Effects of cilostazol on the pharmacokinetics of carvedilol after oral and intravenous administration in rats.
This study was designed to investigate the effects of cilostazol on the pharmacokinetics of carvedilol following oral or intravenous administration of carvedilol in rats. Clinically carvedilol and cilostazol can be prescribed for treatment of cardiovascular diseases. Carvedilol and cilostazol are all substrates of CYP2C9 enzymes. Carvedilol was administered orally or intravenously without or with oral administration of cilostazol to rats. The effects of cilostazol on cytochrome P450 (CYP) 2C9 activity and P-gp activity were also evaluated. Cilostazol inhibited CYP2C9 activity in a concentration-dependent manner with 50% inhibitory concentration (IC(50)) of 8.7 μM. Compared with the control group, the area under the plasma concentration-time curve (AUC) of carvedilol was significantly (P < 0.05) increased by 38.0%. The peak concentration (C(max)) was significantly (P < 0.05) increased by 49.2% in the presence of cilostazol after oral administration of carvedilol. Consequently, the relative bioavailability (R.B.) of carvedilol was increased by 1.15 - 1.38-fold, and the absolute bioavailability (A.B.) of carvedilol in the presence of cilostazol was significantly (P < 0.05) higher than that of the control. After intravenous administration, the AUC of carvedilol was significantly (P < 0.05) increased by 19.2% compared to that in the control by cilostazol. These results suggest that cilostazol effectively inhibited the metabolism of carvedilol. The increased oral bioavailability of carvedilol might be due to the inhibition of CYP2C9-mediated metabolism of carvedilol in the liver by cilostazol.
Department of Pharmacy, Chosun University Hospital, Gwangju, Republic of Korea.
T H
TH
Lim
Biomedical Research Institute, Kyeongsang National University Hospital, Jinju, Republic of Korea.
Y A
YA
Cho
Department of Internal Medicine, School of Medicine, Chosun University, Gwangju, Republic of Korea. dhchoi@chosun.ac.kr.
D H
DH
Choi
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000284:Administration, Oral; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000818:Animals; D019540:Area Under Curve; D001682:Biological Availability; D002227:Carbazoles / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000077261:Carvedilol; D000077407:Cilostazol; D065688:Cytochrome P-450 CYP2C9 Inhibitors / Q000494:pharmacology; D003577:Cytochrome P-450 Enzyme System / Q000187:drug effects; D004347:Drug Interactions; D006207:Half-Life; D007275:Injections, Intravenous; D008297:Male; D011412:Propanolamines / Q000008:administration & dosage / Q000493:pharmacokinetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013777:Tetrazoles / Q000008:administration & dosage / Q000494:pharmacology*; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000494:pharmacology*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000319:Adrenergic beta-Antagonists; D002227:Carbazoles; D065688:Cytochrome P-450 CYP2C9 Inhibitors; D011412:Propanolamines; D013777:Tetrazoles; D014665:Vasodilator Agents; D000077261:Carvedilol; D003577:Cytochrome P-450 Enzyme System; C507848:CYP2C9 protein, rat; D000077407:Cilostazol