Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Blood clotting: This medication can reduce the number of platelet cells in the blood. Platelets help the blood to clot, and a shortage could make you bleed more easily. Tell your doctor of any signs that your blood is not clotting as quickly as usual. Such symptoms may include black and tarry stools, blood in the urine, easy bruising, or cuts that won't stop bleeding.
Gout: This medication increases the blood levels of uric acid, which may increase the risk of gout.
Infection: As well as killing cancer cells, this medication can reduce the number of cells that fight infection in the body (white blood cells). Avoid contact with people with contagious infections and tell your doctor if you begin to notice signs of an infection, such as fever or chills.
Pregnancy: There is a possibility of birth defect if either the man or woman is using thioguanine at the time of conception. As well, it may harm the baby if used during pregnancy. Effective birth control should be practiced while using this medication.
This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: It is not known whether thioguanine passes into breast milk. Because of the risks associated with this medication, a decision should be made to stop breast-feeding or to stop the medication, taking into account the importance of the medication to the mother.