"Scientists at the National Institutes of Health report they have discovered in mouse studies that a small molecule released in the spinal cord triggers a process that is later experienced in the brain as the sensation of itch.
There exists the potential for a delayed hypersensitivity reaction to fluorouracil. Patch testing to prove hypersensitivity may be inconclusive1.
The patient should avoid prolonged exposure to sunlight or other forms of ultraviolet irradiation during treatment with FLUOROPLEX® (fluorouracil topical cream) Cream, as the intensity of the reaction may be increased.
There is a possibility of increased absorption through ulcerated or inflamed skin.
Carcinogenesis, mutagenesis, impairment of fertility
Adequate long-term studies in animals to evaluate carcinogenic potential have not been conducted with fluorouracil. In three in-vitro cell transformation assays, fluorouracil produced morphological transformation of cells. Morphological transformation was also produced in one of these in-vitro assays by a metabolite of fluorouracil and the transformed cells produced malignant tumors when injected into immunosuppressed syngeneic mice. Fluorouracil has been shown to exert mutagenic acitivity in the yeast cells, Bacillus subtilis and Drosophila assays. In addition, fluorouracil has produced chromosome damage at concentrations of 1.0 and 2.0 mcg/mL in an in vitro hamster fibroblast assay and increases in micronuclei formation in the bone marrow of mice at intraperitoneal doses within the human therapeutic dose range of 12-15 mg/kg/day. Patients receiving cumulative doses of 0.24-1.0 g of fluorouracil parenterally have shown an increase in numerical and structural chromosome aberrations in peripheral blood lymphocytes. Fluorouracil has been shown to impair fertility after parenteral administration in rats. In mice, single-dose intravenous and intraperitoneal injections of fluorouracil have been reported to kill differentiated spermatogonia and spermatocytes at a dose of 500 mg/kg and produce abnormalities in spermatids at 50 mg/kg.
Teratogenic effects: Pregnancy Category X: Fluorouracil may cause fetal harm when administered to a pregnant woman. Fluorouracil administered parenterally has been shown to be teratogenic in mice, rats and hamsters, and embryolethal in monkeys. Fluorouracil is contraindicated in women who are or may become pregnant. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus.
It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, and because there is some systemic absorption of fluorouracil after topical administration (see PRECAUTIONS: General), mothers should not nurse their infants while receiving this drug.
Safety and effectiveness in pediatric patients have not been established.
1. Epstein E. Testing for 5-fluorouracil allergy: patch and intradermal tests. Contact Dermatitis 1984; 10:311.
Last reviewed on RxList: 5/6/2009
This monograph has been modified to include the generic and brand name in many instances.
Additional Fluoroplex Information
Fluoroplex - User Reviews
Fluoroplex User Reviews
Now you can gain knowledge and insight about a drug treatment with Patient Discussions.
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Find out what women really need.