Topical treatment of psoriasis with the topoisomerase inhibitors novobiocin and nalidixic acid: a pilot study.

Our studies in human epidermal keratinocytes as a model system have suggested that the antibiotic topoisomerase II inhibitors, novobiocin and nalidixic acid, may be of value for the treatment of hyperproliferative skin disorders. We have therefore conducted a pilot study of the clinical efficacy of these compounds for the treatment of psoriasis. The compounds were administered topically to psoriatic plaques in seven healthy patients over a period of 6 weeks. Nalidixic acid (2%) or novobiocin (2% or 5%) in methylcellulose were applied twice daily under occlusion, and methylcellulose alone was used as a control. In six of the seven patients, one or both compounds effected somewhat greater improvement than in the control within 3 weeks of treatment.