Monograph Details

Neoplasms > Antimetabolites
PURINETHOL
Manufacturer
Gate Pharmaceuticals
Legal Classification
Rx
Pharmacological Class
Antimetabolite.
Generic Name
Mercaptopurine (6-MP) 50mg; scored tabs.
Indications
Maintenance therapy of acute lymphatic leukemia as part of a combination regimen.
Adults and Children
1.5–2.5mg/kg per day as a single dose. Concomitant allopurinol: reduce dose of mercaptopurine to ⅓–¼ of the usual dose. TPMT-deficient, renal or hepatic impairment: reduce dose, see literature.
Contraindications
Prior resistance to mercaptopurine.
Precautions
Not effective in CNS leukemia, acute myelogenous leukemia, chronic lymphocytic leukemia, the lymphomas (including Hodgkin's disease), or solid tumors. Renal impairment. Monitor liver function tests weekly at start of therapy, then monthly thereafter; discontinue if hepatotoxicity occurs. Pre-existing liver disease (monitor more frequently). Obtain CBCs with differential, hemoglobin, hematocrit, platelets; discontinue if severe bone marrow suppression occurs. Thiopurine-S-methyltransferase (TPMT) deficient: increased risk of myelosuppression, consider genotypic/phenotypic testing. Pregnancy (Cat. D); esp. 1st trimester, nursing mothers: not recommended.
Interactions
Increased risk of bone marrow suppression with allopurinol, aminosalicylate derivatives (eg, olsalazine, mesalazine, sulphasalazine), trimethoprim-sulfamethoxazole. Antagonizes warfarin. Caution with concomitant hepatotoxic agents.
Adverse Reactions
Myelosuppression, hyperuricemia/hyperuricosuria, GI upset, intestinal ulceration, rash, hyperpigmentation, alopecia, oligospermia; hepatotoxicity, infection, immunosuppression.
How Supplied
Tabs—60
Additional Resources
Related Prescribing Note