New drugs for dermatologic diseases.

Since its isolation less than 20 years ago, cyclosporine has become one of the major drugs in the armamentarium of transplant surgeons. A serendipitous event in 1979 suggested the drug might offer significant benefits in patients with psoriasis. Multiple trials have subsequently confirmed its usefulness in psoriasis at steadily decreasing dosages. Administered orally, the drug must be taken in a ritualistic fashion as it tends to sequestrate on the sides of the glass. A routine determination of blood levels becomes important in order to maintain the peak and trough concentrations within a relatively narrow window of safety. Depending on the particular assay used, significant differences in concentrations appear, making knowledge of the laboratory's normal values essential. Blood levels of cyclosporine vary with multiple drugs, including erythromycin, prednisone, and ketoconazole. The drug acts principally via its interference with the function of the helper T lymphocytes. Clofazimine (Lamprene) offers another weapon, especially for therapy of resistant pustulosis of the palms and soles.