Premium
Pharmacokinetics of azithromycin after intravenous and intramuscular administration to goats
Author(s) -
CÁRCELES C. M.,
FONT A.,
ESPUNY A.,
FERNÁNDEZVARÓN E.,
SERRANO J. M.,
ESCUDERO E.
Publication year - 2005
Publication title -
journal of veterinary pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.527
H-Index - 60
eISSN - 1365-2885
pISSN - 0140-7783
DOI - 10.1111/j.1365-2885.2004.00626.x
Subject(s) - azithromycin , pharmacokinetics , bioavailability , volume of distribution , pharmacology , cmax , tolerability , bioequivalence , intramuscular injection , oral administration , absorption (acoustics) , medicine , chemistry , antibiotics , adverse effect , biochemistry , physics , acoustics
Azithromycin is the first of a class of antimicrobial agents designated azalides. The aim of the present study was to investigate the disposition pharmacokinetics of azithromycin in goats and determine its bioavailability. A cross‐over study was carried out in two phases separated by 30 days. Azithromycin was administered at a single dose of 20 mg/kg body weight by i.v. and i.m. routes. Plasma concentrations of azithromycin were determined by a modified agar diffusion bioassay. After a single i.v. dose plasma concentrations were best fitted to a three‐compartment open model. A two‐compartment open model with first‐order absorption fitted best after i.m. administration. The values of the pharmacokinetic parameters after i.v. administration were: half‐life 32.5 h, apparent volume of distribution at the steady‐state 34.5 L/kg, clearance 0.85 L/kg. and mean residence time (MRT) 40.1 h. After i.m. administration half‐life of 45.2 h, a MRT of 60.3 h, maximum plasma concentration 0.64 mg/L and a bioavalability 92.2% were obtained. The pharmacokinetic parameters of azithromycin after i.m. administration, principally its long half‐life and high bioavailability, could provide an alternative to the oral route of administration in goats, although more studies are needed to establish a suitable pharmaceutical formulation, propose optimun dosage regimens, investigate clinical efficacy and study the tolerability of repeated doses.