Imiquimod in clinical practice.

Applied topically, imiquimod induces the production of interferon-alpha plus other cytokines. Because intralesional interferon is effective in the treatment of condylomata acuminata (genital warts), topical imiquimod has also been investigated as a potential therapy for this condition. The dosing regimen found to best balance efficacy, side-effects and practicality is 5% imiquimod cream applied overnight by the patient three times weekly until warts clear, for up to 16 weeks. The largest double-blind trial to examine this protocol involved 311 patients with external anogenital warts who were randomized to use imiquimod 5% cream, imiquimod 1% cream or vehicle cream. Evaluation of all patients given medication at any time showed that 50% of those who received 5% imiquimod experienced clearing of all baseline warts, as compared to 21% of those who used 1% imiquimod and 11% of those treated with vehicle. Overall, 5% imiquimod treatment was significantly more effective than vehicle (P < 0.0001). Excluding patients who discontinued medication for reasons unrelated to therapy (such as moving out of town or poor compliance), 56% of those who received 5% imiquimod experienced complete clearing of baseline warts. Clearing also occurred in 27% of those who received imiquimod 1%. Recurrence of baseline warts occurred in 13% of patients whose warts cleared with 5% imiquimod. When applied overnight at home three times each week, topical imiquimod 5% cream is an effective therapy with acceptable side-effects. The recurrence rate is low and further studies to specifically compare recurrence rates are warranted.