In adult and pediatric patients with CKD, the elimination half-life (t1/2) of plasma erythropoietin after intravenous administration of PROCRIT ranged from 4 to 13 hours. After subcutaneous administration, Cmax was achieved within 5 to 24 hours. The t1/2 in adult patients with serum creatinine greater than 3 mg/dL was similar between those not on dialysis and those maintained on dialysis. The pharmacokinetic data indicate no apparent difference in PROCRIT t1/2 among adult patients above or below 65 years of age.