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25 X 40 mg
The exact dose and duration of administration will depend on the nature and dosage of other cytotoxic drugs given in conjunction with thioguanine.
Thioguanine is variably absorbed following oral administration and plasma levels may be reduced following emesis or intake of food.
Thioguanine can be used at various stages of treatment in short term cycles. However it is not recommended for use during maintenance therapy or similar long-term continuous treatments due to the high risk of liver toxicity.
Adults: The usual dosage of thioguanine is between 100 and 200 mg/m² body surface area, per day.
Paediatric population: Similar dosages to those used in adults, with appropriate correction for body surface area, have been used.
Use in the elderly: There are no specific dosage recommendations in elderly patients. Thioguanine has been used in various combination chemotherapy schedules in elderly patients with acute leukaemia at equivalent doses to those used in younger patients.
Dosage in renal or hepatic impairment: Consideration should be given to reducing the dosage in patients with impaired hepatic or renal function.
TPMT-deficient patients: Patients with inherited little or no thiopurine S-methyltransferase (TPMT) activity are at increased risk for severe tioguanine toxicity from conventional doses of tioguanine and generally require substantial dose reduction. The optimal starting dose for homozygous deficient patients has not been established.
Most patients with heterozygous TPMT deficiency can tolerate recommended tioguanine doses, but some may require dose reduction. Genotypic and phenotypic tests of TPMT are available.
Thioguanine is indicated for the treatment of acute nonlymphocytic leukemia.
Hypersensitivity to tioguanine or to any of the excipients.
In view of the seriousness of the indications there are no absolute contra-indications.
If you are pregnant or breastfeeding.
Potentially carcinogenic and mutagenic. Impaired hepatic and renal function. Increased incidence of abortion during the first trimester.
For this product there is a lack of modern clinical documentation which can be used as support for determining the frequency of undesirable effects. Thioguanine is usually one component of combination chemotherapy and consequently it is not possible to ascribe the side effects unequivocally to this drug alone.
Very common: Bone marrow failure, Venoocclusive liver disease: hyperbilirubinaemia, hepatomegaly, weight increased due to fluid retention
and ascites. Portal hypertension: splenomegaly, varices oesophageal and thrombocytopenia. Hepatic enzyme increased, blood alkaline phosphatase increased and gamma glutamyltransferase increased, jaundice, hepatoportalsclerosis, portal fibrosis, nodular regenerative hyperplasia, peliosis hepatitis.
Common: Stomatitis, gastrointestinal disorder, Venoocclusive liver disease in shortterm cyclical therapy. Hyperuricaemia, Hyperuricosuria and urate nephropathy.
See prescribing information for full details.
Vaccinations with live organism vaccines are not recommended in immunocompromised individuals.
During concomitant administration of other myelotoxic substances or radiation therapy, the risk of myelosuppression is increased.
As there is in vitro evidence that aminosalicylate derivatives (e.g. olsalazine, mesalazine or sulfasalazine) inhibit the TPMT enzyme, they should be administered with caution to patients receiving concurrent thioguanine therapy.
Pregnancy and Lactation
Pregnancy: The use of tioguanine should be avoided whenever possible during pregnancy, particularly during the first trimester. In any individual case the potential hazard to the foetus must be balanced against the expected benefit to the mother.
As with all cytotoxic chemotherapy, adequate contraceptive precautions should be advised when either partner is receiving thioguanine.
Breastfeeding: There are no reports documenting the presence of thioguanine or its metabolites in maternal milk. It is suggested that mothers receiving thioguanine should not breast feed.
Symptoms and Signs: The principal toxic effect is on the bone marrow and haematological toxicity is likely to be more profound with chronic overdosage than with a single ingestion of thioguanine.
Treatment: As there is no known antidote the blood picture should be closely monitored and general supportive measures, together with appropriate blood transfusion instituted if necessary.
Further management should be as clinically indicated or as recommended by the national poisons center, where available.