ABSTRACT
The immunosuppressive macrolides are a novel class of antiinflammatory substances, which could supplant glucocorticosteroids for the topical treatment of some chronic inflammatory skin diseases. Cyclosporine A (CyA), well known from transplantation medicine for years, is licensed in Germany for oral treatment of psoriasis and atopic dermatitis but is not suitable for topical therapy. Tacrolimus (FK506) penetrates the inflamed epidermis and is regarded as the key immunosuppressive macrolide. Clinical trials have demonstrated the efficacy of FK506 ointment for atopic dermatitis, many case reports have been published regarding other inflammatory skin diseases. The ascomycin derivative ASM 981 has many of the properties of FK506 but less data is available at present. Sirolimus (Rapamycin) is structurally related to FK506 but has other biological effects since its molecular actions involve different biochemical pathways. A review of the biochemical and cellular properties, mode of action, therapeutic efficacy and unwanted side effects, as well as data from clinical trials and status of licensing, is given for the respective drugs.