Montelukast drug interactions

List of drug interactions
10 mg daily dose ≥100 mg daily dose Phenobarbital/rifampin Rosiglitazone
 * Warfarin
 * Theophylline
 * Digoxin
 * Terfenadine/fexofenadine
 * Norethindrone/ethinyl estradiol
 * Prednisone/prednisolone

Warfarin
Montelukast at a dose of 10 mg once daily dosed to pharmacokinetic steady state did not change the pharmacokinetic profile of warfarin (primarily a substrate of CYP 2C9, 3A4 and 1A2) or influence the effect of a single 30-mg oral dose of warfarin on prothrombin time or the INR (International Normalized Ratio). Return to top

Theophylline
Montelukast at a dose of 10 mg once daily dosed to pharmacokinetic steady state did not cause clinically significant changes in the kinetics of a single intravenous dose of theophylline (predominantly a cytochrome P450 1A2 substrate). Return to top

Digoxin
Montelukast at a dose of 10 mg once daily dosed to pharmacokinetic steady state did not change the pharmacokinetic profile or urinary excretion of immunoreactive digoxin. Return to top

Terfenadine/fexofenadine
Montelukast at a dose of 10 mg once daily dosed to pharmacokinetic steady state did not change the plasma concentration profile of terfenadine (a substrate of CYP 3A4) or fexofenadine, its carboxylated metabolite, and did not prolong the QTc interval following co-administration with terfenadine 60 mg twice daily. Return to top

Norethindrone/ethinyl estradiol
Montelukast at doses of ≥100 mg daily dosed to pharmacokinetic steady state did not significantly alter the plasma concentrations of either component of an oral contraceptive containing norethindrone 1 mg/ethinyl estradiol 35 mcg. Return to top

Prednisone/prednisolone
Montelukast at doses of ≥100 mg daily dosed to pharmacokinetic steady state did not cause any clinically significant change in plasma profiles of prednisone or prednisolone following administration of either oral prednisone or intravenous prednisolone. Return to top

Phenobarbital/rifampin
Phenobarbital, which induces hepatic metabolism, decreased the AUC of montelukast approximately 40% following a single 10-mg dose of montelukast. No dosage adjustment for Montelukast is recommended. It is reasonable to employ appropriate clinical monitoring when potent cytochrome P450 enzyme inducers, such as phenobarbital or rifampin, are co-administered with Montelukast. Return to top

Rosiglitazone
Montelukast is a potent inhibitor of P450 2C8 in vitro. However, data from a clinical drug-drug interaction study involving montelukast and rosiglitazone (a probe substrate representative of drugs primarily metabolized by CYP2C8) in 12 healthy individuals demonstrated that the pharmacokinetics of rosiglitazone are not altered when the drugs are coadministered, indicating that montelukast does not inhibit CYP2C8 in vivo. Therefore, montelukast is not anticipated to alter the metabolism of drugs metabolized by this enzyme (e.g., paclitaxel, rosiglitazone, and repaglinide). Return to top