Abstract

Azathioprine (Imuran - BW) is a purine analogue which blocks the incorporation of natural purines into DNA and thereby inhibits cell division. The drug is converted to 6-mercaptopurine and then to one or more further active metabolites. Its main use over the past decade has been to suppress allograft rejection, particularly after renal transplantation. It is now being tried as an alternative or adjunct to corticosteroids to suppress chronic inflammatory disorders of unknown cause, such as Crohn’s disease, ulcerative colitis, rheumatoid arthritis, systemic lupus erythematosus and some forms of chronic hepatitis. Crohn’s disease is probably an immunological disorder either of the hypersensitive or of the immuno-incompetent variety.