azathioprine

see also:

• pharmacology main index
• immunosuppressants
• Crohn's disease

• azathioprine (Imuran) is a imidazole 6-mercaptupurine derivative immunosuppressant.

• Crohn's disease
• transplant recipients
• severe RA
• systemic lupus erythematosus (SLE)
• dermatomyositis
• autoimmune chronic active hepatitis
• pemphigus vulgaris
• polyarteritis nodosa (PAN)
• autoimmune haemolytic anaemia
• chronic refractory ITP

• hypersensitivity
• bone marrow suppression
• alopecia
• pancreatitis
• hepatotoxicity
• cholestasis
• gastrointestinal upset
• increased risk of infections
• increased risk of neoplasia / cancer / tumours such as skin cancer, lymphoma
• Stevens-Johnson syndrome and toxic epidermal necrolysis
• very rarely, pneumonitis

• hypersensitivity to 6-MP
• previous rheumatoid arthritis Rx with alkylating agents
• live vaccines
• pregnancy

• monitor FBE, LFT
• possible neoplasia / cancer / tumours potential - esp. watch for skin cancers (and minimise UV exposure), cervical cancer and non-Hodgkin's lymphoma
• avoid pregnancy (including while males are on Rx)
• avoid exposure to varicella virus
• avoid abrupt withdrawal
• care in renal/hepatic impairment
• care in dental Rx as bacteraemia risk
• hypersplenism, myasthenia, dermatomyositis, lactation, Lesch-Nyhan syndrome.

• should be taken with food
• tablets are usually 50mg in packs of 100
• transplantation dose: up to 5mg/kg initial dose then 1-4mg/kg/day maintenance
• other indications: initially 1mg/kg/day and increase slowly over several weeks by 0.5mg/kg/day as needed to max. 2.5mg/kg/day
• lower dose in elderly

• usually only used when oral dosing impractical.
• slow iv or infusion