Porphyria cutanea tarda induced by tamoxifen.

Porphyria cutanea tarda (PCT) results from a decrease in the activity of uroporphyrinogen decarboxylase. In the sporadic form, the decrease in the activity is restricted to the liver and is generally related to alcohol, estrogens, iron overload, hepatitis C infection, and halogenated aromatic hydrocarbons. We describe the development of porphyria cutanea tarda in a 53-year-old woman one year after breast cancer surgery and the initiation of treatment with tamoxifen. No additional drugs were prescribed. After tamoxifen was discontinued, a gradual clinical and laboratorial improvement was noticed suggesting a causative role of the drug. There are many reports discussing tamoxifen side-effects, but there are only three case reports in the literature that describe tamoxifen as a probable trigger of porphyria cutanea tarda. In this report, the potential porphyrinogenicity of tamoxifen and clinical implications are the targets of our discussion.