Particular aspects of the pharmacokinetics of erythromycin

Abstract

The absorption of erythromycin stearate and erythromycin ethyl succinate was studied both in six normal healthy subjects to assess the effects of body position, and 23 inpatients with small bowel disorders (12 patients coeliac disease, 11 patients Crohn's disease) to compare absorption in such cases with the normal absorption pattern. Erythromycin stearate showed no significant difference in the mean plasma concentrations or 0–8 hour urinary excretion between walking and supine subjects at any sampling time. The peak was delayed from one hour (walking) to two hours (supine). Erythromycin ethyl succinate gave similar results in walking and supine subjects. The mean plasma concentration was higher throughout the eight hours in the supine subjects and significantly so after three hours. In patients with coeliac and Crohn's disease the absorption of erythromycin ethyl succinate was similar, with a shift to the left in the plasma concentration/time curve, which suggests earlier absorption. After administration of the stearate there was a reduction in the mean ± SEM plasma erythromycin at most sampling times in patients with Crohn's disease.