Effective treatment of actinic keratosis with 0.5% fluorouracil cream for 1, 2, or 4 weeks.

New therapeutic options would benefit patients with actinic keratosis (AK), a precancerous condition that is a significant health concern. The efficacy and safety of a microsphere-based formulation of 0.5% fluorouracil cream were evaluated in a randomized, double-blind, multicenter, parallel-group study. Patients (N= 177) were randomized to receive 0.5% fluorouracil or vehicle once daily for 1, 2, or 4 weeks. Efficacy was assessed by lesion counts and clearance. Safety was evaluated by monitoring adverse events, including facial irritation. Significant improvements were seen from baseline to posttreatment follow-up in all efficacy variables for all fluorouracil regimens compared with vehicle. Patients treated for one week experienced significant improvements compared with vehicle, although efficacy increased with increasing treatment duration. Most patients experienced mild to moderate facial irritation of predictable onset and duration. Once-daily administration of 0.5% fluorouracil cream for 1, 2, or 4 weeks is safe and effective for the treatment of AKs.