Comparative pharmacokinetics of caffeine and three metabolites in clinically normal horses and donkeys.
Abstract: To determine whether clearance of capacity-limited drugs in horses differs from that in donkeys by comparing the serum disposition of caffeine and its metabolites, theophylline, theobromine, and paraxanthine after i.v. administration of caffeine to horses and donkeys. Methods: 4 healthy horses and 5 healthy donkeys. Methods: Blood samples were collected from each animal at time 0 (before) and 5, 10, 15, 20, 30, and 45 minutes, and 1, 2, 3, 4, 6, 8, 12, 24, 30, 36, 48, 54, 60, 72, and 96 hours after IV administration of a bolus of caffeine. Serum was analyzed in triplicate by high-performance liquid chromatography to determine caffeine, theophylline, theobromine, and paraxanthine concentrations. The serum concentration-time curves for each animal were analyzed separately to estimate model-independent pharmacokinetic variables. Results: Mean pharmacokinetic values for caffeine, theophylline, and paraxanthine did not differ significantly in horses, compared with donkeys. Mean peak serum concentration of theobromine was significantly higher in donkeys, compared with horses. Conclusions: Clearance of the capacity-limited drug caffeine does not appear to differ in horses, compared with donkeys. Conclusions: For some drugs that undergo hepatic metabolism, the dose and dose interval used for horses may be appropriate for use in donkeys.
Publication Date: 1997-08-01 PubMed ID: 9256975
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- Comparative Study
- Journal Article
Summary
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The research article explores how capacity-limited drugs like caffeine, and its metabolites theophylline, theobromine, and paraxanthine are processed differently in horses and donkeys. This study compares serum disposition after intravenous administration of caffeine to both horses and donkeys, revealing no significant difference for most substances but a higher concentration of theobromine in donkeys.
Objective and Methodology
- The researchers aimed to understand if the clearance of capacity-limited drugs (drugs that are cleared at a maximum rate regardless of their concentration) in horses differed from that in donkeys.
- The particular drug used for this study was caffeine. Its metabolites, theophylline, theobromine, and paraxanthine, were also studied.
- For this purpose, a group of 4 healthy horses and 5 healthy donkeys were administered caffeine intravenously.
- The serum was extracted from each animal at regular intervals – from 0 (prior to caffeine administration) up to 96 hours after caffeine administration.
- The serum was then analyzed for the presence and concentration of caffeine and its metabolites.
Results and Conclusions
- The serum concentration-time curves for each animal were analyzed to estimate pharmacokinetic variables, a branch of pharmacology dedicated to the fate of substances administered to a living organism.
- It was found that the mean pharmacokinetic values for caffeine, theophylline, and paraxanthine did not significantly differ between horses and donkeys.
- However, the peak serum concentration of theobromine was significantly higher in donkeys compared to horses, indicating a possible difference in how theobromine is metabolized by the two species.
- Overall, the researchers concluded that the clearance of capacity-limited drug caffeine does not appear to differ significantly between horses and donkeys. This might mean some drugs undergoing hepatic metabolism might have similar dosing guidelines for both horses and donkeys.
Cite This Article
APA
Peck K, Mealey KL, Matthews NS, Taylor TS.
(1997).
Comparative pharmacokinetics of caffeine and three metabolites in clinically normal horses and donkeys.
Am J Vet Res, 58(8), 881-884.
Publication
Researcher Affiliations
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, Texas A&M University, College Station 77840, USA.
MeSH Terms
- Animals
- Caffeine / blood
- Caffeine / pharmacokinetics
- Equidae
- Female
- Horses
- Male
- Metabolic Clearance Rate
- Species Specificity
- Theobromine / blood
- Theobromine / pharmacokinetics
- Theophylline / blood
- Theophylline / pharmacokinetics
- Time Factors
Citations
This article has been cited 3 times.- Brent RL, Christian MS, Diener RM. Evaluation of the reproductive and developmental risks of caffeine. Birth Defects Res B Dev Reprod Toxicol 2011 Apr;92(2):152-87.
- Yang B, Liu S, Cheng J, Qu H, Guo Y, Ji C, Wang Y, Zhao S, Huang S, Zhao L, Ma Q. Pharmacokinetics of Enrofloxacin in Plasma, Urine, and Feces of Donkey (Equus asinus) after a Single Intragastric Administration. Antibiotics (Basel) 2024 Apr 12;13(4).
- Buono F, Veneziano V, Veronesi F, Molento MB. Horse and donkey parasitology: differences and analogies for a correct diagnostic and management of major helminth infections. Parasitology 2023 Oct;150(12):1119-1138.
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