This site is intended for UK healthcare professionals
Medscape UK Univadis Logo
Medscape UK Univadis Logo


Oral formulations of mercaptopurine.

Drugs List

  • HANIXOL 50mg tablets
  • mercaptopurine 20mg/1ml oral suspension
  • mercaptopurine 50mg tablets
  • XALUPRINE 20mg/1ml oral suspension
  • Therapeutic Indications


    Leukaemia - acute lymphoblastic
    Leukaemia - acute myeloid
    Leukaemia - acute promyelocytic

    Unlicensed Uses

    Crohn's disease - maintenance of remission
    Severe Crohn's disease
    Ulcerative colitis: induction of remission
    Ulcerative colitis: maintenance of remission


    Whilst the doses stated below are those recommended by the manufacturer, local cancer network protocols for the relevant indication should be consulted.

    Doses may vary significantly if this agent is used as monotherapy or different combinations.

    When using this agent, specialist literature, national guidelines, cancer networks protocols and Trust chemotherapy protocols should be consulted.


    Initial dose: 2.5mg/kg daily, or 25 to 75mg/square metre body surface area daily.
    Dose should be adjusted according to individual patient response.

    Inflammatory bowel disease (unlicensed)
    1mg/kg to 1.5mg/kg daily, although lower doses may be sufficient in some patients.


    Initial dose: 2.5mg/kg daily, or 25 to 75mg/square metre body surface area daily.
    Dose should be adjusted according to individual patient response.

    Inflammatory bowel disease (unlicensed)
    Children aged 2 to 18 years
    1mg/kg to 1.5mg/kg daily (maximum 50mg per dose). Can then be increased to 75mg once daily if required. Lower doses may be sufficient in some patients.


    Administration of daily dose should be in the evening as this may lower the risk of relapse.



    Precautions and Warnings

    Inherited thiopurine methyltransferase deficiency
    Glucose-galactose malabsorption syndrome
    Hepatic impairment
    Hereditary fructose intolerance
    Lactose intolerance
    Renal impairment - creatinine clearance below 50ml/minute

    Administration of live vaccines is not recommended
    Some formulations contain aspartame - caution in phenylketonuria
    Not all available brands are licensed for all indications
    Not all formulations are licensed for all uses
    Treatment to be initiated and supervised by a specialist
    Oral solution contains sucrose and hydroxybenzoates
    Some formulations contain lactose
    Some formulations contain sucrose
    Different formulations are not bioequivalent
    Monitor closely if switching between tablet formulation and oral solution
    Accidental contact of soln with skin/mucous membranes-rinse well with water
    Avoid contact with mucous membranes
    Avoid contact with skin or eyes
    Consult local policy on the safe use of oral anti-cancer drugs
    Staff: Not to be handled by pregnant staff
    Take at the same time in respect to food as absorption may be affected
    Monitor haematological parameters before and during treatment
    Elderly: Monitor renal function and consider dose modification
    Monitor for presence of hepatitis B markers
    Monitor for signs of Macrophage Activation Syndrome (MAS)
    Monitor liver function tests weekly
    Monitor patients for signs of tumour lysis syndrome
    Monitor patients receiving concurrent anticoagulants
    Monitor renal function regularly
    Monitor uric acid levels
    Advise patient to report unexplained fever, sore throat, bruising, bleeding
    Consider treatments to prevent hyperuricaemia
    Potentially mutagenic and carcinogenic
    Risk of developing opportunistic infections
    Discontinue at first signs of jaundice
    Discontinue if Macrophage Activation Syndrome is suspected
    Discontinue immediately if any severe fall in blood counts occur
    Consider dose reduction in hepatic impairment
    Consider dose reduction in renal impairment
    Reduce dose to 25% of normal when given with allopurinol
    Advise patient to avoid dairy products 1 hour before and 2 hours after dose
    Male & female: Contraception required during & for 3 months after treatment
    Advise patient to avoid exposure to sunlight and UV rays during treatment
    Advise patient to use SPF 50+ sunscreen and lip balm during treatment

    Individuals with an inherited deficiency of the enzyme thiopurine methyltransferase (TPMT) may be unusually sensitive to the myelosuppressive effect of tioguanine and prone to developing rapid bone marrow depression following initiation of treatment with tioguanine. This problem could be exacerbated by co-administration with drugs that inhibit TPMT.

