The Molecular Basis of the Action of Chloroquine in Porphyria Cutanea Tarda

Porfiria cutânea tardia

“…122,127 Chloroquine is effective, however relapse occurs earlier than after phlebotomy. 117 There are several hypotheses to explain the mechanism of action of chloroquine: (1) it chelates iron from hepatocytes, which is later eliminated; 128 (2) it reduces ALA-synthetase activity; 129 (3) it forms a complex with uroporphyrin, which is excreted by the liver through the bile, 130 but the model utilized is not comparable to human PCT 129 , and (4) it increases the excretion of porphyrins by means of exocytosis and has a porphyrinostatic effect, inhibiting porphyrin formation. 124 Phlebotomy associated to chloroquine is employed when there is inadequate response the either treatment alone.…”

The porphyrias: a review.

“…Chloroquine forms a complex with porphyrins and an abnormally high intracellular concentration may account for its hepatotoxic action in these patients (Scholnick and Marver, 1968 (Taddeini and Watson, 1968). Liver function tests, particularly the bromsulphthalein retention time, show moderate, not usually severe, impairment of liver function (Waldenstrom and Haeger-Aronsen, 1960).…”

Cimetidine in the Treatment of Porphyria Cutanea Tarda.

“…A reduced hepatic activity of the enzyme uroporphyrinogen decarboxylase (UROD) is the biochemical defect responsible for the disease (1,2). Phlebotomy and chloroquine have been reported effective in the treatment of patients with PCT; these treatments need careful management due to side effects such as anemiaand hepatotoxicity, respectively (3,4).…”