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Disposition and tolerance of suxibuzone in horses
Author(s) -
JARAIZ M. V.,
RODRIGUEZ C.,
ANDRES M. D. SAN,
GONZALEZ F.,
ANDRES M. I. SAN
Publication year - 1999
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/j.2042-3306.1999.tb03841.x
Subject(s) - oxyphenbutazone , phenylbutazone , chemistry , horse , synovial fluid , pharmacokinetics , plasma concentration , pharmacology , chromatography , medicine , pathology , biology , paleontology , alternative medicine , osteoarthritis
Summary Suxibuzone (SBZ), a nonsteroidal anti‐inflammatory drug, was administered to 6 horses at a dose rate of 7.5 mg/kg bwt by intravenous (i.v.) route. Plasma and synovial fluid concentrations of suxibuzone and its main active metabolites, phenylbutazone (PBZ) and oxyphenbutazone (OPBZ), were measured simultaneously by a sensitive and specific high‐performance liquid chromatographic method. The pharmacokinetic parameters were determined by noncompartmental analysis. Plasma SBZ concentrations rapidly decreased and were not detectable beyond 20 min after treatment. The parent drug was not detected in any synovial fluid samples. Average maximum plasma concentrations of PBZ (16.43 μg/ml) and OPBZ (2.37 μg/ml) were attained at 0.76 and 7.17 h, respectively. The mean residence time (MRT) of PBZ was 6.96 h in plasma. Oxyphenbutazone plasma concentrations were below those reached by phenylbutazone during the first 12 h after suxibuzone administration, even though its values were detectable for at least 24 h (MRT = 10.65 h). Plasma concentrations of PBZ and OPBZ exceeding EC 50 and IC 50 of TXB 2 and PGE 2 were reached by at least 12 h. Synovial fluid concentrations of PBZ and OPBZ were 2.87 ± 0.37 μg/ml and 0.97 ± 0.08 ug/ml at 9 h after suxibuzone administration and exceeded IC 50 of PGE 2 for at least this time. In the present study, suxibuzone was well tolerated following i.v. injection.