Azathioprine Mercaptopurine
ModerateThe leaflet text does not say how azathioprine and mercaptopurine act on each other. It only says that when allopurinol, oxipurinol or thiopurinol is given with 6-mercaptopurine or azathioprine, the dose of each should be cut to 25% of the original dose.
These medicines are often taken together with some care. Your doctor may change a dose, space them apart or check on you more often. Make sure your doctor and pharmacist know you take both.