Ferric gluconate is highly efficacious in anemic hemodialysis patients with high serum ferritin and low transferrin saturation: results of the Dialysis Patients' Response to IV Iron with Elevated Ferritin (DRIVE) Study

Safety issues with intravenous iron products in the management of anemia in chronic kidney disease

Anemia is a very common clinical problem in patients with chronic kidney disease (CKD) and is associated with increased morbidity and mortality in these patients. Erythropoietin is a hormone synthesized that is deficient in the majority of patients with advanced kidney disease, thereby predisposing these patients to anemia. The other cause of anemia is deficiency of iron. Iron deficiency anemia is common in people with CKD and its importance in supporting erythropoiesis is unquestioned, especially in those patients treated with erythropoietin. Intravenous iron is frequently used to treat anemia in CKD patients and is very efficacious in increasing hemoglobin but at the same time there are some safety issues associated with it. The objective of this review is to assess the frequency of adverse drug events associated with four different iron formulations: two iron dextran products known as high and low molecular weight iron dextran, iron sucrose, and sodium ferric gluconate complex. Several electronic databases were searched. In general, with the exception of high molecular weight iron dextran, serious or life-threatening adverse events appeared rare. Iron sucrose has the least reported adverse events and high molecular weight iron dextran has the highest number of reported adverse events. Low molecular weight iron dextran and ferric gluconate fall in between these two for number of adverse drug events.

Combined high serum ferritin and low iron saturation in hemodialysis patients: the role of inflammation

BACKGROUND

Serum ferritin, frequently used as a marker of iron status in individuals with chronic kidney disease, is also an inflammatory marker. The concurrent combination of high serum ferritin and low iron saturation ratio (ISAT) usually poses a diagnostic dilemma. We hypothesized that serum ferritin > or =500 ng/ml, especially in the seemingly paradoxical presence of ISAT level <25%, is more strongly associated with inflammation than with iron in maintenance hemodialysis (MHD) patients.

DESIGN, SETTING, AND PARTICIPANTS

In 789 MHD patients in the Los Angeles area, the association of serum ferritin > or =500 ng/ml with inflammatory markers, including IL-6 (IL-6) and C-reactive protein levels, and malnutrition-inflammation score (MIS) was examined.

RESULTS

After multivariate adjustment for case-mix and other measures of malnutrition-inflammation complex, MHD patients with serum ferritin > or =500 ng/ml and ISAT <25% had higher odds ratio for serum C-reactive protein > or =10 mg/L. The area under the receiver operating characteristic curves for the continuum of ISAT and IL-6 in detecting a serum ferritin > or =500 ng/ml were identical (0.57 versus 0.56, P = 0.7). The combination of IL-6 with ISAT yielded a higher area under the receiver operating characteristic curve (0.61) than either ISAT or IL-6 alone (P = 0.03 and P = 0.02, respectively).

CONCLUSION

In MHD patients, ferritin values above 500 ng/ml, especially in paradoxical conjunction with low ISAT, are associated with inflammation. Strategies to dissociate inflammation from iron metabolism to mitigate the confounding impact of inflammation on iron and to improve iron treatment responsiveness may improve anemia management in chronic kidney disease.

Erythropoietin, iron depletion, and relative thrombocytosis: a possible explanation for hemoglobin-survival paradox in hemodialysis

BACKGROUND

High doses of human recombinant erythropoietin (rHuEPO) to achieve hemoglobin levels greater than 13 g/dL in patients with chronic kidney disease appear to be associated with increased mortality.

STUDY DESIGN

We conducted logistic regression and survival analyses in a retrospective cohort of long-term hemodialysis patients to examine the hypothesis that the induced iron depletion with resultant relative thrombocytosis may be a possible contributor to the link between the high rHuEPO dose-associated hemoglobin level of 13 g/dL or greater and mortality.

SETTING & PARTICIPANTS

The national database of a large dialysis organization (DaVita) with 40,787 long-term hemodialysis patients during July to December 2001 and their survival up to July 2004 were examined.

PREDICTORS

Hemoglobin level, platelet count, and administered rHuEPO dose during each calendar quarter.

