oconazole) [see Warnings and Precautions (5.2), Clinical Pharmacology (12.3)]. The effects of concomitant administration of a moderate CYP2D6 inhibitor (e.g., terbinafine) on the pharmacokinetics of tamsulosin have not been eva luated [see Warnings and Precautions (5.2), Clinical Pharmacology (12.3)]. The effects of coadministration of both a CYP3A4 and a CYP2D6 inhibitor with tamsulosin have not been eva luated. However, there is a potential for significant increase in tamsulosin exposure when tamsulosin 0.4 mg is coadministered with a combination of both CYP3A4 and CYP2D6 inhibitors [see Warnings and Precautions (5.2), Clinical Pharmacology (12.3)].
Cimetidine: Treatment with cimetidine resulted in a significant decrease (26%) in the clearance of tamsulosin hydrochloride, which resulted in a moderate increase in tamsulosin hydrochloride AUC (44%) [see Warnings and Precautions (5.2), Clinical Pharmacology (12.3)].
Tamsulosin-containing products, including JALYN, should not be used in combination with other alpha-adrenergic antagonists. The pharmacokinetic and pharmacodynamic interactions between tamsulosin and other alpha-adrenergic antagonists have not been determined. However, interactions may be expected [see Warnings and Precautions (5.2), Clinical Pharmacology (12.3)].
Caution is advised when alpha-adrenergic antagonists, including tamsulosin-containing products such as JALYN, are coadministered with PDE-5 inhibitors. Alpha-adrenergic antagonists and PDE-5 inhibitors are both vasodilators that can lower blood pressure. Concomitant use of these 2 drug classes can potentially cause symptomatic hypotension [see Warnings and Precautions (5.2), Clinical Pharmacology (12.3)].
Dutasteride: 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 [see Clinical Pharmacology (12.3)].
Tamsulosin: A definitive drug-drug interaction study between tamsulosin hydrochloride and warfarin was not conducted. Results from limited in vitro and in vivo studies are inconclusive. Caution should be exercised with concomitant administration of warfarin and tamsulosin-containing products, including JALYN [see Warnings and Precautions (5.2), Clinical Pharmacology (12.3)].
Tamsulosin: Dosage adjustments are not necessary when tamsulosin is administered concomitantly with nifedipine, atenolol, or enalapril [see Clinical Pharmacology (12.3)].
Dutasteride: Dutasteride does not alter the steady-state pharmacokinetics of digoxin when administered concomitantly at a dose of 0.5 mg/day for 3 weeks [see Clinical Pharmacology (12.3)].
Tamsulosin: Dosage adjustments are not necessary when tamsulosin is administered concomitantly with digoxin or theophylline [see Clinical Pharmacology (12.3)].
Tamsulosin: Tamsulosin had no effect on the pharmacodynamics (excretion of electrolytes) of furosemide. While furosemide produced an 11% to 12% reduction in tamsulosin hydrochloride C and AUC, these changes are expected to be clinically insignificant and do not require adjustment of the dose of tamsulosin [see Clinical Pharmacology (12.3)].
Dutasteride: Coadministration of verapamil or diltiazem decreases dutasteride clearance and leads to increased exposure to dutasteride. However, th
