Efudex: Should it be prescribed by dentists?
This question was submitted by a general dentist: When discussing sun damage to lips, a couple of patients indicated that their physician prescribed Efudex. There is apparently no follow-up by the physician and no indication to the patients as to what the desired outcome of the said treatment should be. Should dentists be prescribing this medication and what would the appropriate follow-up and regimen be with this chemotherapeutic agent?
Dr. Mark Donaldson provided the following initial and quick response
Dr. Mark Donaldson is Director of Pharmaceutical Services at the Kalispell Regional Medical Center, Clinical Professor in the Department of Pharmacy at the University of Montana, and Clinical Associate Professor in the School of Dentistry at the Oregon Health and Sciences University
Efudex (topical fluorouracil) is a pyrimidine antimetabolite that interferes with DNA synthesis by blocking the methylation of deoxyuridylic acid; fluorouracil inhibits thymidylate synthetase (TS), or is incorporated into RNA. The reduced folate cofactor is required for tight binding to occur between the 5-FdUMP and TS. Historically this has been an intravenous formulation to treat breast cancer, colorectal cancer, gastric cancer and pancreatic cancer, with the new topical formulation showing promise in treating actinic or solar keratoses (sun-damaged lips) and superficial basal cell carcinomas.
While the usual dosing regimen for sun-damaged lips is to apply to lesions twice daily for 2-4 weeks (although complete healing may not be evident for 1-2 months following treatment), this is a hazardous drug and should not be routinely prescribed by dentists without a complete understanding of the risks of this medication and all of the appropriate patient counseling.
Patients should apply the cream 10 minutes after washing, rinsing, and drying the affected area. Apply using fingertip (wash hands immediately after application) or nonmetal applicator. Do not cover area with an occlusive dressing. Avoid exposure to ultraviolet rays during and immediately following therapy. Wash hands immediately after topical application of the 5% cream. Topical preparations are for external use only; not for ophthalmic, oral, or intravaginal use. Teratogenic effects have been observed with parenteral administration in animal studies; fetal defects and miscarriages have been reported following use of topical products in humans. Use is contraindicated during pregnancy. Systemic toxicity normally associated with parenteral administration (including neutropenia, neurotoxicity, and gastrointestinal toxicity) has been associated with topical use particularly in patients with a genetic deficiency of dihydropyrimidine dehydrogenase (DPD). Patients may experience eye irritation, alopecia, or skin irritation and should report immediately to the prescriber any signs of infection, dyspnea, or severe asthenia. Educate patient about signs of a significant reaction (e.g., wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Fluorouracil is a hazardous agent that requires appropriate precautions for handling and disposal (http://www.cdc.gov/niosh/docs/2012-150/pdfs/2012-150.pdf).
Given these guidelines, I am not certain that any general dentist would want to begin prescribing this drug, and certainly not without close patient follow up. The last consideration may be cost as the average wholesale price (US AWP) for a 40g tube of the 5% cream is $303.92 (10/08/2013). I hope this information is of value to you.
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