Erythromycin elicits opposite effects on antro-bulbar and duodenal motility: analysis in diabetics by cineradiography.

We have previously demonstrated by cineradiography analysis that erythromycin (Ery) increases antral contractility and antropyloric coordination in diabetics. The aim of this study was to further characterize antro-bulbar and duodenal motility after Ery i.v. administration. Fourteen diabetic patients (mean age 61.2 years) were randomly allocated to receive either 100 or 500 mg of Ery intravenously 4 hours after a standard solid liquid meal. After ingestion of a barium sulfate suspension, a series of 15 fluorographic plates (one every two seconds) was performed. the same procedure was repeated twice for each subject with a delay of 3 days once before and once after Ery. Antral, bulbar and duodenal areas and evolution diagrams were calculated in baseline conditions and after Ery administration using a graphic table connected to a microcomputer. No differences were found between the two doses of the drug. Ery significantly decreased antral (1284 +/- 268 mm2 vs 704 +/- 181 mm2; P < 0.01) and bulbar areas (127 +/- 26 mm2 vs 73 +/- 21 mm2; P < 0.01). In contrast, duodenal areas were significantly increased after Ery (875 +/- 112 mm2 vs 575 +/- 112 mm2; P < 0.01). This study suggests that the known prokinetic effect of Ery on gastric emptying seen in diabetic patients could be related to an increase of motility in the antrum and in the bulb simultaneously with a relaxation in the duodenum.