OUTCOMES & OTHER MEASUREMENTS

Case-mix-adjusted 3-year all-cause mortality and measures of iron stores, including serum ferritin and iron saturation ratio.

RESULTS

Higher platelet count was associated with lower iron stores and greater prescribed rHuEPO dose. Compared with a hemoglobin level of 12 to 13 g/dL, a hemoglobin level of 13 g/dL or greater was associated with increased mortality in the presence of relative thrombocytosis, ie, platelet count of 300,000/microL or greater (case-mix-adjusted death-rate ratio, 1.21; 95% confidence limits, 1.02 to 1.44; P = 0.03) as opposed to the absence of relative thrombocytosis (death-rate ratio, 1.04; 95% confidence limits, 0.98 to 1.08; P = 0.1). A prescribed rHuEPO dose greater than 20,000 U/wk was associated with a greater likelihood of iron depletion (iron saturation ratio < 20%) and relative thrombocytosis (case-mix-adjusted odds ratio, 2.53; 95% confidence limits, 2.37 to 2.69; and 1.36; 95% confidence limits, 1.30 to 1.42, respectively; P < 0.001) and increased mortality during 3 years (death-rate ratio, 1.59; 95% confidence limits, 1.54 to 1.65; P < 0.001).

LIMITATIONS

Our results may incorporate uncontrolled confounding. Achieved hemoglobin level may have different mortality predictability than targeted hemoglobin level.

CONCLUSIONS

Iron depletion and associated relative thrombocytosis might contribute to increased mortality when administering high rHuEPO doses to achieve hemoglobin levels of 13 g/dL or greater in long-term hemodialysis patients. Randomized trials are needed to test these observational associations.

Safety of ferumoxytol in patients with anemia and CKD

BACKGROUND

Iron deficiency anemia is a common complication in patients with chronic kidney disease (CKD). Currently available intravenous (IV) iron replacement therapies have either inconvenient regimens of administration or adverse event profiles that limit their utility in the outpatient setting. Ferumoxytol is a novel, semisynthetic, carbohydrate-coated, superparamagnetic iron oxide nanoparticle that is administered IV as an injection. The main objective of this study was to assess the safety of ferumoxytol for the treatment of patients with CKD stages 1 to 5 and 5D.

STUDY DESIGN

Phase 3, randomized, double-blind, placebo-controlled, crossover, multicenter study of a single 510-mg dose of ferumoxytol versus saline as placebo.

SETTING & PARTICIPANTS

750 patients with CKD stages 1 to 5 and 5D.

INTERVENTION

An IV injection of either 17 mL of ferumoxytol or saline placebo over 17 seconds on day 0 and the alternate agent on day 7.

OUTCOMES & MEASUREMENTS

Descriptive comparison of adverse events, laboratory tests, and vital signs.

RESULTS

Of 750 randomly assigned patients with CKD, 60% were not on dialysis therapy. 713 patients received ferumoxytol, and 711 received placebo. There were 420 adverse events reported; 242 in 152 patients (21.3%) with ferumoxytol and 178 in 119 patients (16.7%) with placebo. The incidence of related adverse events was 5.2% with ferumoxytol and 4.5% with placebo. The most common related adverse events after each treatment included symptoms related to the injection/infusion site, dizziness, pruritus, headache, fatigue, and nausea. Serious adverse events occurred in 21 patients (2.9%) after ferumoxytol and 13 patients (1.8%) after placebo. Serious related adverse events were observed in 1 patient (0.1%) after each treatment. There was no meaningful decrease in blood pressure after administration of ferumoxytol or placebo.

LIMITATIONS

Follow-up was 7 days after each study treatment.

CONCLUSIONS

Ferumoxytol is well tolerated and has a safety profile similar to placebo in anemic patients with CKD stages 1 to 5 and 5D.

