IBD

Question 1

Indications for azathioprine

Answer 1

• IBD
• DMARD for RA and other autoimmune conditions
• prevent organ rejection in transplant recipients

Question 2

Azathioprine MOA

Answer 2

= pro drug
Main metabolite - 6 mercaptopurine. Its also metabolised and these inhibit synthesis of purines esp adenine and guanine. And so inhibit RNA replication.

Most cells recycle purines, lymphocytes depend on this .

Metabolisism and elimination are dependant on xanthine oxidase and TPMT. Some people naturally have less TPMT

Question 3

SE azathioprine

Answer 3

BM supression = leukopenia and increased risk of infection. Reduce dose or take break to tackle.
Can do TPMT phenotype to identify the at risk

Nausea -reduce by dividing daily dose

Hypersensitivity reactions - D and V, rash, fever, myalgia, hypotension and pancreatitis

Veno occlusive disease
Hepatotoxic
Risk of lymphoma

Question 4

Azathioprine CI

Answer 4

• absent TPMT activity
• hypersensitivity reactions
• teratogen but can continue if v necessary

reduce dose in

• less TPMT activity
• renal and hepatic impairment

Question 5

interactions of azathioprine

Answer 5

• risk of infection if use with other supressants e.g. steroids.
• do not prescribe with xanthine oxidase-i
• risk of leukopenia if with other myelosupressive drugs = trimethoprim
• reduces effect of warfarin

Question 6

how is azathioprine prescribed

Answer 6

1-3mg/kg dailuy in divided doses

Question 7

monitoring azathioprine

Answer 7

• FBC weekly for first 4 weeks or after dose change and 3 monthly after.

Question 8

can a fy1 start immunosupressants

Answer 8

no