Montelukast may be administered with other therapies routinely used in the prophylaxis and chronic treatment of asthma.
The recommended clinical dose of Montelukast does not have clinically important effects on the pharmacokinetics of the following drugs: Theophylline, Prednisone, Prednisolone, oral contraceptives (Ethinyl estradiol/ Norethindrone 35/1), Terfenadine, Digoxin and Warfarin.
Since Montelukast is metabolized by CYP 3A4, caution should be exercised, particularly in children, when Montelukast is co-administered with inducers of CYP 3A4, such as Phenytoin, Phenobarbital and Rifampicin. Montelukast is not anticipated to markedly alter the metabolism of drugs metabolized by this enzyme (e.g. Paclitaxel, Rosiglitazone, and Repaglinide).