Intravenous Iron Therapy: A Summary of Treatment Options and Review of Guidelines

Iron replacement for iron-deficiency anemia has historically been accomplished with the use of oral iron therapy. Although oral iron is appropriate for most iron-deficiency anemia patients, many patients do not respond to or may be intolerant of oral iron, or may experience bleeding of sufficient magnitude to require higher iron doses than that achievable with oral iron. Intravenous iron therapy is a useful option for these latter patients. Three intravenous iron products are recommended: low-molecular weight iron dextran (INFeD), ferric gluconate (Ferrlecit), and iron sucrose (Venofer). These intravenous iron products have superior safety profiles compared to high-molecular weight iron dextran. The Food and Drug Administration's approval of erythropoietic-stimulating agents to treat certain types of anemia has increased usage of intravenous iron for functional iron deficiency. This review summarizes the current status of intravenous iron products and discusses their advantages and disadvantages in treating both absolute and functional iron deficiency.

Intravenous iron exacerbates oxidative DNA damage in peripheral blood lymphocytes in chronic hemodialysis patients

Patients undergoing maintenance hemodialysis have elevated markers of oxidative stress, but the reasons for this are not fully understood. Intravenous administration of iron, which many of these patients receive, may provoke the generation of bioactive iron, which enhances oxidative stress and lipid peroxidation. In this study, 110 hemodialysis patients were randomly assigned to five groups that were administered single intravenous doses of iron sucrose, ranging from 20 to 500 mg. A time- and dosage-dependent rise in lymphocyte 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in lymphocyte DNA, a marker of oxidative DNA damage, with a significant increase at 2 h after intravenous iron of > or = 200 mg (P < 0.05). Four weeks later, patients were randomly assigned to weekly iron sucrose (100 mg of elemental iron) or saline for 12 wk, and 89 patients completed the study. Mean lymphocyte 8-OHdG content was significantly higher in patients receiving intravenous iron compared with control subjects (P < 0.05), especially in those with ferritin levels > 500 microg/L. In addition, flow cytometric techniques revealed increased production of reactive oxygen species in lymphocytes among those treated with intravenous iron. Treatment with intravenous iron but not saline was also associated with decreased plasma ascorbate and alpha-tocopherol levels and increased oxidized glutathione/reduced glutathione ratio (P < 0.05). In summary, intravenous iron sucrose provokes oxidative damage to peripheral blood lymphocyte DNA in hemodialysis patients, especially among those with high levels of ferritin.

The role of correction of anaemia in patients with congestive heart failure: a short review

Many patients with Congestive Heart Failure (CHF) are anaemic. This anaemia is associated with more severe CHF and a higher incidence of mortality, hospitalisation and morbidity. The only way to prove that the anaemia is causing this worsening of CHF is to correct it. We review here some of the published papers about correction of anaemia. Many studies show a positive effect of Erythropoietin (EPO) or its' derivatives when administered in combination with oral or IV iron, with improvements in left and right ventricular systolic and diastolic function, dilation and hypertrophy and renal function. In addition, a reduction in hospitalisations, diuretic dose, pulmonary artery pressure, plasma volume, heart rate, serum Brain Natriuretic Peptide levels, the inflammatory marker Interleukin 6, soluble Fas ligand--a mediator of apoptosis, and improvements in New York Heart Association class, exercise capacity, oxygen utilization, caloric intake, Quality of Life and the activity of Endothelial Progenitor Cells, have been observed. Iron deficiency may also play an important role in this anaemia, since improvements in CHF have also been reported following treatment with IV iron alone. However, until the ongoing large placebo-controlled studies of the EPO derivative darbepoetin or IV iron are completed, we will not know whether these treatments really influence CHF outcome.

Intravenous iron: from anathema to standard of care

A growing body of literature supports the use of intravenous iron as a compliment to erythropoiesis stimulatory therapy and in a significant number of disease states where iron is necessary and oral iron is ineffective or not tolerated. The differences in efficacy, safety, and clinical nature of serious adverse events that occur with the various iron preparations are poorly understood. Misinterpretation of adverse events leads to underutilization of this important treatment modality. Understanding the history of the development and use of intravenous iron is crucial to appreciate its importance in the management of anemias of dialysis, cancer, and cancer chemotherapy and properly assess side effects and toxicity. The benefits seen with intravenous iron therapy are independent of the pretreatment levels of serum ferritin, iron, total iron binding capacity, and percent transferrin saturation. Intravenous iron has been shown to overcome hepcidin induced iron restricted erythropoiesis in iron-replete patients. Available clinical and experimental data suggest that increased utilization of intravenous iron should be considered.

