title: Pharmacokinetics and tissue tolerance of azithromycin after intramuscular administration to rabbits.
abstract: The pharmacokinetics of azithromycin after intravenous and intramuscular injection at a single dose rate of 10mg/kg bodyweight were investigated in rabbits by using a modified agar diffusion bioassay for determining plasma concentrations. The plasma creatine kinase activity was determined after i.m. administration for the evaluation of the tissue tolerance. The elimination half-lives of azithromycin after intravenous and intramuscular administration were 24.1 and 25.1h, respectively. After intramuscular administration mean peak plasma concentration was 0.26+/-0.01 mg/L and bioavailability was 97.7%. Plasma CK activity rose sharply within 8h after i.m. injection of azithromycin; activity returned to pre-treatment level by 48-72 h post-treatment. The transient rise in serum CK activity indicates some degree of muscle tissue damage at the injection site.
authors.affiliation: Departamento de Farmacología, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30071 Murcia, Spain. escudero@um.es
authors.forename: E
authors.initials: E
authors.lastname: Escudero
authors.forename: E
authors.initials: E
authors.lastname: Fernández-Varón
authors.forename: P
authors.initials: P
authors.lastname: Marín
authors.forename: A
authors.initials: A
authors.lastname: Espuny
authors.forename: M D
authors.initials: MD
authors.lastname: Nájera
authors.forename: C M
authors.initials: CM
authors.lastname: Cárceles
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D017963:Azithromycin / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D007273:Injections, Intramuscular; D007275:Injections, Intravenous; D008297:Male; D011817:Rabbits / Q000378:metabolism*; D011897:Random Allocation
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin