In vitro Metabolism of Bumetanide.

A new metabolite of the diuretic drug bumetanide, the 4-[(4'-hydroxy)-phenoxy] analog (7), was identified in incubation mixtures of rat liver microsomes. Phenobarbital and clofibrate pretreatment to induce microsomal enzymes changed the relative amounts of the six metabolites formed. Compound 7was the most prevalent metabolite after clofibrate pretreatment.