"The U.S. Food and Drug Administration today approved Zydelig (idelalisib) to treat patients with three types of blood cancers.
Zydelig is being granted traditional approval to treat patients whose chronic lymphocytic leukemia (CLL) has retu"...
- Acute Nonlymphocytic Leukemias: TABLOID brand Thioguanine is indicated
for remission induction and remission consolidation treatment of acute nonlymphocytic
leukemias. However, it is not recommended for use during maintenance therapy
or similar long term continuous treatments due to the high risk of liver toxicity
(see WARNINGS and ADVERSE
The response to this agent depends upon the age of the patient (younger patients faring better than older) and whether thioguanine is used in previously treated or previously untreated patients. Reliance upon thioguanine alone is seldom justified for initial remission induction of acute nonlymphocytic leukemias because combination chemotherapy including thioguanine results in more frequent remission induction and longer duration of remission than thioguanine alone.
- Other Neoplasms: TABLOID brand Thioguanine is not effective in chronic lymphocytic leukemia, Hodgkin's lymphoma, multiple myeloma, or solid tumors. Although thioguanine is one of several agents with activity in the treatment of the chronic phase of chronic myelogenous leukemia, more objective responses are observed with MYLERAN® (busulfan), and therefore busulfan is usually regarded as the preferred drug.
DOSAGE AND ADMINISTRATION
TABLOID brand Thioguanine is administered orally. The dosage which will be tolerated and effective varies according to the stage and type of neoplastic process being treated. Because the usual therapies for adult and pediatric acute nonlymphocytic leukemias involve the use of thioguanine with other agents in combination, physicians responsible for administering these therapies should be experienced in the use of cancer chemotherapy and in the chosen protocol.
There are individuals with an inherited deficiency of the enzyme thiopurine methyltransferase (TPMT) who may be unusually sensitive to the myelosuppressive effects of thioguanine and prone to developing rapid bone marrow suppression following the initiation of treatment. Substantial dosage reductions may be required to avoid the development of life-threatening bone marrow suppression in these patients (see WARNINGS). Prescribers should be aware that some laboratories offer testing for TPMT deficiency.
Ninety-six (59%) of 163 pediatric patients with previously untreated acute nonlymphocytic leukemia obtained complete remission with a multiple-drug protocol including thioguanine, prednisone, cytarabine, cyclophosphamide, and vincristine. Remission was maintained with daily thioguanine, 4-day pulses of cytarabine and cyclophosphamide, and a single dose of vincristine every 28 days. The median duration of remission was 11.5 months.8
Fifty-three percent of previously untreated adults with acute nonlymphocytic leukemias attained remission following use of the combination of thioguanine and cytarabine according to a protocol developed at The Memorial Sloan-Kettering Cancer Center. A median duration of remission of 8.8 months was achieved with the multiple-drug maintenance regimen which included thioguanine.
On those occasions when single-agent chemotherapy with thioguanine may be appropriate, the usual initial dosage for pediatric patients and adults is approximately 2 mg/kg of body weight per day. If, after 4 weeks on this dosage, there is no clinical improvement and no leukocyte or platelet depression, the dosage may be cautiously increased to 3 mg/kg/day. The total daily dose may be given at one time.
The dosage of thioguanine used does not depend on whether or not the patient is receiving ZYLOPRIM (allopurinol); this is in contradistinction to the dosage reduction which is mandatory when PURINETHOL (mercaptopurine) or IMURAN (azathioprine) is given simultaneously with allopurinol.
Procedures for proper handling and disposal of anticancer drugs should be considered. Several guidelines on this subject have been published.1-8
There is no general agreement that all of the procedures recommended in the guidelines are necessary or appropriate.
Greenish-yellow, scored tablets containing 40 mg thioguanine, imprinted with "WELLCOME" and "U3B" on each tablet; in bottles of 25 (NDC 0173-0880-25).
Store at 15° to 25°C (59° to 77°F) in a dry place.
1. ONS Clinical Practice Committee. Cancer Chemotherapy Guidelines and Recommendations for Practice. Pittsburgh, PA: Oncology Nursing Society; 1999:32-41.
2. 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 and Human Services, 1992, US Dept of Health and Human Services, Public Health Service publication NIH 92-2621.
3. AMA Council on Scientific Affairs. Guidelines for handling parenteral antineoplastics. JAMA. 1985;253:1590-1591.
4. 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.
5. Clinical Oncological Society of Australia. Guidelines and recommendations for safe handling of antineoplastic agents. Med J Australia. 1983;1:426-428.
6. Jones RB, Frank R, Mass T. Safe handling of chemotherapeutic agents: a report from the Mount Sinai Medical Center. CA-A Cancer J for Clin. 1983;33:258-263.
7. American Society of Hospital Pharmacists. ASHP technical assistance bulletin on handling cytotoxic and hazardous drugs. Am J Hosp Pharm. 1990;47:1033-1049.
8. Controlling Occupational Exposure to Hazardous Drugs. (OSHA Work-Practice Guidelines.) Am J Health-Syst Pharm. 1996;53:1669-1685.
Manufactured by: DSM Pharmaceuticals, Inc. Greenville, NC 27834 for GlaxoSmithKline, Research Triangle Park, NC 27709. December 2004. FDA Rev date: 11/15/2004
Last reviewed on RxList: 7/25/2008
This monograph has been modified to include the generic and brand name in many instances.
Additional Tabloid Information
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