Mercaptopurine

Cytostatic · Antimetabolite

Indications

Remission induction, maintenance therapy in acute lymphoblastic leukaemia and acute myelogenous leukaemia.

Dosage

Adults & Children: Induction: Initial: 2.5 mg/kg/day. Calculate to nearest multiple of 25 mg. Titrate: May increase to 5 mg/kg/day after 4 wk if needed. Maintenance: 1.5-2.5 mg/kg/day. Dose paeds in pm.

Adverse Effects

Myelosuppression, liver toxicity, anorexia, nausea, oral ulceration, biliary stasis, hepatotoxicity, GI upset, anorexia.

Risk Factor (Pregnancy/Lactation)

Pregnancy: Contraindicated in pregnancy. Lactation: Contraindicated or not recommended. Contraindications: Severe liver disease, severe bone marrow suppression. Precautions: Renal or hepatic impairment. Monitor liver function and bloods. Impaired thiopurine methyltransferase activity. During remission induction, monitor uric acid levels in blood and urine. Hodgkin's disease, myasthenia gravis. Risk of lymphoproliferative disorders and other malignancies. Autoimmune conditions; risk of macrophage activation syndrome (discontinue if occurs). Elderly.

Interactions

Allopurinol, warfarin, olsalazine, mesalazine, sulphasalazine, febuxostat, aminosalicylates, live vaccines, dairy products.

Advice to Patient

Take atleast 1 hour before or 2 hours after meals. Take at the same time each day. For mouth sores or headache, consult prescriber for appropriate medications. Contact prescriber if there is constant fever, chills, sore throat, nausea, vomiting, burning on urination, fatigue, easy bruising or bleeding, dark coloured stools, unrelieved mouth sores, difficulty in breathing, swelling of extremities, change in urinary pattern, unusual weight gain. Take sufficient amount of fluids (2-3 litres per day) to maintain hydration, unless restricted by the prescriber. Avoid highly crowded places to prevent infection. Do not get vaccinated without consulting prescriber.

Pharmacokinetics

Absorption: Variable and incomplete (approx. 50% of a dose is absorbed); Cmax of suspension is 34% higher than the tablet. Metabolism: Hepatic and GI mucosa. Half-life elimination: Tablet: Children: 21 minutes; Adults: 47 minutes; Suspension: Approx. 2 hours. Time to peak, serum: Within 2 hours. Excretion: Urine.

Brands with this active ingredient

• Mercaprine
• Purinetone

Compiled by Healify Pharmacy from published drug references. How we compile it →

Always consult a pharmacist or doctor.