Anemia of Chronic Kidney Disease

Chronic kidney disease may result in complete kidney failure and contribute to many other health issues. Anemia is a logical consequence of the disease because the kidneys are the primary source of erythropoietin, the hormone that acts to stimulate red blood cell production in the bone marrow. All patients with chronic kidney disease are at risk for anemia, and treating anemia is extremely important to their health and well-being. Preventing or reversing the effects of anemia on the heart may decrease morbidity and mortality and improve quality of life. Many patients fail to receive treatment for anemia before requiring renal replacement therapy for end-stage renal disease. Pharmacists can play a vital role in screening, evaluating, designing proper treatment regimens, and monitoring patients with anemia of chronic kidney disease. Current recommendations regarding anemia are reviewed, including evaluation, pharmacotherapeutic agents, monitoring parameters, and goals of therapy.

Thrombosis with erythropoietic stimulating agents-does iron-deficient erythropoiesis play a role?

Thrombocytosis is common in iron deficiency and resolves following iron repletion. Increased platelet number, whether from iron deficiency or from other causes, may increase the risk of thrombovascular events. One mechanism thought to mediate iron deficiency-induced thrombocytosis is increased erythropoietin production. Similarly, erythropoietic stimulating agents (ESA) have long been known to increase platelet number and frequently lead to functional or absolute iron deficiency. This state of relative or absolute iron deficiency may be the mechanism whereby ESA increase the platelet count. If correct, co-administration of iron should prevent or diminish ESA-driven thrombocytosis. Data from the DRIVE trial in hemodialysis patients do, in fact, suggest that this is the case. Platelet counts in patients receiving IV iron decreased, while they remained unchanged in patients not given iron (mean change -29,000/microl vs. -0/microl; p = 0.017). Other supporting data have been observed in IV iron trials in oncology patients. The harm from higher hemoglobin targets and higher ESA doses may be mediated in part through induction of iron deficiency and thrombocytosis. The major anemia trials of ESAs have not reported platelet data, but should examine the relationship of platelet count, iron deficiency, IV iron administration, and cardiovascular events in greater detail.

The optimal hemoglobin in dialysis patients- a critical review

The introduction of recombinant human erythropoietin treatment has been one of the most important advances in the treatment of dialysis patients and others with chronic kidney disease (CKD). Treatment of CKD anemia has been shown to reduce the need for blood transfusions and to improve quality of life. However, the target hemoglobin level in treating patients is currently controversial. This is because of the recent publication of two randomized controlled studies in nondialysis CKD patients, the CREATE and CHOIR studies, as well as an accompanying meta-analysis. These studies demonstrate increase risk for death and cardiovascular complications when aiming for a hemoglobin (Hgb) level of >12 g/dl. In light of this new data, the National Kidney Foundation Kidney Disease Outcomes Quality Initiative anemia guidelines are being revised. The Food and Drug Administration has issued a Black Box warning and indicated that hemoglobin levels do not exceed 12 g/dl. While observational data suggest a benefit for higher hemoglobin levels, these studies have limitations because of their retrospective design and the potential effect of confounding factors. Hence, reliance on observational studies to guide CKD anemia treatment is a potentially flawed and hazardous process. In this editorial we propose that the current literature does not support an upper Hgb target above 12 g/dl. We also suggest that the current reimbursement system for erythropoiesis stimulating agent treatment potentially encourages unsafe overtreatment.

