Fluorouracil Disease Interactions

5- FU can cause severe and fatal myelosuppression. Therapy with 5- FU should be administered cautiously in patients who have had prior high-dose pelvic irradiation or alkylating agents or who have widespread metastatic tumor involvement of the bone marrow. Patients should be instructed to immediately report any signs or symptoms suggesting bone marrow suppression such as fever, sore throat, local infection, or bleeding. Close clinical monitoring of hematopoietic function is recommended and therapy should be withheld if platelet counts falls below 100,000/mm3 and/or white blood cell (WBC) counts falls below 3500/mm3 or a rapid fall in WBC is noted.

Fluorouracil (5-FU) should not be used in patients with potentially serious infectious diseases. 5-FU induces myelosuppression. All patients should be instructed to immediately report any signs or symptoms suggesting infection such as fever, sore throat, or local infection during therapy with 5-FU. Close clinical monitoring of hematopoietic function is recommended.

Fluorouracil (5-FU) induces stomatitis in the gastrointestinal tract. Therapy with 5-FU should be administered with extreme caution in patients with peptic ulcer disease and ulcerative colitis.

Fluorouracil (5- FU) induces myelosuppression, including thrombocytopenia. Therapy with 5- FU should be administered cautiously in patients with bleeding tendencies. Therapy with 5- FU should be promptly discontinued following bleeding from any sight. Patients should be instructed to immediately report any signs or symptoms suggesting bleeding such as petechiae, purpura, hematuria, or melena. Close clinical monitoring of hematopoietic function is recommended. Therapy with 5- FU should be withheld if platelet counts falls below 100,000/mm3.

Fluorouracil can cause cardiotoxicity, including angina, myocardial infarction, arrhythmia and heart failure based on post marketing reports. Reported risk factors for cardiotoxicity include administration by continuous infusion rather than intravenous bolus and presence of coronary artery disease. Caution and monitoring is advised in patients with coronary artery disease. Treatment should be discontinued for cardiotoxicity. The risks of treatment resumption after cardiotoxicity has been resolved have not been established.

Capecitabine is metabolized to fluorouracil. Capecitabine and fluorouracil are not recommended for use in patients known to have certain variants in the DPYD gene known to result in complete (or near complete) DPD deficiency; enzymatic deficiency results in increased systemic drug exposure. Consider testing for genetic variants of DPYD prior to initiating therapy. No dose of capecitabine or fluorouracil has been proven safe for patients with complete DPD deficiency and there are insufficient data to recommend a dose in patients with partial DPD deficiency. Withhold or permanently discontinue therapy (based on clinical judgement) in patients with evidence of acute early-onset or unusually severe adverse reactions, which may indicate complete DPD deficiency.