Doses - MERCAPTOPURINE

Dogs:

For treatment of immune-mediated diseases or acute lymphocytic and granulocytic leukemias:
a) 50 mg/m2 PO once daily (q24h) to effect, then every other day (q48h) or as needed.(Jacobs, Lumsden et al. 1992)
Monitoring Parameters - 1) Hemograms (including platelets) should be monitored closely; initially every 1-2 weeks and every 1-2 months once on maintenance therapy. It is recommended bysome clinicians that if the WBC count drops to between 5, 000-7, 000 cells/mm3 the dose be reducedby 25%. If WBC count drops below 5, 000 cells/mm3 treatment should be discontinued untilleukopenia resolves; 2)Liver function tests; serum amylase, if indicated; 3) Efficacy
Client Information - Clients must be briefed on the possibilities of severe toxicity developingfrom this drug, including drug-related neoplasms or mortality. Clients should contact veterinarianshould the animal exhibit symptoms of abnormal bleeding, bruising, anorexia, vomiting or infection.
Although, no special precautions are necessary with handling intact tablets, it is recommended towash hands after administering the drug.
Dosage Forms/Preparations/FDA Approval Status/Withholding Times - Veterinary-Approved Products: None

Human-Approved Products:

Mercaptopurine Oral Tablets 50 mg; Purinethol® (Glaxo Wellcome); (Rx)