Iron and anemia in human biology: a review of mechanisms

The biology of iron in relation to anemia is best understood by a review of the iron cycle, since the majority of iron for erythropoiesis is provided by iron recovered from senescent erythrocytes. In iron-deficiency anemia, storage iron declines until iron delivery to the bone marrow is insufficient for erythropoiesis. This can be monitored with clinical indicators, beginning with low plasma ferritin, followed by decreased plasma iron and transferrin saturation, and culminating in red blood cells with low-Hb content. When adequate dietary iron is provided, these markers show return to normal, indicating a response to the dietary supplement. Anemia of inflammation (also known as anemia of chronic disease, or ACD) follows a different course, because in this form of anemia storage iron is often abundant but not available for erythropoiesis. The diagnosis of ACD is more difficult than the diagnosis of iron-deficiency anemia, and often the first identified symptom is the failure to show a response to a dietary iron supplement. Confirmation of ACD is best obtained from elevated markers of inflammation. The treatment of ACD, which typically employs erythropoietin (EPO) supplements and intravenous iron (i.v.-iron), is empirical and often falls shorts of therapeutic goals. Dialysis patients show a complex pattern of anemia, which results from inadequate EPO production by the kidney, inflammation, changes in nutrition, and blood losses during treatment. EPO and i.v.-iron are the mainstays of treatment. Patients with heart failure can be anemic, with incidence as high as 50%. The causes are multifactorial; inflammation now appears to be the primary cause of this form of anemia, with contributions from increased plasma volume, effects of drug therapy, and other complications of heart disease. Discerning the mechanisms of anemia for the heart failure patient may aid rational therapy in each case.

Parenteral iron with erythropoiesis-stimulating agents for chemotherapy-induced anemia

Purpose. To discuss the clinical issues we addressed in the development of our institutional guidelines regarding the assessment of iron stores for cancer- and treatment-related anemia and the administration of parenteral iron with erythropoiesis-stimulating agents (ESAs).

Data sources. Studies published from January 1995 to August 2007 were identified by computer searches of Medline and hand searching of bibliographies of the articles identified via the computer searches. The current clinical practice guidelines were identified by computer searches of the web sites for national professional organizations that represent health care professionals who treat patients with cancer.

Results of data analysis. Hematopoietic responses demonstrate that epoetin alfa and darbepoetin alfa provide similar outcomes for patients with chemotherapy-induced anemia (CIA); however, up to 50% of patients receiving these agents fail to adequately respond. Functional iron deficiency defined as a state of iron-restricted erythropoiesis is likely the primary contributor to the lack of response. Hematopoietic responses following ESA therapy with parenteral iron are substantially higher compared to response with no or oral iron.

Conclusions. Iron stores should be assessed in all patients with cancer- or treatment-related anemia and parenteral iron should be administered to patients receiving ESA therapy to improve hematopoietic response. A unique algorithm that summarizes our institutional guidelines to assess iron stores and administer parenteral iron with ESA therapy in patients with CIA is included. J Oncol Pharm Practice (2008) 14: 5—22.

Erythropoietin stimulating agents in the management of anemia of chronic kidney disease

Anemia is a very common clinical problem in patients with chronic kidney disease (CKD) and is associated with increased morbidity and mortality in these patients. Erythropoietin is a hormone synthesized in the kidney responsible for red blood cell maturation in the bone marrow. It is deficient in the majority of patients with advanced kidney disease thereby predisposing to anemia. Since the approval of recombinant human erythropoietin (epoetin alfa) by the US FDA in 1989, epoetin alfa and similar agents now collectively known as erythropoietin stimulating agents (ESA) have become the standard of care for the treatment of the erythropoietin-deficient anemia that occurs in most patients with CKD. In this review, we have outlined the considerations that need to be taken into account when prescribing ESA for the treatment of anemia in CKD.

Upper limit of serum ferritin: misinterpretation of the 2006 KDOQI anemia guidelines

Intravenous iron treatment in hemodialysis patients improves response to recombinant human erythropoietin and facilitates achievement of targets for hemoglobin and hematocrit. Excessive treatment, however, could expose patients to risks related to iron overload and oxidative stress. Therefore, international treatment guidelines generally recommend that intravenous (i.v.) iron be discontinued when serum ferritin is >500-1,000 ng/ml. In the current review, relevant issues that inform decisions as to what levels of serum ferritin should be used as the upper limit for treatment are considered. A conclusion is reached that the current published literature is inadequate for developing evidence-based guidelines on this issue. Instead, clinical judgment is critical to properly weigh risks and benefits of i.v. iron treatment, and to determine whether iron treatment is appropriate for a given patient with higher levels of iron tests.

