title: Studies on the interaction between fibrates and statins using human hepatic microsomes.
abstract: To gain a better understanding of the mechanism of drug-drug interaction between fibrates and statins, several in vitro experiments were performed. On coincubation with several fibrates, pitavastatin (CAS 147526-32-7) did not displace fibrates from their protein binding in human plasma. The presence of gemfibrozil (CAS 25812-30-0) inhibited the metabolism of statins (cerivastatin (CAS 145599-86-6) and atorvastatin (CAS 134523-00-5)) remarkably. However, the increase of the unchanged form was fairly small for pitavastatin. The metabolic profile of gemfibrozil was also investigated. The cytochrome P (CYP) enzyme CYP2C9 plays a major role in the metabolism of gemfibrozil. Gemfibrozil showed a high affinity for CYP enzymes and a relatively high metabolism velocity. Moreover, several inhibitory effects of gemfibrozil on CYP-mediated metabolism were detected--in contrast to other fibrates. Although the mechanism of the drug-drug interaction was not completely clarified, it is suggested that the increase of plasma concentration caused by the co-administration of gemfibrozil and statins is at least partially due to the inhibition of the CYP-mediated metabolism.
authors.affiliation: Tokyo New Drug Research Laboratories I, Kowa Company Ltd., Higashimurayama, Tokyo, Japan. h-fujino@kowa.co.jp
authors.forename: Hideki
authors.initials: H
authors.lastname: Fujino
authors.forename: Syunsuke
authors.initials: S
authors.lastname: Shimada
authors.forename: Iwao
authors.initials: I
authors.lastname: Yamada
authors.forename: Masaru
authors.initials: M
authors.lastname: Hirano
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Tsunenari
authors.forename: Junji
authors.initials: J
authors.lastname: Kojima
mesh_terms: D019138:Antibodies, Blocking / Q000494:pharmacology; D001798:Blood Proteins / Q000378:metabolism; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004347:Drug Interactions; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000378:metabolism*; D000960:Hypolipidemic Agents / Q000494:pharmacology*; D066298:In Vitro Techniques; D008862:Microsomes, Liver / Q000187:drug effects*; D011485:Protein Binding
chemical_list: D019138:Antibodies, Blocking; D001798:Blood Proteins; D065607:Cytochrome P-450 Enzyme Inhibitors; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D000960:Hypolipidemic Agents; D003577:Cytochrome P-450 Enzyme System