Related Experiment Video
Updated: Oct 28, 2026

Instrumentation of Near-term Fetal Sheep for Multivariate Chronic Non-anesthetized Recordings
Published on: October 25, 2015
Pharmacokinetics of sulfonamides and trimethoprim in the donkey (Equus asinus)
1Department of Physiology and Therapeutics, Hassan II Agronomic and Veterinary Institute, Rabat, Morocco.
Abstract:
The body disposition of sulfadimidine (SDM), sulfadiazine (SDZ), sulfamethoxypyridazine (SMPZ) and a trimethoprim-sulfadimethoxine combination (TMP-SDMX) was investigated in the donkey. The four sulfonamides and TMP were injected intravenously at doses of 20 mg/kg (SDM, SDZ, SMPZ), 12.5 mg/kg (SDMX) and 2.5 mg/kg (TMP). The body clearance (ClB) of SDZ (1.70 +/- 0.14 ml/min/kg) was significantly higher than those of SDM (1.13 +/- 0.18 ml/min/kg), SMPZ (1.10 +/- 0.09 ml/min/kg) and SDMX (0.75 +/- 0.04 ml/min/kg). In contrast, the volume of distribution at steady state (Vss) was similar for the four sulfonamides (0.68 +/- 0.08 L/kg, 0.63 +/- 0.07 L/kg, 0.47 +/- 0.06 L/kg, and 0.46 +/- 0.05 L/kg for SDM, SDZ, SMPZ and SDMX, respectively). Both ClB and Vss were significantly higher for TMP (4.36 +/- 0.60 ml/min/kg and 2.71 +/- 0.86 L/kg) than for sulfonamides. Antipyrine ClB (3.49 +/- 0.35 ml/min/kg) and Vss (0.66 +/- 0.16 L/kg), determined in order to assess hepatic oxidative function and total body water volume, respectively, were either different from (ClB), or similar to (Vss), values calculated for sulfonamides. The results obtained were compared to those reported in horses.
Related Concept Videos
Pharmacokinetics in Pediatric Patients: Drug Excretion
Nonlinear Pharmacokinetics: Overview
Nonlinearity can arise due to the saturation of plasma protein-binding or...
Drug Metabolism: Phase II Reactions
Pharmacokinetics in Pediatric Patients: Drug Metabolism
Pharmacokinetics in Pediatric Patients: Overview and Drug Absorption
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase

