Efficacy and safety assessment of 0.5% and 1% colchicine cream in the treatment of actinic keratoses

BACKGROUND: Topical colchicine has been reported to be an effective treatment for actinic keratoses, but the optimal concentration has not been fully defined. OBJECTIVE: The aim of this study was to further support the beneficial effect of topical colchicine therapy for actinic keratoses, and to compare the efficacy and safety of two different concentrations of colchicine cream, 0.5% and 1%. METHODS: Sixteen patients with actinic keratoses were enrolled in this comparative randomized study. Eight patients applied 1% colchicine cream, twice daily on their lesions while the other eight were treated with a 0.5% colchicine cream for 10 days. Some patients were applied a second course of 10 days' therapy. Patients were examined before treatment and at 10 days, and followed up at 1, 2 and 6 months of treatment. Visible and palpable actinic keratoses lesions in each group were counted. Safety and efficacy were also assessed by clinical examination at each study visit. Routine laboratory tests were performed before and after treatment. RESULTS: Actinic keratoses lesions showed significant clinical improvement following treatment with 0.5% and 1% colchicine cream. Complete healing of actinic keratoses were observed in six of the eight patients in the 1% colchicine group, and in seven of the eight patients in the 0.5% colchicine group. The reduction rate in number of actinic keratoses at the end of treatment in the 1% colchicine group was 73.9% (48/65) ( p < 0.001), and the reduction rate in the 0.5% colchicine group was 77.7% (52/67) in total ( p < 0.001). The reduction in number of actinic keratoses (mean - SD) at the end of treatment was similar in the 1% colchicine group (0.7 - 1.3), and the 0.5% colchicine group (mean 0.6 - 1.7) ( p > 0.05). Systemic side effects were not seen in either concentration. CONCLUSIONS: Topical colchicine is an effective and safe alternative agent. Cream containing 0.5% of colchicine is equally effective as 1% colchicine cream in the treatment of actinic keratoses.