Dutarid Drug Interactions

Cytochrome P450 3A Inhibitors: Dutasteride is extensively metabolized in humans by the CYP3A4 and CYP3A5 isoenzymes. The effect of potent CYP3A4 inhibitors on Dutasteride has not been studied. Because of the potential for drug-drug interactions, use in caution when prescribing Dutasteride to patients taking potent, chronic CYP3A4 enzyme inhibitors (e.g., ritonavir).
Alpha-adrenergic Antagonists: The administration of Dutasteride in combination with tamsulosin or terazosin has no effect on the steady-state pharmacokinetics of either alpha-adrenergic antagonist. The effect of administration of tamsulosin or terazosin on dutasteride pharmacokinetic parameters has not been evaluated.
Calcium Channel Antagonists: Co-administration of verapamil or diltiazem decreases Dutasteride clearance and leads to increased exposure to Dutasteride. The change in Dutasteride exposure is not considered to be clinically significant. No dose adjustment is recommended.
Cholestyramine: Administration of a single 5-mg dose of Dutasteride followed 1 hour later by 12 g of cholestyramine does not affect the relative bioavailability of Dutasteride.
Digoxin: Dutasteride does not alter the steady-state pharmacokinetics of digoxin when administered concomitantly at a dose of 0.5 mg/day for 3 weeks.
Warfarin: Concomitant administration of Dutasteride 0.5 mg/day for 3 weeks with warfarin does not alter the steady-state pharmacokinetics of the S- or R-warfarin isomers or alter the effect of warfarin on prothrombin time.