Thioguanine Side Effects

Brand Names: Tabloid

Please note - some side effects for Thioguanine may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Side Effects of Thioguanine - for the Consumer

Thioguanine

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Thioguanine:

Loss of appetite; nausea; vomiting.

Severe allergic reactions (rash; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); cough or sore throat; dark urine; fever or chills; infection; joint pain; pale stools; severe or prolonged nausea or vomiting; stomach pain or bloating; sudden weight gain; swelling of the mouth; unusual bruising or bleeding; unusual paleness; unusual tiredness; yellowing of the skin or eyes.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.

Thioguanine Side Effects - for the Professional

Thioguanine

 The most frequent adverse reaction to Thioguanine is myelosuppression. The induction of complete remission of acute myelogenous leukemia usually requires combination chemotherapy in dosages which produce marrow hypoplasia. Since consolidation and maintenance of remission are also effected by multiple-drug regimens whose component agents cause myelosuppression, pancytopenia is observed in nearly all patients. Dosages and schedules must be adjusted to prevent life-threatening cytopenias whenever these adverse reactions are observed.

Hyperuricemia frequently occurs in patients receiving Thioguanine as a consequence of rapid cell lysis accompanying the antineoplastic effect. Adverse effects can be minimized by increased hydration, urine alkalinization, and the prophylactic administration of a xanthine oxidase inhibitor such as ZYLOPRIM® (allopurinol). Unlike PURINETHOL (mercaptopurine) and IMURAN® (azathioprine), Thioguanine may be continued in the usual dosage when allopurinol is used conjointly to inhibit uric acid formation.

Less frequent adverse reactions include nausea, vomiting, anorexia, and stomatitis. Intestinal necrosis and perforation have been reported in patients who received multiple-drug chemotherapy including Thioguanine.

Hepatic Effects

Liver toxicity associated with vascular endothelial damage has been reported when Thioguanine is used in maintenance or similar long-term continuous therapy which is not recommended. This usually presents as the clinical syndrome of hepatic veno-occlusive disease (hyperbilirubinemia, tender hepatomegaly, weight gain due to fluid retention, and ascites) or signs and symptoms of portal hypertension (splenomegaly, thrombocytopenia, and esophageal varices). Elevation of liver transaminases, alkaline phosphatase, and gamma glutamyl transferase and jaundice may also occur. Histopathological features associated with this toxicity include hepatoportal sclerosis, nodular regenerative hyperplasia, peliosis hepatitis, and periportal fibrosis.

Liver toxicity during short-term cyclical therapy presents as veno-occlusive disease. Reversal of signs and symptoms of this liver toxicity has been reported upon withdrawal of short-term or long-term continuous therapy.

Centrilobular hepatic necrosis has been reported in a few cases; however, the reports are confounded by the use of high doses of Thioguanine, other chemotherapeutic agents, and oral contraceptives and chronic alcohol abuse.

Side Effects by Body System - for Healthcare Professionals

Hematologic

Because thioguanine may have delayed effect, the drug should be withdrawn temporarily at the first sign of an abnormally large fall in any of the formed elements of the blood.

Hyperuricemia can be minimized by increased hydration, urine alkalinization, and the prophylactic administration of a xanthine oxidase inhibitor such as allopurinol.

Hematologic side effects including myelosuppression have been reported. Myelosuppression is the most frequent adverse reaction to thioguanine and may appear as anemia, leukopenia, and/or thrombocytopenia. The induction of complete remission of acute myelogenous leukemia usually requires combination chemotherapy in dosages which produce marrow hypoplasia. Since consolidation and maintenance of remission are also affected by multiple drug regimens whose component agents cause myelosuppression, pancytopenia is observed in nearly all patients.

Hyperuricemia frequently occurs in patients receiving thioguanine as a consequence of rapid cell lysis accompanying the antineoplastic effect.

Life-threatening infection and bleeding have been observed as consequences of thioguanine-induced granulocytopenia and thrombocytopenia.

Gastrointestinal

Gastrointestinal side effects including nausea, vomiting, diarrhea, anorexia, and stomatitis have been reported. Intestinal necrosis and perforation have been reported in patients who received multiple drug chemotherapy which included thioguanine.

If severe diarrhea and/or stomatitis develop, a decrease in dosage may be appropriate.

Hepatic

Hepatic side effects including veno-occlusive liver disease have been reported. A case of peliosis hepatitis has been reported. Liver enzyme and other liver function studies are occasionally abnormal.

If jaundice, hepatomegaly, or anorexia with tenderness in the right hypochondrium occurs, thioguanine should be withheld until the exact etiology can be determined.

Respiratory

Respiratory side effects including esophageal varices have been reported in patients receiving continuous busulfan and thioguanine therapy. Nasal congestion and rhinorrhea have been reported with high dose IV therapy.

Renal

Renal side effects including nephrotoxicity have been reported in high-dose therapy.

Dermatologic

Dermatologic side effects including the development of painful erythematous swelling of the palms and soles occurring several days after courses of therapy, have been reported in 5 women on cytarabine, doxorubicin, and thioguanine. Alopecia has also been reported.

Other

Other side effects including malaise, lethargy, weakness, ataxia, and loss of vibratory sensation have been reported.

Cardiovascular

Cardiovascular side effects have been reported. In one study, two of thirteen patients administered 700 mg/m2 intravenously developed bradycardia and nonspecific T-wave flattening, which resolved within 3 hours. In another study, five of nineteen patients administered 1000 mg/m2 intravenously demonstrated minor changes: bradycardia (two patients), nonspecific ST- and T-wave changes (five), and P-wave changes (one).

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date, and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This information does not endorse drugs, diagnose patients, or recommend therapy. This drug information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug of drug combination is safe, effective, or appropriate for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of information provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse, or pharmacist.