[Current issues in erythropoietin therapy of renal anemia]

Recombinant human erythropoietin has been used for more than 20 years for the treatment of renal anaemia, with epoetin-alfa and -beta representing the common traditional preparations. By the modification of the molecule's carbohydrate moiety or structure a longer duration of erythropoietin receptor stimulation was achieved. The administration of these new molecules (darbepoetin, C.E.R.A.) once or twice a month is also sufficient to achieve serum haemoglobin target levels, making the treatment safer and more comfortable both for the patients and the personnel. These recently developed synthetic erythropoietin receptor stimulating molecules, along with recombinant human erythropoietin, are together called "Erythropoiesis Stimulating Agents". In haemodialysed patients the intravenous route is preferred, but the subcutaneous administration can substantially reduce dose requirements. In praedialysed, transplanted or peritoneally dialysed patients, erythropoiesis stimulating agents should preferably be given subcutaneously both for economic and practical reasons. There are ongoing clinical trials with erythropoiesis stimulating molecules that can be administered by inhalation or per os. Current evidence suggests that the serum haemoglobin level should preferably not exceed 12 g/dl with the use of erythropoiesis stimulating agents. No cardiovascular protective effect of higher serum haemoglobin levels was demonstrated in two large clinical trials. Further well-designed studies are necessary to set evidence-based haemoglobin targets for erythropoiesis stimulating treatment. Arguments for a more widespread use of agents with extended duration include medical, financial and patient satisfaction reasons. The release of new erythropoiesis stimulating agents may further simplify the treatment of renal anaemia.