Pharmacokinetics, bioavailability and dosage regimen of sulphadimidine in camels (Camelus dromedarius) under hot, arid environmental conditions

A two-way crossover study was conducted in young Bikaneri camels (aged betw een 12 and 18 months) during the hot summer season to determine the bioavai lability, pharmacokinetics and dosage regimens of sulphadimidine (SDM). A d ose of 100 mg.kg(-1) of SDM was used to study both the intravenous and oral pharmacokinetics of the drug. Analysis of the intravenous data according t o a two-compartment pharmacokinetic model revealed that SDM was well distri buted in the body (Vd((area)): 0.862 L.kg(-1)), had an overall body clearan ce of 0.035 +/- 0.019 L.h(-1).kg(-1) and the elimination of half-lives was in the range of 14.2 to 20.6 h. The mean maximum plasma SDM concentration f ollowing oral administration was 63.23 +/- 2.33 mu g.mL(-1), which was achi eved 24 h after the oral administration. The mean bioavailability of SDM fo llowing oral administration was approximately 100 %. TO achieve and maintai n the therapeutically satisfactory plasma sulphadimidine levels of greater than or equal to 50 mu g.mL(-1), the optimum dosage regimen for camels foll owing either intravenous or oral administration would be 110 mg.kg(-1) as t he priming dose and 69 mg.kg(-1) as the maintenance dose, to be repeated at 24 h intervals. (C) Inra/Elsevier, Paris.