The use of darbepoetin in infants with chronic renal impairment.

Darbepoetin is a newer analogue of epoetin, with a longer half-life, that allows less frequent administration. There are currently no published data available for its use in infants. We report our experience with this drug in infants with chronic renal impairment, weighing less than 8 kg. Infants had baseline haemoglobin (Hb), iron, ferritin and transferrin levels measured. They were started on approximately 0.5 microg/kg per week of darbepoetin. Hb levels were checked every 2-4 weeks, and iron studies were performed every 4 weeks. Iron supplementation was prescribed to maintain ferritin levels>100 microg/l and transferrin saturation levels>20%. Follow up was for 20 weeks. Six infants with a mean weight of 4.08 kg and a mean creatinine of 259 micromol/l were included. Three infants were medically stable throughout the study, and the mean darbepoetin dose was decreased to 0.25 microg/kg per week. Their dosing interval was increased to every 3-4 weeks. The other three infants were less stable and had multiple medical problems, including periods of haemodialysis and surgery. These infants failed to reach target Hb level, despite an increase in the mean dose of darbepoetin to 1.2 microg/kg per week. In conclusion, darbepoetin can be successfully administered to infants with chronic renal insufficiency, but the dose needs to be tailored to each individual. Administration would be facilitated by smaller unidose syringes.