Mercaptopurine Tablets, 50mg
Purpose of Medication and Method of Action
Mercaptopurine is indicated for maintenance therapy of acute lymphatic (lymphocytic, lymphoblastic) leukemia as part of a combination regimen.
Side Effects
Hepatotoxicity can occur with any dose, but seems to occur with more frequency when doses of 2.5mg/kg/day are exceeded. It is importan= t to monitor liver function tests weekly at the beginning of therapy, then monthly thereafter. Immunosuppression can also occur. If patients experienc= e side effects such as fever, sore throat, jaundice, nausea, vomiting, signs of local infection, bleeding from any site, or symptoms of anemia, they should consult their physician. Alopecia may also occur. =20
Drug Interactions
When mercaptopurine and allopurinol are used together, the dose of mercaptopurine should be reduced to one-quarter to one-third of the usual dose to avoid severe toxicity. There is usually complete cross-resistance between mercaptopurine and thioguanine. Enhanced marrow suppression has been noted in some patients taking trimethoprim-sulfamethoxazole. Inhibition of the anticoagulant effect of warfarin has been noted.
Cautions and Contraindications
This is a Pregnancy Category D medication.
Warnings
The most consistent dose-related toxicity is bone marrow suppression. Life-threatening infections and bleeding have been observed as a consequence of mercaptopurine induced granulocytopenia and thrombycytopenia. Monitoring of patient CBC counts is important.
Patient Medication Information
These information sheets do not list all known side effects of the medications, only the most common side effects. For a complete list of side effects please contact your local pharmacy or the actual drug manufacturing company.