Dose-related effects of N-demethyl-N-isopropyl-8, 9-anhydroerythromycin A 6,9-hemiacetal on gastric emptying of solids in healthy human volunteers.

The purpose of our study was to evaluate the effects of a new nonantibiotic motilide derived from erythromycin, EM574, on gastric emptying and to evaluate its safety. Thirty healthy volunteers received one of five oral doses of EM574 (5, 10, 20, 30 mg and placebo) in a randomized, double-blind, five-period, cross-over design; each dosing period was separated by 1-wk washout. Gastric emptying was measured by 13C-octanoic acid breath test. A total of 10, 20, 30 mg of EM574 significantly accelerated both lag phase and gastric half-emptying time (P < .001) compared to placebo. The 5-mg dose of EM574 also significantly shortened the gastric half-emptying time (P < .05). Mean gastric half-emptying times were 173, 158, 147, 149 min with EM574 5, 10, 20, 30 mg, respectively (placebo, mean 189 min). EM574 accelerated gastric emptying in a dose-related manner (P < .001 for linear trend, P < .05 for quadratic trend). However, the 30-mg dose did not accelerate gastric emptying more than the 20-mg dose. EM574 was well tolerated; 7 of 56 participants receiving the 20- or 30-mg dose developed nausea, and only 2 of 28 receiving the 30-mg dose experienced vomiting. EM574 accelerates gastric emptying in a dose-dependent manner with minimal side effects after a single administration of up to 20 mg. EM574 shows promise for treatment of patients with impaired gastric emptying.