Prinied in U. S. A. METABOLISM OF ALBENDAZOLE IN CATTLE, SHEEP, RATS, AND MICE

Nine metabolites of albendazole were identified in the urine of cattle, sheep, rats, and mice which had been given the labeled drug orally. Metabolic conversions included oxidation at sulfur, alkyl and aromatic hydroxylation, methylation at both nitrogen and sulfur, and carbamate hydrolysis. Unchanged albendazole was present in urine in only minor amounts. Albendazole (ABZ), methyl [5-(propyltbio)- 1H-benzimidazol-2-yl]carbamate, is the first broad-spectrum antheLmintic to have useful efficacy at low dose levels against all major economically important helniinth parasites infecting domestic animals (1). ABZ is widely used in sheep and cattle for control of gastrointestinal nematodes and tapeworms, lungworms, and liver flukes (2). It is also effective against metacestodes of Taenia saginaw in calves (3) and more exotic but difficult infections of Paragonimus kellicotti in cats (4) and Filaroides hirthi in dogs (5)