 The major metabolite of trilostane is 17-ketotrilostane.The conversion of trilostane into 17-ketotrilostane is reversible, suggesting that trilostane and 17-ketotrilostane undergo interconversion in the body.17-Ketotrilostane circulates at 3-fold higher levels than trilostane and is more active than trilostane as a 3β-HSD inhibitor.