Topical therapy with 5‐fluorouracil

Abstract

Actinic keratoses are unsightly and may be precancerous. Solitary or localized lesions respond adequately to many forms of treatment. However, widespread multiple actinic keratoses can best be treated with topical 5‐fluorouracil. The exact mode of action is not known, but we can presume it is related to the clearly established effect of this drug upon RNA and DNA synthesis. This treatment is almost ideal, since it usually destroys the keratoses selectively, without significant alteration in normal skin. A 1 or 2 percent solution is made by diluting the 10 ml ampule with propylene glycol. This liquid is applied two times daily to the involved areas for a 2–4 week period. Lesions on the face and neck respond more quickly than those of the hands and arms. A brisk, painful, inflammatory reaction at the site of the keratoses is anticipated and used as an indicator of the end point of treatment. Once treatment is discontinued, the erythema usually subsides in 2 weeks and the skin becomes smooth and free of keratoses. Not all keratoses respond, and untoward reactions such as phototoxicity, irritation of the mucous membranes, contact sensitivity, and alteration of pigmentation can occur. Although resolution of the keratoses persists for years, should they return reapplication is usually effective again.

Actinic Keratoses Treated with a Combination of Topical 5-Fluorouracil and Dinitrochlorobenzene

“…Treatment periods between 8 and 9 weeks have been recommended for lesions on the upper limbs [Jansen, 1977], In our study we found it necessary to treat patients for 6-8 weeks with or without the combination of DNCB.…”

“…Various drugs have been used in combination with topical 5FU. These include sodium hydroxide, 2-5% [Jansen, 1977], retinoic acid [Robinson and Kligman, 1975], and sali cylic acid [Goncalres, 1975],…”

“…Since the introduction of 5-fluorouracil (5FU) as a topical chemo therapeutic medication for the treatment of neoplasms of the skin, there have been numerous reports on its mechanism of action, effectiveness and side effects [Jansen, 1977], Its use on the face has been well established and accepted, but it has been shown to be relatively ineffective when used on the forearms and dorsa of the hands. This study was undertaken to determine the effectiveness of the combined use of 5FU and dinitrochlorobenzene (DNCB) on actinic keratoses of the upper limbs.…”

Evaluation of the Effectiveness of Imiquimod and 5-Fluorouracil for the Treatment of Actinic Keratosis: Critical Review and Meta-analysis of Efficacy Studies

“…[5][6][7][8] Topical 5-fluorouracil (5-FU) is a wellknown nonsurgical treatment for AK and is available in 0.5%, 1% and 5% formulations. [9][10][11][12][13][14][15] As a schemotherapeutic agent, fluorouracil essentially destroys AK by interfering with DNA and RNA synthesis by blocking the methylation reaction of deoxyuridylic acid to thymidylic acid. This causes thymine deficiency, particularly in cells mat are growing quickly and taking up fluorouracil at a more rapid rate, leading to unbalanced growth and death of these cells.…”

Chemexfoliation and Superficial Skin Resurfacing

“…The ability of AHAs to eradicate AKs is variable and depends on peel depth [29]. 5-FU is an antimetabolite that inhibits DNA and RNA synthesis and destroys hyperproliferative AKs [30]. A major limitation in the use of daily 5-FU topical regimen is severe erythema, local irritation, and discomfort associated with the treatment period of 4-8 weeks [31].…”