PLASMA-LEVELS OF PROTOPORPHYRIN-IX IN HUMANS AFTER ORAL-ADMINISTRATION OF 5-AMINOLEVULINIC ACID

We report on the pharmacokinetics of PP formation and elimination in 4 patients after the administration of oral ALA (60 mg kg(-1)). After a brief distribution phase, plasma PP levels decline (half life = 8 h) and was almost undetectabIe by 48 h post-administration. This confirms pharmacokinetic clinical data which show that ALA results in a shorte ned interval of skin photosensitization compared with other sensitizer s such as Photofrin and 'HPD'. A brief summary of other clinical-toxic ity findings is reported.