    Individuals with inherited mutated NUDT15 gene are at increased risk of severe 6-mercaptopurine toxicity. Patients with NUDT15 variant generally require dose reduction of mercaptopurine, particularly individuals that are NUDT15 homozygotes.

    During remission induction in acute myelogenous leukaemia the patient may frequently experience a period of relative bone marrow aplasia and it is important that adequate supportive facilities are available.

    Adequate precautions should be taken to avoid hyperuricaemia, hyperuricosuria and uric acid nephropathy during remission induction, especially when rapid cell lysis is occurring.

    Macrophage Activation Syndrome (MAS) is a known, life-threatening disorder that may develop in patients with autoimmune conditions. If MAS occurs, or is suspected, evaluation and treatment should be started as early as possible. Physicians should be attentive to the symptoms of infection as this is a known trigger for MAS.

    Pregnancy and Lactation


    Mercaptopurine is contraindicated during pregnancy.

    The manufacturers recommend avoiding mercaptopurine during pregnancy.

    Mercaptopurine is an active metabolite of azathioprine. Mercaptopurine is potentially carcinogenic and mutagenic; prematurity and malformation have been reported, although there are also reports of normal outcomes when the mother has taken mercaptopurine during pregnancy.

    In any individual case the potential hazard to the foetus must be balanced against the expected benefit to the mother.

    The effect of concurrent therapies must also be considered.


    Mercaptopurine is contraindicated during breastfeeding.

    The manufacturers recommend avoiding mercaptopurine during breastfeeding.

    Mercaptopurine has been detected in the breast milk of patients receiving immunosuppressive therapy with azathioprine, a pro-drug of mercaptopurine.

    Due to the molecular weight of mercaptopurine excretion into the breast milk is to be expected. There is some evidence of the risk to the infant but in consideration of the known side effects extreme caution would be advised. If administered the infants complete blood count and liver function should be closely monitored. Infants with the rare deficiency of thiopurine-methyltransferase (TPMT) could be sensitive to maternal long-term therapy while being breastfed.

    The effect of concurrent therapies must also be considered.

    Side Effects

    Biliary stasis
    Bone marrow depression
    Drug fever
    Facial oedema
    Gastro-intestinal ulceration
    Hepatic necrosis
    Hepatic veno-occlusive disease
    Kaposi's Sarcoma
    Lymphoproliferative disorders
    Malignant melanoma
    Mouth ulcers
    Myelodysplastic syndrome
    Nodular regenerative hyperplasia
    Non Kaposi's sarcoma
    Non melanoma skin cancer
    Oligospermia (reversible)
    Opportunistic infections
    Portal hypertension
    Secondary leukaemia
    Uterine carcinoma


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: August 2019

    Reference Sources

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 10th edition (2015) ed. Briggs, G., Freeman, R. and Yaffe, S. Lippincott Williams & Wilkins, Philadelphia.

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 3rd edition (2015) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Martindale: The Complete Drug Reference, 39th edition (2017) ed. Sweetman, S. Pharmaceutical Press, London.

    Summary of Product Characteristics: Hanixol 50mg tablets. Fontus Health Ltd. Revised June 2019.
    Summary of Product Characteristics: Mercaptopurine 50mg tablets. Aspen Europe. Revised December 2018.
    Summary of Product Characteristics: Xaluprine 20mg/ml oral suspension. Nova Laboratories Ltd. Revised May 2020.

    The Renal Drug Handbook. 4th edition. (2014) ed. Ashley, C and Currie, Radcliffe Publishing Ltd, Abingdon.

    N.A.P.O.S. The Drug Database for Acute Porphyria
    Available at:
    Last accessed: 22 August 2019

    NICE Evidence Services Available at: Last accessed: 20 August 2019

    Access the full UK drug database with a FREE Medscape UK Account
    It takes just a few minutes, and you’ll get unlimited access to information on over 11,000 UK drugs.
    Register for Free

    Already a member? Log in

    Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content

    FDB Logo

    FDB Disclaimer : FDB Multilex is intended for the use of healthcare professionals and is provided on the basis that the healthcare professionals will retain FULL and SOLE responsibility for deciding what treatment to prescribe or dispense for any particular patient or circumstance.