Tell your doctor about all your other medicines, especially:
azathioprine or mercaptopurine;
chlorpropamide;
cyclosporine;
an antibiotic such as ampicillin or amoxicillin;
a blood thinner such as warfarin, Coumadin, Jantoven; or
a diuretic or "water pill".
This list is not complete. Other drugs may interact with allopurinol, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.
 Allopurinol drug interactions (more detail)
