Pitavastatin lactone is the major metabolite of pitavastatin in humans. Pitavastatin is a potent competitive inhibitor of HMG-CoA reductase, which is indicated for hypercholesterolaemia (elevated cholesterol) and for the prevention of cardiovascular disease. Uridine 5’ -diphosphate (UDP) glucuronosyl transferase (UGT) is critically involved in the lactonization of pitavastatin in man and animals. The metabolic and transporter profiles of pitavastatin in man are complex, involving acid/lactone interconversion. Both forms of pitavastatin are observed in-vivo following oral administration. Lactone form and pitavastatin differ in substrate activity towards uptake and efflux transporters.