Biliary excretion of erythromycin after parenteral administration

1 The biliary excretion of erythromycin has been studied following parenteral administration in 23 patients. 2 Mean bile levels of the drug were approximately ten times higher than corresponding serum concentrations 1 h after i.v. (erythromycin lactobionate) and i.m. (erythromycin ethylsuccinate) injection. 3 Thus, unlike many antimicrobial agents, these compounds are well concentrated in the bile.