Asthma Home > Do My Medications Interfere With Zafirlukast?
Although studies have shown that zafirlukast does not interact with theophylline, there have been reports of increased theophylline blood levels (and side effects) in people who combined zafirlukast with theophylline. If you are taking these drugs together, your healthcare provider may need to monitor the level of theophylline in your blood -- especially when you are starting or stopping zafirlukast.
Taking tolbutamide with zafirlukast can raise the level of tolbutamide in your blood, possibly increasing your risk of side effects. If you are taking these drugs together, your healthcare provider may need to adjust your tolbutamide dosage.
Warfarin (Coumadin, Jantoven)
Taking warfarin with zafirlukast can raise the level of warfarin in your blood, increasing your risk of bleeding. If you are taking these drugs together, your healthcare provider should monitor you very closely and adjust your warfarin dose as necessary when you are starting or stopping zafirlukast.
Not every zafirlukast drug interaction was discussed in this article. Therefore, you should talk with your pharmacist or healthcare provider about specific drug interactions with zafirlukast that may apply to you.