RESULTS OF LONG-TERM DEFERIPRONE (L1) THERAPY - A REPORT BY THE INTERNATIONAL STUDY-GROUP ON ORAL IRON CHELATORS

This report updates the combined experience of four centres involved i n the long-term treatment of transfusional iron overload in 84 patient s with the oral iron chelator deferiprone (L1) over 167 patient-years. The source of L1 was variable, including two university research labo ratories and three pharmaceutical firms. Compliance was rated as excel lent in 48%, intermediate in 36%, and poor in 16% of patients. On a me an L1 dose of 73-81 mg/kg/d, urinary iron excretion was stable, at aro und 0.5 mg/kg/d, with no indication of a diminishing response with tim e. Serum ferritin showed a very steady decrease with time from an init ial mean +/- 1 SD of 4207 +/- 3118 to 1779 +/- 1154 mu g/l after 48 mo nths (P < 0.001). 17 patients abandoned L1 therapy. Major complication s of L1 requiring permanent discontinuation of treatment included agra nulocytosis (three), severe nausea (four), arthritis (two) and persist ent liver dysfunction (one), The remaining patients abandoned treatmen t because of low compliance (three) and conditions unrelated to L1 tox icity (four). Lesser complications permitting continued L1 treatment i ncluded transient mild neutropenia (four), zinc deficiency (12), trans ient increase in liver enzymes (37), moderate nausea (three) and arthr opathy (17). There was no treatment-related mortality. Although the co mplications associated with L1 treatment are significant and require c lose monitoring, they do not preclude effective long-term therapy in t he vast majority of patients, Further well-controlled prospective stud ies of L1 are required in order to enable proper judgement of its suit ability for general long-term clinical use.