Ferric gluconate reduces epoetin requirements in hemodialysis patients with elevated ferritin

The Dialysis Patients Response to IV Iron with Elevated Ferritin (DRIVE) study demonstrated the efficacy of intravenous ferric gluconate to improve hemoglobin levels in anemic hemodialysis patients who were receiving adequate epoetin doses and who had ferritin levels between 500 and 1200 ng/ml and transferrin saturation (TSAT) < or = 25%. The DRIVE-II study reported here was a 6-wk observational extension designed to investigate how ferric gluconate impacted epoetin dosage after DRIVE. During DRIVE-II, treating nephrologists and anemia managers adjusted doses of epoetin and intravenous iron as clinically indicated. By the end of observation, patients in the ferric gluconate group required significantly less epoetin than their DRIVE dose (mean change of -7527 +/- 18,021 IU/wk, P = 0.003), whereas the epoetin dose essentially did not change for patients in the control group (mean change of 649 +/- 19,987 IU/wk, P = 0.809). Mean hemoglobin, TSAT, and serum ferritin levels remained higher in the ferric gluconate group than in the control group (P = 0.062, P < 0.001, and P = 0.014, respectively). Over the entire 12-wk study period (DRIVE plus DRIVE-II), the control group experienced significantly more serious adverse events than the ferric gluconate group (incidence rate ratio = 1.73, P = 0.041). In conclusion, ferric gluconate maintains hemoglobin and allows lower epoetin doses in anemic hemodialysis patients with low TSAT and ferritin levels up to 1200 ng/ml.

Serum albumin is strongly associated with erythropoietin sensitivity in hemodialysis patients

BACKGROUND AND OBJECTIVES

In hemodialysis patients, the hematological response to erythropoietin (epo) is variable and clinical factors that explain this variability are incompletely understood. We tested the hypothesis that the variability in hemoglobin (Hgb) response (epo sensitivity) is determined by key nutritional, inflammation, and oxidative stress markers.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Eighty-two consecutive patients on hemodialysis had 3 consecutive monthly predialysis evaluations of Hgb, total white blood cell (WBC) count, serum albumin, malondialdehyde (MDA), and monocyte chemoattractant protein-1 (MCP1). We analyzed the time course of Hgb in relationship to serum albumin, WBC, MDA, MCP1, epo and iron administration, and tests of iron sufficiency in a linear growth curve model.

RESULTS

Subjects with higher Hgb had a fall in Hgb and vice versa, regressing to a mean Hgb (SD) of 11.8 g/dl (1.8 g/dl). Whereas the average slope of Hgb was flat, the SD of slopes was 0.63 g/dl, which explained 39% of the variance in Hgb. Nonuse of epo was associated with a mean Hgb change of -0.18 g/dl (95% confidence interval [CI] -0.26 to -0.10) per 10,000 IU epo/mo (P < 0.05). Epo use was associated with steeper rate of change at 0.04 g/dl per mo per 10,000 IU (95% CI 0.01 to 0.07) (P < 0.01). Hgb at baseline was 0.73 g/dl higher for each 1-g/dl increase in albumin, and the rate of change increased by 0.49 g/dl per mo for each 1-g/dl increase in albumin concentration. WBC, MDA, or MCP1 had no role in predicting the baseline Hgb or its change over time.

CONCLUSIONS

Serum albumin concentration is an important predictor of both baseline Hgb and epo sensitivity in chronic hemodialysis patients. Factors that improve serum albumin may also improve Hgb in hemodialysis patients.

