occurred spontaneously in 10 patients and after erythromyc in in 12 patients. When administered after erythromycin, octreotide immedia tely induced phase 3s contractions in 15 patients, beginning in the antrum. In 7 children, some of the octreotide-induced phase 3s did not propagate. After the meal, antral contractions continued in all patients. The fed patt ern was replaced in 14 patients by alternating phase 3 and phase 1 activiti es. Conclusions: Pretreatment with erythromycin prevented octreotide-induced in hibition of antral contractions. Inhibition of antral contractions by octre otide may be mediated through either a direct or indirect suppression of mo tilin release, because antral contractions persist after pretreatment with the motilin receptor agonist erythromycin.