Moderate. These medicines may cause some risk when taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
When you take these two medicines together, zafirlukast may increase the effects of warfarin.
What might happen:
You may experience an increased chance of bleeding including bleeding from your gums, nosebleeds, unusual bruising, or dark stools.
What you should do about this interaction:
Contact your healthcare professionals (e.g. doctor of pharmacist) about taking these medicines together. If your doctor prescribed these medicines together, you may need to check your bleeding times more often. Your doctor may need to adjust your dose of warfarin.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
1.Accolate (zafirlukast) US prescribing information. AstraZeneca Pharmaceuticals LP August, 2011.
2.Singulair (montelukast) US prescribing information. Merck & Co., Inc. October, 2012.