Hi I have just been prescribed 250mg of erythromycin for acne. i was just wondering if this may interact with the warfarin i am taking. The leaflet says there may be interaction with it, any thoughts?
Check your INR in 3 days. It's going to rise, but how much is the question. For future reference when you need to check interactions, copy this link to your favorites:
WARFARIN SODIUM (in Coumadin) may interact with ERYTHROMYCIN (in Erythromycin Tablets, Capsules, and Extended-Release)
Erythromycin may block the breakdown of warfarin by the liver. If this happens, blood levels of warfarin could be increased and this could increase its anticoagulant effect. Warfarin is generally used to prevent your blood from "coagulating" or forming blood clots. When erythromycin and warfarin are used at the same time, your blood may be much less likely to clot and this may increase the risk of excessive bleeding. If these drugs are taken together, your doctor may want to monitor you closely when therapy with erythromycin is either started or stopped. Blood tests can be used to make sure that you are getting the right amount of warfarin. If you are experiencing problems, it may be necessary to adjust the dose of warfarin. Ask your healthcare provider about these drugs and this potential interaction as soon as possible.
This interaction is well-documented and is considered major in severity.