Mercaptopurine: how to take it safely
Purinethol
Reviewed by Pharm. Abeeb Junior
What it is for
Treats acute lymphoblastic leukaemia (ALL) and is used in Crohn's disease and ulcerative colitis.
How to take it
- Prescription medicine: take it exactly as your doctor or pharmacist told you.
- Swallow with water. Do not crush.
- You will need regular blood tests.
When to take it
Take it once a day, in the evening, at the same time.
Take it with
On an empty stomach, or at least 1 hour before or 2 hours after milk.
What to avoid
- Milk and dairy within 1 hour of the dose.
- Allopurinol, unless your doctor lowers your dose.
- Missing blood tests.
- Pregnancy.
- Strong sunlight. Use sunscreen.
- Live vaccines unless your cancer team says so.
- Contact with people who have infections such as chickenpox or flu.
- Alcohol, unless your team says it is safe.
Possible side effects
Nausea, loss of appetite, rash, low blood counts, raised liver tests.
Get help if
Fever, sore throat, unusual bruising or bleeding, yellow skin or eyes, or severe stomach pain: get urgent help.
This is general information, not personal medical advice. Always follow your doctor's or pharmacist's instructions and read the leaflet that comes with your medicine. Medicines and doses can differ between products and people.