Erythropoiesis-stimulating agent hyporesponsiveness

Approximately 5-10% of patients with chronic kidney disease demonstrate hyporesponsiveness to erythropoiesis-stimulating agents (ESA), defined as a continued need for greater than 300 IU/kg per week erythropoietin or 1.5 mug/kg per week darbepoetin administered by the subcutaneous route. Such hyporesponsiveness contributes significantly to morbidity, mortality and health-care economic burden in chronic kidney disease and represents an important diagnostic and management challenge. The commonest causes of ESA resistance are non-compliance, absolute or functional iron deficiency and inflammation. It is widely accepted that maintaining adequate iron stores, ideally by administering iron parenterally, is the most important strategy for reducing the requirements for, and enhancing the efficacy of ESA. There have been recent epidemiologic studies linking parenteral iron therapy to an increased risk of infection and atherosclerosis, although other investigations have refuted this. Inflammatory ESA hyporesponsiveness has been reported to be improved by a number of interventions, including the use of biocompatible membranes, ultrapure dialysate, transplant nephrectomy, ascorbic acid therapy, vitamin E supplementation, statins and oxpentifylline administration. Other variably well-established causes of ESA hyporesponsiveness include inadequate dialysis, hyperparathyroidism, nutrient deficiencies (vitamin B12, folate, vitamin C, carnitine), angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, aluminium overload, antibody-mediated pure red cell aplasia, primary bone marrow disorders, myelosuppressive agents, haemoglobinopathies, haemolysis and hypersplenism. This paper reviews the causes of ESA hyporesponsiveness and the clinical evidence for proposed therapeutic interventions. A practical algorithm for approaching the investigation and management of patients with ESA hyporesponsiveness is also provided.

Use of erythropoiesis-stimulating agents in patients with anemia of chronic kidney disease: overcoming the pharmacological and pharmacoeconomic limitations of existing therapies

Stage 3 chronic kidney disease (CKD), which is characterized by a glomerular filtration rate of 30 to 60 mL/min/1.73 m2 (reference range, 90-200 mL/min/1.73m2 for a 20-year-old, with a decrease of 4 mL/min per decade), affects approximately 8 million people in the United States. Anemia is common in patients with stage 3 CKD and, if not corrected, contributes to a poor quality of life. Erythropoiesis-stimulating agents (ESAs), introduced almost 2 decades ago, have replaced transfusions as first-line therapy for anemia. This review summarizes the current understanding of the role of ESAs in the primary care of patients with anemia of CKD and discusses pharmacological and pharmacoeconomic issues raised by recent data. Relevant studies in the English language were identified by searching the MEDLINE database (1987-2006). Two ESAs are currently available in the United States, epoetin alfa and darbepoetin alfa. More frequent dosing with epoetin alfa is recommended by the labeled administration guidelines because it has a shorter half-life than darbepoetin alfa. Clinical experience also supports extended dosing intervals for both these ESAs. Use of ESAs in the management of anemia of CKD is associated with improved quality of life, increased survival, and decreased progression of renal failure. Some evidence suggests that ESAs have a cardioprotective effect. However, correction of anemia to hemoglobin levels greater than 12 g/dL (to convert to g/L, multiply by 10) appears to increase the risk of adverse cardiac outcomes and progression of kidney disease in some patients. The prescription of ESAs in the primary care setting requires an understanding of the accepted use of these agents, the associated pharmacoeconomic challenges, and the potential risks. This review considers the need to balance effective ESA dosing intervals against the potential risks of treatment.

Pharmacist's role in managing anemia in patients with chronic kidney disease: potential clinical and economic benefits

PURPOSE

Barriers to the treatment of anemia in patients with chronic kidney disease (CKD), the role of pharmacists in screening patients for anemia and developing guidelines for the use of anemia therapies in patients with CKD, the goals of and considerations in developing pharmacist-managed anemia management clinics, and the potential benefits of these clinics are described.

