uced to one third to one quarter of the usual dose to avoid severe toxicity.
Dosage in TPMT-deficient Patients
Patients with inherited little or no thiopurine S-methyltransferase (TPMT) activity are at increased risk for severe Purinethol toxicity from conventional doses of mercaptopurine and generally require substantial dose reduction. The optimal starting dose for homozygous deficient patients has not been established. (See CLINICAL PHARMACOLOGY, WARNINGS, and PRECAUTIONS sections.)
Most patients with heterozygous TPMT deficiency tolerated recommended Purinethol doses, but some require dose reduction. Genotypic and phenotypic testing of TPMT status are available. (See CLINICAL PHARMACOLOGY, WARNINGS, and PRECAUTIONS sections.)
Dosage in Renal and Hepatic Impairment
It is probably advisable to start with lower dosages in patients with impaired renal function, due to slower elimination of the drug and metabolites and a greater cumulative effect. Consideration should be given to reducing the dosage in patients with impaired hepatic function.
How is Purinethol Supplied
Pale yellow to buff, scored tablets containing 50 mg mercaptopurine, imprinted with “Purinethol” and “04A”; bottles of 60 (NDC 57844-522-06).
Store at 15° to 25°C (59° to 77°F) in a dry place.
REFERENCES
ONS Clinical Practice Committee. Cancer Chemotherapy Guidelines and Recommendations for Practice. Pittsburgh, PA: Oncology Nursing Society;1999:32-41.
Recommendations for the safe handling of parenteral antineoplastic drugs. Washington, DC: Division of Safety; Clinical Center Pharmacy Department and Cancer Nursing Services, National Institutes of Health; 1992. US Dept of Health and Human Services. Public Health Service publication NIH 92-2621.
AMA Council on Scientific Affairs. Guidelines for handling parenteral antineoplastics. JAMA. 1985;253:1590-1591.
National Study Commission on Cytotoxic Exposure. Recommendations for handling cytotoxic agents. 1987. Available from Louis P. Jeffrey, Chairman, National Study Commission on Cytotoxic Exposure. Massachusetts College of Pharmacy and Allied Health Sciences, 179 Longwood Avenue, Boston, MA 02115.
Clinical Oncological Society of Australia. Guidelines and recommendations for safe handling of antineoplastic agents. Med J Australia. 1983;1:426-428.
Jones RB, Frank R, Mass T. Safe handling of chemotherapeutic agents: a report from the Mount Sinai Medical Center. CA-A Cancer J for Clinicians. 1983;33:258-263.
American Society of Hospital Pharmacists. ASHP technical assistance bulletin on handling cytotoxic and hazardous drugs. Am J Hosp Pharm. 1990;47:1033-1049.
Controlling Occupational Exposure to Hazardous Drugs. (OSHA Work-Practice Guidelines.) Am J Health-Syst Pharm. 1996;53:1669-1685.
Manufactured for:
Teva Biologics and Specialty Products
Division of Teva Pharmaceuticals USA
Horsham, PA 19044
Manufactured by:
DSM Pharmaceuticals, Inc.
Greenville, NC 27834
Rev. G 6/2011
PRINCIPAL DISPLAY PANEL
Purinethol Tablets 50 mg 60s Label Text
NDC 57844-522-06
Purinethol®
(mercaptopurine)
Each scored tablet contains:
50 mg
Rx only
60 Tablets
TEVA
