Drug Information

Zafirlukast is used in the prevention and treatment of mild to severe asthma, seasonal allergic asthma, exercise-induced asthma, and aspirin-induced asthma. It belongs to a class of drugs called leukotriene-receptor antagonists (LTRA).

Common brand names:


Summary of Interactions with Vitamins, Herbs, & Foods

Types of interactions: Beneficial Adverse Check

Replenish Depleted Nutrients

  • none

Reduce Side Effects

  • none

Support Medicine

  • none

Reduces Effectiveness

  • none

Potential Negative Interaction

  • White Willow

    Willow bark (Salix alba) contains salicin, a substance similar to aspirin. Research has shown that aspirin significantly increases blood levels of zafirlukast,1 which would increase the likelihood of side effects from zafirlukast. The same thing could theoretically happen if people took willow bark along with zafirlukast, although no studies have investigated this specific interaction. People may want to avoid combining willow bark with zafirlukast due to the possibility of increased side effects.

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Explanation Required 

  • none

The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers’ package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a new supplement with your doctor or pharmacist.


1. Kelloway JS. Zafirlukast: the first leukotriene-receptor antagonist approved for the treatment of asthma. Ann Pharmacother 1997;31(9):1012-21.