Low-dose oral chloroquine in the treatment of porphyria cutanea tarda.

Seven patients with porphyria cutanea tarda received a total of ten courses of low-dose oral chloroquine therapy (125 mg chloroquine phosphate twice weekly). Patients were treated for a mean 14.9 months during which time all went into clinical and biochemical remission. Relapse occurred in four patients on a total of six occasions after a mean 17 months. In four patients there was no relapse after a mean 47.3 months. There were no adverse side-effects from the treatment. Low-dose oral chloroquine therapy appears to be a safe, effective and convenient treatment for porphyria cutanea tarda, although relapses may occur requiring further therapy.