[8-methoxypsoralen serum content of problem patients in PUVA therapy].

Abstract

Beside the stage, expression and course of psoriasis as well as the compliance of patients low or abnormal 8-MOP levels are the cause of the ineffectiveness of the PUVA-therapy, as we could demonstrate in 7 of 11 problem cases. Thus, we determined only a maximal 8-MOP concentration of 47 ng/ml serum as an extreme value in one patient and on other patient had his maximal serum peak 3-4 hours after 8-MOP-application and only a value of 8-MOP of 18 ng/ml serum at the recommended time of irradiation. In this connection a first pass mechanism for 8-MOP by a limited biotransformation capacity in the liver is significant and one basic reason for the interindividual variation. Therefore in these cases the knowledge of the individual serum profiles of 8-MOP is helpful to adapt the time of irradiation to the individual necessities and/or to increase the 8-MOP doses.