Fluorouracil cream

Fluorouracil is used in several combination regimens in the treatment of breast cancer. It also has palliative activity in gastrointestinal adenocarcinomas, including those originating in the stomach, pancreas, liver, colon, and rectum. Other tumors in which some antitumor effects have been reported include carcinomas of the ovary, cervix, oropharynx, bladder, and prostate. Topical 5-fluorouracil cream has been useful in the treatment of premalignant keratoses of the skin and superficial basal cell carcinomas, but it should not be used in invasive skin cancer. 

Cumulative amount permeated was 19.1- and 7-fold more than fluorouracil aqueous solution and fluorouracil cream, respectively. 

If Efudex Cream contains 5% of fluorouracil, calculate the percentage (w/w) of fluorouracil in the prescription. 

Fluorouracil present in Efudex Cream can be found by the method of proportion ... 

Fluorouracil/ Topical [5-FU] (Efudex) [Antineoplastic/ Antimetabollte] Uses Basal cell carcinoma actinic/solar k atosis Action Inhibits thymidylate S5mthetase (-1- DNA S5mth, S-phase specific) Dose 5% cream bid X 2-6 wk Caution [D, ] Irritant chemo Contra Component sensitivity Disp Cream, soln SE Rash, dry skin, photosens EMS See RuorouracU OD See RuorouracU... 

Interferes w/ DNA synth Dose Adults. Anaerobic Infxns 500 mg IV q6-8h Amebic dysentery 750 mg/d PO for 5-10 d Trichomoniasis 250 mg PO tid for 7 d or 2 g PO X 1 C. difficile 500 mg PO or IV qSh for 7-10 d (PO preferred IV only if pt NPO) Vaginosis 1 applicator-full intravag bid or 500 mg PO bid for 7 d Acne rosacea/skin Apply bid Peds. 30 mg/ kg PO/IV/d q6H, 4 g/d max-s-. Amebic dysentery 35-50 mg/kg/24 h PO in 3 -s- doses for 5-10 d Rx 7-10 d for C. difficile-, in hepatic impair Caution [B, M] Avoid EtOH Contra 1st tri of PRO Disp Tabs, caps, IV, topical lotion, intravag gel, cream SE Disulfiram-like Rxn dizziness, HA, GI upset, anorexia, urine discoloration Interactions t Effects W/ cimetidine T effects OF carbamazepine, fluorouracil, Li, warfarin -1- effects W/ barbiturates, cholestyramine, colestipol, phenytoin EMS t Effects of anticoagulants concurrent EtOH use can cause disulfiram-like Rxn (tach, N/V, sweating, flushing, headache, blurred vision, confusion) may cause a metallic taste and discolored urine OD May cause N/V/D, numbness in hands and feet, Szs, and loss of coordination symptomatic and supportive... 

Fluorouracil is normally given intravenously (Table 55-3) and has a short metabolic half-life on the order of 15 minutes. It is not administered by the oral route because its bioavailability is erratic due to the high levels of the breakdown enzyme dihydropyrimidine dehydrogenase present in the gut mucosa. Floxuridine (5-fluoro-2 -deoxyuridine, FUDR) has an action similar to that of fluorouracil, and it is only used for hepatic artery infusions. A cream incorporating fluorouracil is used topically for treating basal cell cancers of the skin. 

Many clinicians prescribe pyridoxine tablets or cream to manage this side-effect, however the evidence for this treatment is scarce. Severe manifestations may have to be managed by delay and/or dose modification of the patient s next cycle of chemotherapy (only the 5-fluorouracil component need be dose modified). 

A 64-year-old man was treated with Efudix ointment (containing 5% fluorouracil) for actinic keratosis (115). Patch-testing with the constituents of the cream showed a doubtful reaction to fluorouracil 5% in petroleum jelly however, intradermal injection of fluorouracil 10 mg/ml gave a positive reaction. 

Fluorouracil (5-FU) is a cytotoxic agent used to treat solid tumours, such as those of the breast and colon. However, its prodrug capecitabine (Xeloda) is much better absorbed orally. 5-FU, applied as a cream, is also very useful for the treatment of certain skin cancers. It is significant that 8% of the population lack an enzyme that can metabolise 5-FU. In these people, administration of normal doses of the drug can lead to dangerously high toxic levels in the blood. 

The 5% cream contains fluorouracil in a vanishing-cream base consisting of white petrolatum, stearyl alcohol, propylene glycol, polysorbate 60, and parabens (methyl and propyl). 

Two patients taking iow-dose methotrexate had a toxic skin reaction when they started to use a cream containing fluorouracil. The activity of systemic treatment with methotrexate and fluorouracii are said to be dependent on the order in which the two drugs are given, but this does not appear to be important in the commoniy used CMF regimen. 

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