Ketoconazole Inhibition of Gepirone Biotransformation and Clearance: In Vitro and Clinical Studies.

Gepirone, an antidepressant drug, is biotransformed into two principal metabolites [1-(2-pyrimidinyl)-piperazine (1-PP) and 3'-OH-gepirone] primarily by CYP3A enzymes. Metabolism of gepirone in the presence of ketoconazole, a potent inhibitor of human CYP3A activity, was studied in vitro in human liver microsomes. The clinical pharmacokinetic interaction of ketoconazole (as a maximal chemical inhibitor of CYP3A isoforms) with single doses of gepirone was evaluated in a Phase 1 study in human volunteers (N = 24).

Mechanism of dasabuvir inhibition of acetaminophen glucuronidation.

Objectives: Acetaminophen (APAP) (paracetamol) is a widely used non-prescription drug for pain relief and antipyretic effects. The clearance of APAP is mainly through phase-2 biotransformation catalysed by UDP-glucuronosyl transferases (UGT). Dasabuvir is an anti-hepatitis C drug reported to inhibit several UGT isoforms.