Pharmacokinetics of diminazene in combination with procaine and antipyrine in Trypanosoma evansi infected buffalo calves

Abstract

In the present investigation pharmacokinetic pattern of diminazene in combination with procaine and antipyrine in Trypanosolna evansi infected (group1) and T.evansi infected dexamethasone immunomodulated (group 2) buffalo calves, was assessed. The experimental infection of T. evansi was established with l07trypanosomes/calf by subcutaneous route. Apparently healthy male buffalo calves (3 for each group) between 9 months and 1 year of age, weighing 57-88 kg, were treated with a single ilm administration of a preparation containing diminazene, antipyrine and procaine in the ratio of 3.5: 4.16: 0.2 @ 7.86 mg.kg-1. The peak plasma levels were obtained at 15 min in both the groups, which were 10-12 fold higher than minimum therapeutic plasma levels of diminazene and the MEC was maintained up to 6 days in both the groups. The elimination half life of diminazene in group 1 and 2 was 156.92±150.46 and 142.62±116.55 h, respectively. There was considerable penetration of diminazene through biological membrane as was indicated by high value of apparent volume of distribution 2.l8±1.74 L.kg-1 and 2.03±.O.48 L.kg-1in groups 1 and 2, respectively. The extent of penetration into the erythrocytes was in the range of 11.67-63.53% of blood concentration in T.evansi infected buffalo calves and 14.68-47.25% of blood concentration in T.evansi infected and dexamethasone immunomodulated buffalo calves. Approximately 41 and 48% of total administered drug was excreted in urine within 24 h in groups 1 and 2, respectively. On the basis of kinetic data the priming and maintenance doses of diminazene in T.evansi infected (group 1) buffalo calves were calculated to be 3.86 and 2.74 mg.kg-1 and in T.evansi infected and dexamethasone immunomodulated (group 2) were 3.23 and 2.21 mg.kg-1, respectively, when diminazene is given along with procaine and antipyrine.