ic Populations (8.6)].
Hepatic Impairment: The pharmacokinetics of UROXATRAL have not been studied in patients with mild hepatic impairment. In patients with moderate or severe hepatic insufficiency (Child-Pugh categories B and C), the plasma apparent clearance (CL/F) was reduced to approximately one-third to one-fourth that observed in healthy subjects. This reduction in clearance results in three to four-fold higher plasma concentrations of alfuzosin in these patients compared to healthy subjects. Therefore, UROXATRAL is contraindicated in patients with moderate to severe hepatic impairment [see Contraindications (4), Warnings and Precautions (5.3) and Use in Specific Populations (8.7)].
Pediatric Use: UROXATRAL tablets are not indicated for use in the pediatric population [see Indications and Usage (1.1) and Use in Specific Populations (8.4)].
Drug-Drug Interactions
Metabolic Interactions
CYP3A4 is the principal hepatic enzyme isoform involved in the metabolism of alfuzosin.
Potent CYP3A4 Inhibitors
Repeated oral administration of 400 mg/day of ketoconazole, a potent inhibitor of CYP3A4, increased alfuzosin Cmax by 2.3-fold and AUClast by 3.2-fold, following a single 10 mg dose of alfuzosin.
In another study, repeated oral administration of a lower (200 mg/day) dose of ketoconazole increased alfuzosin Cmax by 2.1-fold and AUClast by 2.5-fold, following a single 10 mg dose of alfuzosin.
Therefore, UROXATRAL is contraindicated for co-administration with potent inhibitors of CYP3A4 (e.g., ketoconazole, itraconazole, or ritonavir) because of increased alfuzosin exposure[see Contraindications (4), Warnings and Precautions (5.4) and Drug Interactions (7.1)].
Moderate CYP3A4 Inhibitors
Diltiazem: Repeated co-administration of 240 mg/day of diltiazem, a moderately-potent inhibitor of CYP3A4, with 7.5 mg/day (2.5 mg three times daily) alfuzosin (equivalent to the exposure with UROXATRAL) increased the Cmax and AUC0–24 of alfuzosin 1.5- and 1.3-fold, respectively. Alfuzosin increased the Cmax and AUC0–12 of diltiazem 1.4-fold. Although no changes in blood pressure were observed in this study, diltiazem is an antihypertensive medication and the combination of UROXATRAL and antihypertensive medications has the potential to cause hypotension in some patients [see Warnings and Precautions (5.1)].
In human liver microsomes, at concentrations that are achieved at the therapeutic dose, alfuzosin did not inhibit CYP1A2, 2A6, 2C9, 2C19, 2D6 or 3A4 isoenzymes. In primary culture of human hepatocytes, alfuzosin did not induce CYP1A, 2A6 or 3A4 isoenzymes.
Other Interactions
Warfarin: Multiple dose administration of an immediate release tablet formulation of alfuzosin 5 mg twice daily for six days to six healthy male volunteers did not affect the pharmacological response to a single 25 mg oral dose of warfarin.
Digoxin: Repeated co-administration of UROXATRAL 10 mg tablets and digoxin 0.25 mg/day for 7 days did not influence the steady-state pharmacokinetics of either drug.
Cimetidine: Repeated administration of 1 g/day cimetidine increased both alfuzosin Cmax and AUC values by 20%.
Atenolol: Single administration of 100 mg atenolol with a single dose of 2.5 mg of an immediate release alfuzosin tablet in eight healthy young male volunteers increased alfuzosin Cmax and AUC values by 28% and 21%, respectively. Alfuzosin increased atenolol Cmax and AUC values by 26% and 14%, respective |
