Efudex is a topical fluorinated cream used for the treatment of actinic keratosis. It belongs to the class of antimetabolite agents that target proliferative skin cells. After topical application the active metabolite 5-fluorouracil is generated in epidermal cells. The metabolite interferes with dna synthesis by inhibiting thymidylate synthase, leading to depletion of thymidine pools. This results in impaired replication of rapidly dividing keratinocytes, causing cellular death and clearance of abnormal lesions. Pharmacologically the drug is absorbed minimally into systemic circulation, providing a localized therapeutic effect with minimal systemic exposure. The overall pharmacodynamic action relies on selective metabolic activation within diseased skin, producing cytotoxic effects limited to targeted cells.

Efudex is a topical medication used to treat superficial skin lesions. Its active ingredient is fluorouracil, a synthetic analogue of the nucleic acid base uracil. Fluorouracil is converted inside skin cells into active metabolites that inhibit thymidylate synthase. Inhibition of this enzyme blocks the formation of thymidine needed for dna synthesis. The resulting deficiency in dna production prevents the proliferation of abnormal cells. This mechanism leads to the selective destruction of damaged or cancerous skin tissue while sparing healthy cells.

Efudex is a topical medication that contains fluorouracil and is applied to the skin. Fluorouracil works by interfering with dna synthesis in rapidly dividing cells. Common side effects include redness irritation and dryness at the application site. These reactions are usually mild and may increase with continued use. Some individuals may experience burning sensations swelling or crusted skin. The risk of scarring or changes in skin colour is possible but not typical. Long term use can lead to persistent pigment alterations in some cases.

Efudex commonly causes localized skin irritation including redness and itching. Patients may also experience a burning or stinging sensation during treatment. The treated area can become dry, flaky, or develop superficial ulcers. Swelling, tenderness, or mild pain may occur as part of the inflammatory response. These effects typically appear within the first few weeks and may persist for several weeks after discontinuation. Systemic side effects are uncommon but can include headache or fever in rare cases.