Epoetin alfa and beta are natural hormone-like substances found in the body that stimulate the bone marrow to produce red blood cells. They are mass-produced using recombinant genetic engineering techniques and used as an injectable treatment for anaemia.

Epoetin alfa and beta are also known as erythropoietin. The alfa and beta forms have exactly the same effects. In the United Kingdom epoetin alfa is marketed by Janssen-Cilag under the trade name Eprex and by Roche under the tradename NeoRecormon. In the United States, it is also known by the trade names Epogen and Procrit.

In people with HIV, epoetin alfa is used to alleviate the anaemia caused by AZT (zidovudine, Retrovir). It can also alleviate the anaemia resulting from hepatitis C treatment in HIV-co-infected patients^[1]. No significant side-effects have been seen in people with HIV.

A recent study showed that epoetin alfa can be dosed once weekly at 40,000U in patients with anaemia, and results in increases in haemoglobin (the key constituent of red blood cells) and improved quality of life^[2][3]. Another study has found that it may be dosed every two or three weeks once a person has achieved a haemoglobin level above 13g/dl^[4]. The standard alternative treatment for anaemia is blood transfusion, but one study has found that this was associated with increased risk of death in HIV patients with anaemia, even after adjusting for antiretroviral use, AIDS status, CD4 cell count, viral load and haemoglobin level. In contrast, epoetin alfa was not linked to an increased risk of death^[5].

Another synthetic form of erythropoietin, called recombinant human erythropoietin or r-HuEPO, has been successfully used to treat pregnant HIV-infected women^[6]. A test-tube study has also shown that epoetin alfa and beta may prevent neuropathy caused by HIV or nucleoside reverse transcriptase inhibitors (NRTIs)^[7].

A related synthetic form of erythropoietin called darbepoetin alfa (Aranesp) can also be used to treat anaemia in HIV-positive patients. Although administered at a lower dose than epoetin alfa, the two drugs had similar efficacy and side-effects in a study of HIV-positive patients undergoing haemodialysis because of chronic kidney disease. However, darbepoetin alfa may be preferable as it is injected once a week and may be more cost-effective than epoetin alfa^[8].