Influence of Co-Administration of Parbendazole on The Disposition Kinetics and Efficacy of Albendazole in Goats

A study was undertaken to understand the pharmacokinetics and efficacy of albendazole (ABZ) in goats with and without co-administration of ABZ with parbendazole (PBZ) at 7.5 and 4.5 mg/kg body weight, respectively. Plasma albendazole sulphoxide metabolite (active moiety), reached its maximum concentration of 0.322 and 0.325 μg/ml at 18 h of oral administration of ABZ alone and co-administration of ABZ with PBZ. No significant difference (P>0.05) in the values of other pharmacokinetic parameters could be observed except for elimination half-life, where significantly (P<0.05) increased values were observed in ABZ + PBZ treated goats. The nematodes were found resistant against ABZ alone (ED 50 on egg hatch assay was 0.196 μg thiabendazole/ml) while susceptible against the drug combination. The dominant nematode exhibiting resistance was Haemonchus spp. Almost unaltered or slightly reduced drug-parasite contact was observed in goats receivingABZ and PBZ combination.