Cytotoxic agents, immunosuppressive action

Cytotoxic agents which are exclusively used to achieve immunosuppression are azathioprine and mycophenolate mofetil, although their over all mechanism of action is similar to that of the antitumor dmgs, i.e. inhibition of lymphocyte proliferation after antigen exposure. 

DNA s5mthesis and also interfere with cell replication. Alkylating agents has got cytotoxic action and damage the nuclei of growing and multiplying cells. They have got immunosuppressant action also and suppress antibody production. They also have radiomimetic (like ionizing radiation) actions. 

Azathioprine is a prodrug of mercaptopurine and, like mercaptopurine, functions as an antimetabolite (see Chapter 54). Although its action is presumably mediated by conversion to mercaptopurine and further metabolites, it has been more widely used than mercaptopurine for immunosuppression in humans. These agents represent prototypes of the antimetabolite group of cytotoxic immunosuppressive drugs, and many other agents that kill proliferative cells appear to work at a similar level in the immune response. 

---