Pharmacokinetics, bioavailability and dosage regimen of sulphadiazine (SDZ) in camels (Camelus dromedarius).

The pharmacokinetics of sulphadiazine (SDZ) (100 mg/kg, body weight) were investigated in six camels (Camelus dromedarius) after intravenous (i.v.) and oral (p.o.) administration. Following i.v. administration, the overall elimination rate constant (beta) was 0.029 +/- 0.001/h and the half-life (t1/2beta) was 23.14 +/- 1.06 h. The apparent volume of distribution (Vd(area)) was 0.790 +/- 0.075 L/kg and the total body clearance (ClB) was 23.29 +/- 2.50 mL/h/kg. After p.o. administration, SDZ reached a peak plasma concentration (Cmax(cal.)) of 62.93 +/- 2.79 microg/mL at a post injection time of (Tmax(cal.)) 22.98 +/- 0.83 h. The elimination half-life was 19.79 +/- 1.22 h, not significantly different from that obtained by the i.v. route. The mean absorption rate constant (Ka) was 0.056 +/- 0.002 h(-1) and the mean absorption half-life (t1/2Ka) was 12.33 +/- 0.37 h. The mean availability (F) of sulphadiazine was 88.2 +/- 6.2%. To achieve and maintain therapeutically satisfactory plasma SDZ levels of > or = 50 microg/mL, the priming and maintenance doses would be 80 mg/kg and 40 mg/kg intravenously and 90 mg/kg and 45 mg/kg orally, respectively, to be repeated at 24 h intervals.