Azathioprine (INN, /ˌæzəˈθaɪɵpriːn/, abbreviated AZA) is an immunosuppressive drug used in organ transplantation and autoimmune diseases and belongs to the chemical class of purine analogues. Synthesized originally as a cancer drug and a pro-drug for mercaptopurine in 1957, it has been widely used as a immunosuppressant for more than 50 years.
Azathioprine acts as a pro-drug for mercaptopurine, inhibiting an enzyme that is required for the synthesis of DNA. Thus it most strongly affects proliferating cells, such as the T cells and B cells of the immune system.
The main adverse effect of azathioprine is bone marrow suppression, which can be life-threatening, especially in people with a genetic deficiency of the enzyme thiopurine S-methyltransferase. It is also listed by the International Agency for Research on Cancer as a Group 1 carcinogen (carcinogenic to humans).
Azathioprine is produced by a number of manufacturers under different brand names (Azasan by Salix in the U.S., Imuran by GlaxoSmithKline in Canada, the U.S., Australia, Ireland and Great Britain, Azamun in Finland and Imurel in Scandinavia and France, among others).
Read more about Azathioprine: Medical Uses, Adverse Effects, Overdose, Pregnancy and Breastfeeding, Pharmacokinetics, Mechanism of Action, Physical and Chemical Properties, History