Cimetidine in the treatment of porphyria cutanea tarda.

The efficacy of the H2 receptor antagonist, cimetidine, in the treatment of a patient with porphyria cutanea tarda (PCT) was evaluated. After administration of cimetidine for 2 weeks, urinary excretion of uroporphyrin (UP) and coproporphyrin (CP) was significantly decreased. Urinary porphyrin levels remained low even after the cessation of cimetidine for 1 week. Although the readministration of cimetidine did not decrease porphyrin excretion, skin lesions were markedly improved, and serum gamma-glutamyl transpeptidase (GGT), aminotransferases and serum ferritin decreased to the normal range. These results suggest that, in addition to efficacy in the treatment of acute intermittent porphyria (AIP) and erythropoietic protoporphyria (EPP), cimetidine is effective in the treatment of PCT.