EPOETIN ALFA - A REVIEW OF ITS PHARMACODYNAMIC AND PHARMACOKINETIC PROPERTIES AND THERAPEUTIC USE IN NONRENAL APPLICATIONS

Epoetin alfa is a recombinant form of the principal hormone responsibl e for erythrogenesis, erythropoietin. Already an established treatment for anaeinia associated with renal failure, epoetin alfa may also be used to correct anaemia in other patient groups. The drug increases th e capacity for autologous blood donation in patients scheduled to unde rgo surgery and attenuates the decrease in haematocrit often seen in u ntreated autologous donors. However transfusion requirements did not s ignificantly decrease in many trials. Epoetin alfa also accelerates re d blood cell recovery after allogeneic - but not autologous - bone mar row transplant. Limited data in patients with adult rheumatoid arthrit is suggest that while epoetin alfa increases haematocrit/haemoglobin l evels, overall clinical rheumatological status may not improve. Howeve r, the drug did improve quality of life in a small cohort of children with juvenile rheumatoid arthritis in addition to correcting anaemia. Response rates to treatment with epoetin alfa in patients with anaemia associated with cancer range between 32 and 85%. Anaemia associated w ith cancer chemotherapy also responds well to treatment with the drug as does anaemia associated with zidovudine therapy in patients with ac quired immune deficiency syndrome (AIDS). Studies evaluating the use o f epoetin alfa as treatment for anaemia of prematurity have used diffe rent methodologies and dosages, making overall analysis difficult. Nev ertheless, it appears that high dosages are necessary for response. Re sults from 1 study suggest that treatment with epoetin alfa appears to be more costly than transfusional support in this application; the re levance of this finding is questionable, however given that the aim of treatment with epoetin alfa is elimination of transfusion requirement s. The incidence of many adverse elements associated with epoetin alfa treatment in patients with renal failure (hypertension, seizures and thromboembolic events) has been minimal in patients without renal fail ure. Adverse events occurred at a similar rate in placebo and epoetin alfa recipients in placebo-controlled trials evaluating the use of rit e drug as treatment for anaemia in patients with cancer receiving chem otherapy or patients with AIDS receiving zidovudine. In summary, epoet in alfa is an effective alternative to blood transfusion, reducing ana emia and producing consequent improvements in quality of life in many nonrenal applications. It was more effective than placebo in a number of double-blind trials and may be particularly useful as treatment for anaemia associated with other drugs such as cisplatin and zidovudine.