Effects of prior feeding on pharmacokinetics and estimated bioavailability after oral administration of a single dose of microencapsulated erythromycin base in healthy foals

Jeffrey Lakritz, William D Wilson, Antoinette E. Marsh, Judy E. Mihalyi

Research output: Contribution to journalArticlepeer-review

26 Scopus citations

Abstract

Objective - To determine effects of prior feeding on pharmacokinetics and estimated bioavailability of orally administered microencapsulated erythromycin base (MEB) in healthy foals. Animals - 6 healthy foals, 3 to 5 months old. Procedure - Foals were given 2 doses of MEB (25 mg/kg of body weight, PO). One dose was administered after food was withheld overnight, and the other was administered after foals had consumed hay. The study used a crossover design with a 2-week period between doses. Blood was collected via a jugular vein prior to and at specific times after drug administration. Concentrations of erythromycin A and anhydroerythromycin A in plasma were determined, using high-performance liquid chromatography. Results pharmacokinetic analysis of plasma concentration-time data for food-withheld and fed conditions were compared. Results - Plasma concentrations of erythromycin A for foals were lower after feeding than concentrations when food was withheld. Area under the plasma concentration-time curve, maximum plasma concentration, and estimated bioavailability were greater in foals when food was withheld than when foals were fed. Anhydroerythromycin A was detected in plasma after administration of MEB in all foals. Conclusions and Clinical Relevance - Foals should be given MEB before they are fed hay. Administration of MEB to foals from which food was withheld overnight apparently provides plasma concentrations of erythromycin A that exceed the minimum inhibitory concentration of Rhodococcus equi for approximately 5 hours. The dosage of 25 mg/kg every 8 hours, PO, appears appropriate.

Original languageEnglish (US)
Pages (from-to)1011-1015
Number of pages5
JournalAmerican Journal of Veterinary Research
Volume61
Issue number9
StatePublished - Sep 2000

ASJC Scopus subject areas

  • veterinary(all)

Fingerprint Dive into the research topics of 'Effects of prior feeding on pharmacokinetics and estimated bioavailability after oral administration of a single dose of microencapsulated erythromycin base in healthy foals'. Together they form a unique fingerprint.

Cite this