Deferiprone-associated myelotoxicity.

Agranulocytosis developed in a 63-year-old patient with myelodysplasia 6 weeks after commencing treatment with the oral iron chelator deferiprone (L1, 1,2-dimethyl-3-hydroxypyrid-4-one, CP20) at a daily dose of 79 mg/kg. This was the 3rd case of agranulocytosis (neutrophils 0 x 10(9)/l) in clinical trials of L1 at the Royal Free Hospital. The neutrophil count recovered 7 days after stopping L1 and commencing G-CSF at a dose of 300 micrograms daily. Three other patients with milder degrees of neutropenia (neutrophils < 1.5 x 10(9)/l) have also been observed in our trials. The case histories of these 4 patients are described here; other reported cases of neutropenia or agranulocytosis are reviewed. Based on worldwide long-term clinical trials the incidence of agranulocytosis is about 1.6% and of neutropenia 2%.