trans-hydroxyGlimepiride is an active metabolite of the sulfonylurea glimepiride .1It is formed from glimepiride primarily in the liver by the cytochrome P450 (CYP) isoform CYP2C9. 1.Langtry, H.D., and Balfour, J.A.Glimepiride. A review of its use in the management of type 2 diabetes mellitusDrugs55(4)563-584(1998)