Mechanism of Action of Azathioprine Drug causes a greater suppression of delayed hypersensitivity and cellular cytotoxicity. Drug also antagonizes purine metabolism (necessary for proliferation of cells especially for leukocytes and lymphocytes) and may inhibit the synthesis of DNA, RNA and proteins. It may also inhibit the cellular metabolism and inhibit mitosis. Indications for Azathioprine 1. Ulcerative colitis 2. To prevent rejection of kidney transplants 3. Rheumatoid arthritis 4. Crohn`s disease 5. Cirrhosis 6. Dermatomyositis 7. Hepatitis C 8. Lupus erythematosus 9. Myasthenia gravis 10. Myopathy 11. Nephritic syndrome 12. Pemphigoid 13. Pemphigus 14. Atopic dermatitis 15. Cutaneous polyarteritis nodosa 16. Cutaneous vasculitis 17. Immune mediated hemolytic anemia 18. Immune mediated platelet destruction