Acute and chronic arsenic poisoning associated with treatment of acute promyelocytic leukaemia

Seven relapsed and/or refractory acute promyelocptic leukaemia patients wer e treated by arsenic trioxide (As2O3). Four patients (4/7, 57%) achieved co mplete remission after one to three cycles of treatment and the most common acute side-effect was fluid retention tin six patients, 86%), including we ight gains and pleuro-pericardial effusions. Evident polyneuropathy compati ble with chronic arsenic toxicity was noted in two of the three patients wh o received As2O3 maintenance therapy and one of them had marked distal musc ular atrophy. We suggest that As2O3 may be a useful salvage therapy for rel apsed and refractory APL patients, but the acute or chronic arsenic toxicit y should be carefully monitored.