Hemactiv Mechanism of Action

Therapeutic Action: Anti-anemia hormonal agent. Hematopoietic agent. Erythropoiesis stimulant agent. ATC Code: B03XA01.
Pharmacology: Endogenous erythropoietin (EPO) is a glycoprotein produced in the kidney in response to hypoxia and stimulates the production of red blood cells in the bone marrow from erythroid progenitors, being the key regulator of red blood cells production. After EPO binds to the receptor on the cell surface, its active signals interfering with apoptosis and stimulates the proliferation of erythroid cells. Recombinant human erythropoietin (r-hu EPO) produced by recombinant DNA technology is identical in amino acid sequence and has the same biological effects of endogenous urinary erythropoietin.
Pharmacodynamics: After administration of erythropoietin alpha, increased reticulocytes within 10 days of starting treatment, followed by increased levels of red blood cells, hemoglobin and hematocrit within 2-6 weeks are observed. The rate of increase of hemoglobin is variable between patients and dose-dependent, but in patients on hemodialysis no higher response at doses greater than 300 IU/kg three times a week was observed.
Pharmacokinetics: After intravenous administration of erythropoietin alpha, the elimination half-life ranges from 4 to 6 h in healthy volunteers and from 6.5 to 9.3 h in patients with chronic renal failure. After subcutaneous administration, serum levels are lower than those for i.v. route, the levels increase slowly and reach a peak between 12 to 18 h post-dose which is much lower than that achieved for i.v. route (approx. 1/20 of the i.v. value). After subcutaneous administration, erythropoietin levels remain increased for about 72 h. When 3 weekly doses are used, no accumulation is observed, and levels remain stable, whether determined 24 hours after the first injection and 24 hours after the last injection. The subcutaneous bioavailability is 20-30% of the intravenous bioavailability.