Chloroquine in treatment of porphyria cutanea tarda. Long-term efficacy of combined phlebotomy and high-dose chloroquine therapy.

The combined treatment with phlebotomy and high-dose chloroquine for PCT is described and 21 patients treated were followed up for periods of up to 6 years. Clinical and laboratory remissions were experienced by all patients. The urinary excretion of porphyrin and serum hepatic enzyme levels rose rapidly during therapy and then fell, mostly to levels well below that before treatment. The periods required for normalization of laboratory tests, median value, were 1.5 months for liver enzymes and 7 months for uroporphyrins. Clinical symptoms soon disappeared, blistering within 3 weeks and skin fragility within 12. Mild nausea or subfebrility was noted in some cases, but no other serious acute or chronic adverse reactions were observed. Clinical or biochemical relapse appeared in 9/21 (43%) patients who were then retreated. Relapsing cases showed a symptomfree period of 1-2.5 years after each treatment. Liver biopsy was performed in 4 relapsing cases prior to the repeated treatment and showed only mild siderosis and a mild fatty infiltration consistent with pathological liver findings in PCT but no evidence of chloroquine-induced permanent liver damage. The longest symptomfree period observed up to date was assessed for 7 patients who were followed up for more than 2 years after 1 single treatment. Four (57%) of them were symptomfree 5-6 years and no clinical or biochemical signs of relapse were observed. Our data confirm the efficacy of the high-dose therapeutic procedure, and the combined regimen with 1-2 phlebotomies prior to the chloroquine administration seems to be a safe procedure without any serious side effects. Our findings are discussed in relation to other current therapeutic modalities.