title: The effect of phenylbutazone on the plasma disposition of penicillin G in the horse.
abstract: A pilot study in two ponies showed that the plasma concentrations of intramuscularly administered procaine penicillin were higher if phenylbutazone was administered concurrently. In two other trials, each involving five horses, intravenous sodium penicillin was administered with and without concurrent intravenously injected phenylbutazone, and procaine penicillin was injected intramuscularly with and without oral phenylbutazone. In both cases the plasma concentrations of penicillin were higher when phenylbutazone was given. The pharmacokinetic parameters indicated that the effect was probably due to a lower peripheral distribution because the penetration of penicillin into the tissues was greatly reduced.
authors.affiliation: Department of General and Large Animal Surgery, Faculty of Veterinary Medicine, State University, Utrecht, The Netherlands.
authors.forename: E C
authors.initials: EC
authors.lastname: Firth
authors.forename: J F
authors.initials: JF
authors.lastname: Nouws
authors.forename: W R
authors.initials: WR
authors.lastname: Klein
authors.forename: F
authors.initials: F
authors.lastname: Driessens
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001798:Blood Proteins / Q000378:metabolism; D004058:Diffusion; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005260:Female; D006736:Horses / Q000378:metabolism*; D007273:Injections, Intramuscular / Q000662:veterinary; D007275:Injections, Intravenous / Q000662:veterinary; D010400:Penicillin G / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D010653:Phenylbutazone / Q000008:administration & dosage / Q000494:pharmacology*; D011485:Protein Binding
chemical_list: D001798:Blood Proteins; D010653:Phenylbutazone; D010400:Penicillin G