title: Switch from epoetin to darbepoetin alfa in hemodialysis: dose equivalence and hemoglobin stability.
abstract: OBJECTIVE
  The objective of the study reported here was to describe dose equivalence and hemoglobin (Hb) stability in a cohort of unselected hemodialysis patients who were switched simultaneously from epoetin alfa to darbepoetin alfa.
  
  
  METHODS
  This was a multicenter, observational, retrospective study in patients aged ≥18 years who switched from intravenous (IV) epoetin alfa to IV darbepoetin alfa in October 2007 (Month 0) and continued on hemodialysis for at least 24 months. The dose was adjusted to maintain Hb within 1.0 g/dL of baseline.
  
  
  RESULTS
  We included 125 patients (59.7% male, mean [standard deviation (SD)] age 70.4 [13.4] years). No significant changes were observed in Hb levels (mean [SD] 11.9 [1.3] g/dL, 12.0 [1.5], 12.0 [1.5], and 12.0 [1.7] at Months -12, 0, 12 and 24, respectively, P=0.409). After conversion, the erythropoiesis-stimulating agent (ESA) dose decreased significantly (P<0.0001), with an annual mean of 174.7 (88.7) international units (IU)/kg/week for epoetin versus 95.7 (43.4) (first year) and 91.4 (42.7) IU/kg/week (second year) for darbepoetin (65% and 64% reduction, respectively). The ESA resistance index decreased from 15.1 (8.5) IU/kg/week/g/dL with epoetin to 8.1 (3.9) (first year) and 7.9 (4.0) (second year) with darbepoetin (P<0.0001). The conversion rate was 354:1 in patients requiring high (>200 IU/kg/week) doses of epoetin and 291:1 in patients requiring low doses.
  
  
  CONCLUSIONS
  In patients on hemodialysis receiving ESAs, conversion from epoetin alfa to darbepoetin alfa was associated with an approximate and persistent reduction of 65% of the required dose. To maintain Hb stability, a conversion rate of 300:1 seems to be appropriate for most patients receiving low doses of epoetin alfa (≤200 IU/kg/week), while 350:1 would be better for patients receiving higher doses.
authors.affiliation: Hospital de Basurto, Bilbao, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Arrieta
authors.affiliation: Hospital de Basurto, Bilbao, Spain.
authors.forename: Iñigo
authors.initials: I
authors.lastname: Moina
authors.affiliation: Hospital de Donostia, Donostia-San Sebastián, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Molina
authors.affiliation: Hospital de Galdakao-Usansolo, Galdakao, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Gallardo
authors.affiliation: Hospital de Cruces, Baracaldo, Spain.
authors.forename: María Luisa
authors.initials: ML
authors.lastname: Muñiz
authors.affiliation: Hospital de Santiago, Vitoria-Gasteiz, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Robledo
authors.affiliation: Hospital de Santiago, Vitoria-Gasteiz, Spain.
authors.forename: Oscar
authors.initials: O
authors.lastname: García
authors.affiliation: Policlínica de Guipúzcoa, Donostia-San Sebastián, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Vidaur
authors.affiliation: Hospital de Galdakao-Usansolo, Galdakao, Spain.
authors.forename: Rosa Inés
authors.initials: RI
authors.lastname: Muñoz
authors.affiliation: Hemobesa Clinica Virgen Blanca, Bilbao, Spain.
authors.forename: Izaskun
authors.initials: I
authors.lastname: Iribar
authors.affiliation: Hemobesa Clinica Virgen Blanca, Bilbao, Spain.
authors.forename: Román
authors.initials: R
authors.lastname: Aguirre
authors.affiliation: Dialbilbo, Bilbao, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Maza
keywords: chronic kidney disease; darbepoetin alfa; dose equivalence; epoetin alfa; hemodialysis; hemoglobin