A comparative study of the results of phlebotomy therapy and low-dose chloroquine treatment in porphyria cutanea tarda.

Longer remissions after the phlebotomy therapy than after the low-dose chloroquine treatment were ascertained by means of the long-term follow-up of a large group of porphyria cutanea tarda patients. An attempt to prove the dependence of the length of laboratory and clinical remission on the values of initial porphyrinuria, on the degree of morphological liver changes, and on the total amount of blood withdrawn at phlebotomy was unsuccessful. On the contrary, a direct relationship was observed between the length of remission and the age of the subject on commencing treatment. At the same time, it was impossible to prove a causal relationship between the length of remission and initial porphyrinuria, the degree of morphological liver changes, and the total dose of drug taken, in the group of patients on the low-dose chloroquine therapy.