MedicinePOM

Mercaptopurine

A chemotherapy tablet/suspension used in maintenance treatment of acute lymphoblastic leukaemia.

Clinical information

Common uses

acute lymphoblastic leukaemia (combination maintenance chemotherapy)

Common side effects

low blood counts (anaemia, low white cells, low platelets)
loss of appetite
nausea and vomiting
diarrhoea
rash

Cautions

regular blood count monitoring needed
liver toxicity — liver tests monitored
infection risk — live vaccines are risky
rare aggressive lymphoma has occurred

Interactions

allopurinol — mercaptopurine dose must be reduced
warfarin — anticoagulant effect may fall, monitor INR

Pregnancy: can harm the unborn baby — use effective contraception

Reference information, not medical advice — always follow your doctor or pharmacist. Source: DailyMed, dailymed.nlm.nih.gov, mercaptopurine suspension label, setid 0a366cf3-91f0-4aa4-8f34-a7a27cad8f15 (accessed 2026-08-16)

Approved brands & formulations1

Brand name	Dosage form	Strength	Importer	Category
Mercaptopurine	Tablet	50mg	—	POM