Diclofenac (ATC code: D11A X18) for topical administration is safety classified as Probably not porphyrinogenic because of minimal systemic exposure and because diclofenac for systemic use (ATC code: M01A B05) is classified as Probably not porphyrinogenic (PNP). For more details of the metabolism of diclofenac please refer to the monograph of diclofenac for systemic use (ATC code: M01A B05).

Absorption after topical administration is < 1-12% (SPC).

Uneventful use reported in 4 patients with acute porphyria.