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In general, patients with lower baseline serum erythropoietin levels responded more vigorously to EPOGEN (r) than patients with higher baseline erythropoietin levels. Although no specific serum erythropoietin level can be stipulated above which patients would be unlikely to respond to EPOGEN (r) therapy, treatment of patients with grossly elevated serum erythropoietin levels (eg, > 200 mUnits/ mL) is not recommended. Pharmacokinetics Intravenously administered EPOGEN (r) is eliminated at a rate consistent with first order kinetics with a circulating half-life ranging from approximately 4 to 13 hours in adult and pediatric patients with CRF. 14-16 Within the therapeutic dose range, detectable levels of plasma erythropoietin are maintained for at least 24 hours. After SC administration of EPOGEN (r) to patients with CRF, peak serum levels are achieved within 5 to 24 hours after administration and decline slowly thereafter. There is no apparent difference in half-life between adult patients not on dialysis whose serum creatinine levels were greater than 3, and adult patients maintained on dialysis. Text Continues Below
In normal volunteers, the half-life of IV administered EPOGEN (r) is approximately 20% shorter than the half-life in CRF patients. The pharmacokinetics of EPOGEN (r) have not been studied in HIV-infected patients. The pharmacokinetic profile of EPOGEN (r) in children and adolescents appears to be similar to that of adults. Limited data are available in neonates. It has been demonstrated in normal volunteers that the 10,000 Units/ mL citrate-buffered Epoetin alfa formulation and the 40,000 Units/ mL phosphate-buffered Epoetin alfa formulation are bioequivalent after SC administration of single 750 Units/ kg doses. The Cmax and t1/ 2 after administration of the phosphate buffered Epoetin alfa formulation were 1.8 ± 0.7 Units/ mL and 19.0 ± 5.9 hours (mean ± SD), respectively. The corresponding mean ± SD values for the citrate-buffered Epoetin alfa formulation were 2 ± 0.9 Units/ mL and 16.3 ± 3. 0 hours. There was no notable accumulation in serum after two weekly 750 Units/ kg SC doses of Epoetin alfa. Page: << Prev | 1 | 2 | 3
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