Clinical use, therapeutic aspects and future potential of deferiprone in thalassemia and other conditions of iron and other metal toxicity.

The therapeutic aspects and future prospects of the new iron chelating drug deferiprone are reviewed, with an emphasis on its clinical use in thalassemia and other conditions of iron overload, imbalance and toxicity, as well as its possible use in other metal toxicity conditions. Orally administered deferiprone appears to be as effective as subcutaneous deferoxamine in the removal of iron in transfused iron loaded patients, with an equivalent therapeutic index profile in both animals and humans. Only about 10% of patients requiring iron chelation therapy worldwide receive deferoxamine mainly because of its high cost, toxicity and low compliance with subcutaneous administration. Deferiprone has been used by over 6000 patients in 40 countries worldwide, in some cases daily for more than 10 years, with very promising results. Doses of 50-120 mg/kg/day are effective in bringing patients to negative iron balance. Deferiprone increases urinary iron excretion, decreases serum ferritin levels and reduces liver iron in the majority of chronically transfused iron loaded patients. All of the toxic side effects of deferiprone are considered reversible and manageable, and include agranulocytosis, musculoskeletal and joint pains, gastrointestinal complaints and zinc deficiency. In general, the incidence of toxic side effects could be reduced by using lower doses or combination therapy with deferoxamine. The suggestion that deferiprone therapy may cause liver fibrosis has not been confirmed. New therapeutic protocols for maximizing the efficacy and minimizing the toxicity of deferiprone are being considered based on new findings in relation to its metal chelation, pharmacological, toxicological and metabolic properties. (c) 2001 Prous Science. All rights reserved.