Comparison of darbepoetin alfa and epoetin alfa in the management of anemia of critical illness

Efficacy of IntraCoronary Erythropoietin Delivery BEfore Reperfusion-Gauging Infarct Size in Patients with Acute ST-segment Elevation Myocardial Infarction (ICEBERG)

Previous clinical studies have shown inconsistent results regarding the effect of erythropoietin in ST-segment elevation myocardial infarction (STEMI). This study investigated whether directed intracoronary infusion of darbepoetin-α into ischemic myocardium before reperfusion would reduce infarct size or post-infarct remodeling in STEMI patients.Eighty STEMI patients received one of the following treatments simultaneously with the first balloon inflation: intracoronary darbepoetin-α 300 μg (n = 40) or saline (n = 40), administered via the over-the-wire balloon system. The primary endpoint was infarct size estimated by serial cardiac enzyme levels after procedure. The secondary endpoints were (1) infarct size and proportion of salvaged myocardium measured with cardiac magnetic resonance (CMR) at baseline; (2) post-infarct remodeling (PIR), defined as an increase in left ventricular end-diastolic volume more than 20% at 4 months compared to the baseline on CMR; and (3) composite cardiovascular endpoints assessed at 4 months.The peak CK-MB [median 270.0 (interquartile range 139.8-356.3) versus 231.5 (131.0-408.5) ng/mL, P = 0.55] and troponin-I [128.5 (63.5-227.8) versus 109.0 (43.8-220.0) ng/mL, P = 0.52) ] did not differ between the darbepoetin-α and control group. Fifty-seven patients completed the baseline and 4-month follow-up CMR. There were no differences in infarct size [30.6 (18.1-49.8) versus 31.5 (22.5-47.3) cm³, P = 0.91), proportion of salvaged myocardium [26.7% (15.9-42.6%) versus 35.8% (22.4-48.8%), P = 0.12) or PIR (8.0% versus 6.7%, P = 0.62) between the two groups. Composite cardiovascular outcomes did not differ between the two groups.In conclusion, administration of intracoronary darbepoetin-α before reperfusion did not reduce infarct size or post-infarct remodeling in STEMI patients.

A US multicenter, retrospective, observational study of erythropoiesis-stimulating agent utilization in anemic, critically ill patients admitted to the intensive care unit

BACKGROUND

Anemia is a common comorbid condition among patients admitted to the intensive care unit (ICU). Darbepoietin alfa and epoetin alfa are erythropoiesis-stimulating agents (ESAs) used to manage anemia in the ICU, although neither drug has an indication in critically ill patients.

OBJECTIVE

This study describes ESA practice patterns in anemic, critically ill patients admitted to the ICU.

METHODS

A total of 19 hospitals participated in this US multicenter, retrospective, observational study of adult patients not receiving chronic hemodialysis who were admitted to the ICU for >or=24 hours between February 2005 and September 2005 and who received >or=1 dose of darbepoietin alfa or epoetin alfa. Data on ESA doses, dosing frequencies, hemoglobin levels, and red blood cell (RBC) transfusions were abstracted from electronic medical records.

RESULTS

A total of 438 patients were included in the analysis, of whom 201 (46%) were treated with darbepoietin alfa and 237 (54%) were treated with epoetin alfa. In the respective groups, similar proportions were male (121/201 [60%] and 126/237 [53%]) and white (146/195 [75%] and 140/184 [76%]); age was also similar (mean [SD], 62 [19] and 60 [18] years). The mean (SD) dose during the first week of ICU stay was 96.5 (40.5) microg with darbepoietin alfa and 33,439 (23,508) U with epoetin alfa. The most commonly prescribed dosing frequency with darbepoietin alfa was once weekly (88.1% of all prescribed doses), with a mean (SD) number of injections of 1.8 (1.75). With epoetin alfa, the most common dosing frequencies were 3 times weekly (35.9%), 1-time dosing (28.5%), and once weekly (24.0%), with a mean (SD) number of injections of 2.9 (4.2). In both groups, the duration of therapy was <or=1 week in ~50% of patients, and the mean change in hemoglobin concentration was 0.8 g/dL. Overall, 47% (darbepoietin alfa) and 44% (epoetin alfa) of patients were RBC transfusion independent (ie, did not require a transfusion during their ICU or hospital stay) after receiving the first ESA dose.

CONCLUSION

Based on these results, it is apparent that the practice patterns associated with ESA treatment of critically ill patients admitted to the ICU between February 2005 and September 2005 were highly variable.

[Is there still a role for recombinant erythropoietin in the management of anaemia of critical illness?]

There is a high prevalence of anaemia among patients admitted to the intensive care unit (ICU), and it may have a negative effect on patient's outcome. The most common treatment for anaemia in the ICU patient is allogeneic blood transfusion (ABT), yet it has been found to be a risk factor associated with an increased risk of morbidity and mortality in critical care patients. As a reduction of erythropoietin secretion and action is observed in most ICU patients, the administration of (rHuEPO) has emerged as a therapeutic option. Unfortunately, the results from different studies show that rHuEPO treatment results in a small reduction of ABT requirements when "restrictive" transfusion criteria are applied, which has only been supported by three of the studies. Yet this did not result in a decreased mortality rate, except for patients with a diagnosis on admission of trauma in two studies, even though one study reported a dose-dependent increase of thrombotic vascular events among patients without thromboprophylaxis. Altogether, clinical data suggest a role for rHuEPO in the treatment of anaemia in trauma patients, especially in those sustaining neurotrauma, whereas for non-trauma patients without an approved indication, rHuEPO administration is an expensive approach, does not seem to improve outcome, and might result in serious adverse effects. Consequently, more basic and clinical studies are required to ascertain which patients are more likely to benefit from these treatments, as well as to identify the optimal doses and administration schedules, and iron administration.

Anemia of critical illness

Anemia of critical illness, a commonly encountered clinical situation, is hematologically similar to that of chronic anemia, except that the onset is generally sudden. The etiology is usually multifactorial, occurring as a consequence of direct inhibitory effects of inflammatory cytokines, erythropoietin deficiency, blunted erythropoietic response, blood loss, nutritional deficiencies, and renal insufficiency. Although anemia is not well tolerated by critically ill patients, aggressive treatment of anemia can be just as detrimental as no treatment. Different types of anemia may coexist in a patient in the intensive care unit, making diagnosis and differentiation among these anemias complex, therefore requiring good diagnostic skills. Although several therapeutic options are available to treat anemia, critically ill patients often receive a transfusion, and yet, most recent studies indicate that blood transfusions in critically ill patients are associated with worse outcomes, including higher morbidity and mortality. These studies have generated interest in the administration of exogenous erythropoietin and iron therapy. Unfortunately, the accurate determination of iron status can be a rather difficult task, an undertaking that is made even more difficult by the presence of comorbid conditions that can affect the commonly used parameters for guiding iron therapy. The use of erythropoiesis-stimulating agents is rapidly gaining acceptance, although they also present potential problems of their own.

Recent Publications on Medications and Pharmacy

Hospital Pharmacy presents this feature to keep pharmacists abreast of new publications in the medical/pharmacy literature. Articles of interest will be abstracted monthly regarding a broad scope of topics.