Use with Allopurinol: The principal pathway for detoxification of azathioprine is inhibited by
allopurinol. Patients receiving azathioprine and allopurinol concomitantly should have a dose reduction of
azathioprine, to approximately 1/3 to 1/4 the usual dose.
Use with Other Agents Affecting Myelopoesis: Drugs which may affect leukocyte production, including
co-trimoxazole, may lead to exaggerated leukopenia, especially in renal transplant recipients.
Use with Angiotensln Converting Enzyme Inhibitors: The use of angiotensin converting enzyme
inhibitors to control hypertension in patients on azathioprine has been reported to induce severe leukopenia.