ERYTHROPOIETIN

'Erythropoietin' (IPA pronunciation: , alternative pronunciations: ) or 'EPO' is a glycoprotein hormone that is a cytokine for erythrocyte (red blood cell) precursors in the bone marrow. Also called hematopoietin or hemopoietin, it is produced by the kidney, and is the hormone regulating red blood cell production.

Contents

Uses

Anemia due to renal failure

Critically ill patients

Blood doping

Adverse effects

Safety advisories in anemic cancer patients

See also

Additional images

References

External links

Uses

Erythropoietin is available as a therapeutic agent produced by recombinant DNA technology in mammalian cell culture. It is used in treating anemia resulting from chronic renal failure or from cancer chemotherapy.

Anemia due to renal failure

In patients who have chronic renal failure, iron should be given with erythropoietin.^[1]

Critically ill patients

In a randomized controlled trial, erythropoietin reduced insignificantly reduced mortality among critically ill patients. If larger studies find a statistically significant result and the same event rates, 35 patients would need treatment to prevent one death (number needed to treat is 35)^[2] Although the editorial accompanying the trial concluded this benefit was insufficient, less patients would require this treatment to save one life than the number of patients treated with other commonly accepted interventions (such as primary prevention of coronary disease in patients with hypertriglyceridemia. If the benefit must be weighed against the 5% absolute increase in thrombosis.

Blood doping

It has a history of usage as a blood doping agent in endurance sports such as bicycle racing, triathlons and marathon running.

Adverse effects

Erythropoietin is associated with an increased risk of adverse cardiovascular complications in patients with kidney disease if it is used to increase hemoglobin levels above 13.0 g/dl.^[3]

Safety advisories in anemic cancer patients

Amgen sent a "dear doctor" letter in January, 2007, that highlighted results from a recent anemia of cancer trial, and warned doctors to consider use in that off-label indication with caution.
Amgen advised the United States FDA as to the results of the DAHANCA 10 clinical trial. The DAHANCA 10 data monitoring committee found that 3-year loco-regional control in subjects treated with Aranesp was significantly worse than for those not receiving Aranesp (p=0.01).
In response to these advisories, the FDA released a Public Health Advisory^[4]
on March 9, 2007, and a clinical alert^[5] for doctors on February 16, 2007, about the use of erythropoeisis-stimulating agents such as epogen and darbepoetin. The advisory recommended caution in using these agents in cancer patients receiving chemotherapy or off chemotherapy, and indicated a lack of clinical evidence to support improvements in quality of life or transfusion requirements in these settings.
In addition, on March 9, 2007, drug manufacturers agreed to new black box warnings about the safety of these drugs.
On March 22, 2007, a congressional inquiry into the safety of erythropoeitic growth factors was reported in the news media. Manufacturers were asked to suspend drug rebate programs for physicians and to also suspend marketing the drugs to patients.

See also

★ Amgen, producer of artificial EPO (Brand Names: Epogen and Aranesp)

★ Dynepo, trademark name for an erythropoiesis stimulating protein, by TKT

★ Blood doping, transfusions and EPO use as doping methods; testing and enforcement

★ Jehovah's Witnesses and blood transfusions

Additional images

References

1. A randomized controlled study of iron supplementation in patients treated with erythropoietin, Macdougall IC, Tucker B, Thompson J, Tomson CR, Baker LR, Raine AE, , , Kidney Int., 1996
2. Howard L. Corwin et al., “Efficacy and Safety of Epoetin Alfa in Critically Ill Patients,” N Engl J Med 357, no. 10 (September 6, 2007): 965-976, http://content.nejm.org/cgi/content/abstract/357/10/965 (accessed September 6, 2007).
3. Normalization of hemoglobin level in patients with chronic kidney disease and anemia, Drüeke TB, Locatelli F, Clyne N, Eckardt KU, Macdougall IC, Tsakiris D, Burger HU, Scherhag A, , , N. Engl. J. Med., 2006
4. FDA Public Health Advisory: Erythropoiesis-Stimulating Agents (ESAs): Epoetin alfa (marketed as Procrit, Epogen), Darbepoetin alfa (marketed as Aranesp)
5. Information for Healthcare Professionals: Erythropoiesis Stimulating Agents (ESA)

External links

★ Patient information on Epogen

★ Patient information on Aranesp

★ Patient information on Procrit

★ EPO F.A.Q.