Azathioprine occurs as chemotherapy drug, now seldom utilized for chemotherapy however thomas more for immunosuppression in organ transplantation and autoimmune disease such as rheumatoid arthritis or Crohn's disease. These are the pro-drug, converted in the body to the active metabolite 6-mercaptopurine.

Azathioprine was number one introduced into clinical practice by Sir Roy Calne, the British pioneer within transplantation. Ensuing a act treat Sir Peter Medawar in discovering the immunologic basis of rejection of transplanted tissues and organs, Calne introduced 6-mercaptopurine as an experimental immunosuppressive for kidney transplants. After imuran was found, he so introduced it as a less toxic replacement for 6-mercaptopurine. For several years, dual therapy using imuran & steroids was a standard anti-rejection regime, until cyclosporine was introduced into clinical practice (also by Calne) around 1978.

Azathioprine acts to inhibit purine synthesis necessary for the proliferation of cells, especially leukocytes and lymphocytes. These are the safe & effectual drug utilized alone around certawithinside autoimmune disorder, or even in combination by having more immunosuppressants in organ transplantation. Its virtually all severe side result is bone marrow suppression, and it should non become given within conjunction by owning purine parallel like allopurinol. A enzyme thiopurine S-methyltransferase (TPMT) deactivates 6-mercaptopurine. Genetic polymorphisms of TPMT can lead to excessive drug toxicity, thus assay of blood serum TPMT can be utile to cease this complication.

Mycophenolate mofetil is increasingly existence utilized within situ of imuran in organ transplantation, however imuran surely however has the major role.

Reference
Konstantopoulou M, Belgi The, Griffiths KD, Seale JR, Macfarlane AW. Azathioprine-caused pancytopenithe around a patient by using pompholyx & deficiency of red blood cell thiopurine methyltransferase. BMJ 2005;330:350-1. PMID 15705694.