Formulation:
Injection 25mg
Tablet 25mg, 50mg

Dose:
PO/IV 1-3mg/kg

Dose between 2-3mg per kilogram is used, sometimes with initial 5 day intravenous duration.
Manipulate oral dose to multiples of 25mg if possible to save handling broken or crushed tablets.

Side-effects:
Hypersensitivity, dizziness, fever, rigors, muscular pain, disturbed LFT’s and hypotension. STOP DRUG
Bone marrow suppression – dose related.
FBC weekly for first eight weeks then decrease to monthly for 3 months and then to 3 monthly

Interactions:
Reduce dose of azathioprine by 25% if on concomittant allopurinol.
Manufacturers report interaction with rifampacin.

Notes:
Thought that 5 day course of IV azathioprine will put patient into remission earlier than 4 to 6 weeks if course is started with oral medication.
Infuse IV dose in dextrose/saline over 1-3 hours.
Each patient on Azathioprine and their GP and, if appropriate Paediatrician, will receive an Azathioprine protocol sheet detailing side effects and investigations such as blood tests