SUMMARY

The complexity of patients with CKD, patient nonadherence to the treatment regimen, a shortage of nephrologists, and a lack of familiarity with clinical practice guidelines and recommendations for treating anemia in these patients are possible barriers to the treatment of anemia. Pharmacists can play a role in improving the treatment of anemia in patients with CKD by screening for anemia, developing guidelines for the use of anemia therapies, and providing patient education to promote adherence to the treatment regimen. The optimal upper limit for hemoglobin concentration during treatment with erythropoietin-stimulating agents (ESA) in patients with CKD remains to be determined, but it should not routinely exceed 13.0 g/dL. Extended dosing of darbepoetin alfa and the new agent continuous erythropoiesis receptor activator appears effective. Iron status often is not assessed in patients with CKD because of difficulty interpreting iron laboratory values and identifying iron deficiency. The usefulness of iron supplementation is not limited to patients with iron deficiency. The intravenous (i.v.) or oral route of administration may be used for iron supplementation in predialysis patients and peritoneal dialysis patients, but the i.v. route is recommended for hemodialysis patients. Adverse effects and drug interactions limit the use of oral iron supplements. Administration of parenteral iron is time consuming and accompanied by concerns about iron accumulation and uncertainty about the optimal maximum serum ferritin concentration. Improved access to care and clinical outcomes and reduced costs have been documented in pharmacist-managed anemia management clinics.

CONCLUSION

Pharmacists can help overcome barriers to treating anemia in patients with CKD. Clinical and economic benefits are associated with pharmacist-managed anemia management clinics.

Predictors of the response to treatment in anemic hemodialysis patients with high serum ferritin and low transferrin saturation

Treating hemodialysis patients to combat anemia corrects hemoglobin but exacerbates iron deficiency by utilizing iron stores. Patients needing iron should receive this by intravenous (i.v.) means. The Dialysis patients' Response to IV iron with Elevated ferritin (DRIVE) trial investigated the role of i.v. iron in anemic patients with high ferritin, low transferrin saturation, and adequate epoetin doses. We examined whether baseline iron and inflammation markers predict the response of hemoglobin to treatment. Patients (134) were randomized to no added iron or to i.v. ferric gluconate for eight consecutive hemodialysis sessions spanning 6 weeks with epoetin increased by 25% in both groups. The patients started with hemoglobin less than or equal to 11 g/dl, ferritin between 500 and 1200 ng/ml, and transferrin saturation of less than 25%. Significantly, patients with a reticulocyte hemoglobin content greater than or equal to 31.2 pg were over five times more likely to achieve a clinically significant increase in hemoglobin of greater than 2 g/dl. Lower reticulocyte hemoglobin contents did not preclude a response to i.v. iron. Significantly higher transferrin saturation or lower C-reactive protein but not ferritin or soluble transferrin receptor levels predicted a greater response; however their influence was not clinically significant in either group. We conclude that none of the studied markers is a good predictor of response to anemia treatment in this patient sub-population.

Role of oral iron in the management of long-term hemodialysis patients

BACKGROUND

The literature contends that oral iron supplementation is relatively ineffective in patients who are on long-term hemodialysis (HD), and intravenous iron is the superior form of supplementation.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

Data were prospectively abstracted from a cross-sectional cohort of all patients in the long-term in-center HD program at St. Michael's Hospital (SMH) from April 1, 2003, to April 1, 2004. Laboratory data were measured monthly. SMH data were compared with those in eight other centers in the Toronto Region Dialysis Registry.

RESULTS

A total of 93% of the 151 patients tolerated oral iron. Eighty-eight (58%) patients received oral iron exclusively, and 60 (40%) patients received intravenous iron with or without oral iron. Of the patients who received oral iron exclusively, 73% maintained a hemoglobin of > or =110 g/L and 93% maintained a hemoglobin of > or =100 g/L. A total of 74% had an iron saturation > or =20%, and 36% had a ferritin level >100 g/L. Among the patients who were on oral iron alone and had hemoglobin of > or =110 g/L, the same amount of erythropoietin was used regardless of ferritin levels (P = 0.17), but less erythropoietin was used when they reached the target for either iron saturation or both iron indices (P = 0.02 and 0.03, respectively). Among the centers in the Toronto Region Dialysis Registry, hemoglobin levels and erythropoietin dosages did not differ among the three centers that predominantly used oral iron versus the six centers that predominantly use intravenous iron (P = 0.46 and 0.95, respectively).

CONCLUSIONS

Oral iron is a well-tolerated and effective form of iron supplementation in long-term HD patients.