5-Methoxypsoralen (Bergapten) in photochemotherapy of psoriasis.

5-Methoxypsoralen (5-MOP, Bergapten) was evaluated as a potential photosensitizing drug in oral photochemotherapy of psoriasis. Treatment results indicate that (1) 5-MOP is as effective as, and in high doses more effective than, 8-methoxypsoralen in clearing psoriatic lesions; (2) therapeutic doses of 5-MOP do not lead to erythema; the acute side-effects of 8-MOP PUVA therapy--erythema, blistering, pruritus--are thus avoided; (3) even high doses of 5-MOP are not followed by nausea. 5-MOP PUVA therapy thus represents a real alternative to 8-MOP PUVA, its advantages over 8-MOP PUVA being greater safety and patient acceptance.