Effect of erythromycin derivative EM523L on human interdigestive gastrointestinal tract

We investigated the effect of an erythromycin derivative, EM523L, on interdigestive gastrointestinal motor activity and plasma motilin concentrations in three healthy volunteers using an infused catheter system. We administered doses of 500, 1000, and 2000 micrograms of EM523L to each subject as well as physiological saline. EM523L induced interdigestive migrating contractions (IMCs) that originated in the stomach and migrated to the duodenum. This response was noted in all three subjects after each dose of EM523L, while no IMCs were induced by saline. There were no significant differences in the characteristics of the EM523L-induced IMC and the spontaneous IMC. The initiation time, ie, the interval between the start of EM523L infusion and the onset of the IMC became shorter in a dose-dependent manner. Plasma motilin concentrations increased significantly after EM523L administration, suggesting that motilin is involved in the mechanism of IMC induction by this drug.