Clinical pharmacokinetics in veterinary medicine

Area of Science:

• Comparative pharmacology and pharmacokinetics
• Drug disposition and metabolism across species

Background:

• Veterinary and human pharmacology diverge due to varied species in drug use and study.
• Dose-effect relationships in animals, like humans, depend on pharmacokinetic and pharmacodynamic integration.
• Therapeutic plasma concentrations are generally consistent across species, but dosage may vary.

Purpose of the Study:

• To explore species-specific variations in drug pharmacokinetics and pharmacodynamics.
• To explain differences in drug bioavailability, absorption, disposition, and elimination.
• To highlight the application of pharmacokinetics in predicting drug withdrawal times and understanding residue profiles.

Main Methods:

• Comparative pharmacokinetic studies analyzing drug absorption, distribution, metabolism, and excretion (ADME) across species.
• Investigation of bioavailability differences, particularly with oral versus parenteral administration.
• Utilization of marker substances to quantify metabolic pathway activity and excretion efficiency.

Main Results:

• Significant species variations in oral drug bioavailability exist, especially between ruminants, horses, and carnivores.
• Parenteral administration can mitigate bioavailability differences; formulation and injection site impact it in horses and cattle.
• Elimination rates, rather than distribution or metabolism, are the primary drivers of pharmacokinetic species variation; herbivores metabolize drugs faster than carnivores.

Conclusions:

• Species-specific pharmacokinetic behavior necessitates adjustments in drug dosage and administration intervals.
• Pharmacokinetic principles are vital for optimizing drug therapy in veterinary medicine and ensuring food safety through residue prediction.
• Humans exhibit slower drug metabolism compared to domestic animals, impacting therapeutic strategies.