Imiquimod: Wirkmechanismen und Therapieindikationen

Several immune modulators are used in the treatment and side-effect management in dermatology and particular dermato-oncology. Among these cytokines the interferons and especially interferon-a are most important. Interferons comprise a pleiotropic mode of action with antiproliferative, antiviral and immunomodulating effects. Interferons which are predominantly administered via the subcutaneous or intravenous route have therefore a broad spectrum of indications. Imiquimod belongs to a relatively new group of immune response modifiers (IRM), which can be used as a topical treatment in various dermatological diseases. Imiquimod stimulates the induction, synthesis and release of interferon-a, interleukin 1, 6 and 12 as well as TNF-α from monocytes and dendritic cells. The induction of cytokines is mediated via,,toll-like receptors. The effects lead to a cell-mediated specific immune response (Th 1-response) modulation. According to the action spectrum of Imiquimod it is principally useful in several viral diseases as well as malignant conditions. Imiquimod (Aldara 5 % Creme) has been approved by most authorities for the treatment of external genital warts, Condylomata acuminata. In more than half of the treated patients complete responses of genital warts have been notified. The major focus of the therapeutic action spectrum of Imiquimod is seriously the treatment of tumor precursors, semi-malignant and malignant skin tumors. Several studies have been published on the efficacy in superficial and nodular basalcell carcinomas (BCCs), actinic keratoses and Morbus Bowen with complete remission rates between 80 and 90%. This article will provide an overview on the action mechanism and potential indications for Imiquimod in dermatology.