Pharmacokinetics of phenylbutazone and its metabolite oxyphenbutazone in miniature donkeys.
Abstract: To describe the pharmacokinetics of phenylbutazone and oxyphenbutazone after IV administration in miniature donkeys. Methods: 6 clinically normal miniature donkeys. Methods: Blood samples were collected before and 5, 10, 20, 30, 45, 60, 90, 120, 180, 240, 300, 360, and 480 minutes after IV administration of phenylbutazone (4.4 mg/kg of body weight). Serum was analyzed in triplicate by use of high-performance liquid chromatography for determination of phenylbutazone and oxyphenbutazone concentrations. The serum concentration-time curve for each donkey was analyzed separately to estimate model-independent pharmacokinetic variables. Results: Serum concentrations decreased rapidly after IV administration of phenylbutazone, and they reached undetectable concentrations within 4 hours. Values for mean residence time ranged from 0.5 to 3.0 hours (median, 1.1 hour), whereas total body clearance ranged from 4.2 to 7.5 ml/kg/min (mean, 5.8 ml/kg/min). Oxyphenbutazone appeared rapidly in the serum; time to peak concentration ranged from 13 to 41 minutes (mean, 26.4 minutes), and peak concentration in serum ranged from 2.8 to 4.0 mg/ml (mean, 3.5 microg/ml). Conclusions: Clearance of phenylbutazone in miniature donkeys after injection of a single dose (4.4 mg/kg, IV) is rapid. Compared with horses, miniature donkeys may require more frequent administration of phenylbutazone to achieve therapeutic efficacy.
Publication Date: 2001-05-09 PubMed ID: 11341383DOI: 10.2460/ajvr.2001.62.673Google Scholar: Lookup
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- Journal Article
Summary
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The research article examines how the bodies of miniature donkeys process (metabolize) the drug phenylbutazone and its byproduct, oxyphenbutazone after it has been administered intravenously. It suggests that compared to horses, miniature donkeys might need more frequent doses of this drug to achieve its beneficial effects.
Research Methodology
- The study was conducted on six healthy miniature donkeys.
- Each donkey was given a single intravenous dose of phenylbutazone, which is a nonsteroidal anti-inflammatory drug often used in veterinary medicine. The dose was set to 4.4 mg/kg of the donkey’s body weight.
- Blood samples were taken at intervals before and after the injection, up to 480 minutes (8 hours) post-injection to track how the drug was processed over time.
- These samples were analyzed using high-performance liquid chromatography, which is a technique used to separate, identify and quantify each component in a mixture. This enabled the researchers to determine concentrations of phenylbutazone and its metabolite, oxyphenbutazone in the blood.
Research Findings
- The researchers found that serum concentrations of phenylbutazone decreased rapidly after it was administered, reaching undetectable levels within four hours. The mean residence time (meaning the time the drug stayed in the body) ranged from 0.5 to 3.0 hours, with a median time of 1.1 hrs.
- The drug’s total body clearance (the time it took to remove the drug from the body) ranged between 4.2 to 7.5 ml/kg/min, with an average clearance at 5.8 ml/kg/min.
- Oxyphenbutazone appeared rapidly in the serum; the average time to peak concentration was 26.4 minutes, and the peak concentration in the serum ranged from 2.8 to 4.0 mg/ml.
Conclusions
- The research concluded that the clearance – or processing and removal – of phenylbutazone in miniature donkeys occurs swiftly after a single intravenous dose of the drug.
- Due to this rapid clearance of the drug compared to larger animals such as horses, miniature donkeys may require more frequent administration of phenylbutazone to achieve the same therapeutic effects.
Cite This Article
APA
Matthews NS, Peck KE, Taylor TS, Mealey KL.
(2001).
Pharmacokinetics of phenylbutazone and its metabolite oxyphenbutazone in miniature donkeys.
Am J Vet Res, 62(5), 673-675.
https://doi.org/10.2460/ajvr.2001.62.673 Publication
Researcher Affiliations
- Texas Veterinary Medical Center, Texas A&M University, College Station 77843, USA.
MeSH Terms
- Animals
- Anti-Inflammatory Agents, Non-Steroidal / blood
- Anti-Inflammatory Agents, Non-Steroidal / pharmacokinetics
- Area Under Curve
- Equidae / metabolism
- Equidae / physiology
- Male
- Oxyphenbutazone / blood
- Oxyphenbutazone / pharmacokinetics
- Phenylbutazone / blood
- Phenylbutazone / pharmacokinetics
Citations
This article has been cited 2 times.- Saleem S, Khan R, Afzal M, Kazmi I. Oxyphenbutazone promotes cytotoxicity in rats and Hep3B cellsvia suppression of PGE(2) and deactivation of Wnt/β-catenin signaling pathway. Mol Cell Biochem 2018 Jul;444(1-2):187-196.
- Regan Nee Ashley FH, Hockenhull J, Pritchard JC, Waterman-Pearson AE, Whay HR. Clinical abnormalities in working donkeys and their associations with behaviour. Vet Rec Open 2015;2(1):e000105.
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