Trends in Intravenous Iron Use Among Dialysis Patients in the United States (1994-2002)

Comparative iron management in hemodialysis and peritoneal dialysis patients: a systematic review

Background

Patients with kidney failure undergoing dialysis often suffer from anemia. Iron deficiency, along with a shortage in erythropoietin, is a common cause. Peritoneal dialysis (PD) patients may have a different iron metabolism compared to hemodialysis (HD) patients. This study aims to compare both dialysis modalities regarding their differences in iron management.

Methods

PubMed (MEDLINE) and Embase were screened for randomized controlled trials and observational studies including both patients on HD or PD with information on iron management. Outcomes for iron management for this systematic review included: prevalence of supplementation, route of administration, dose, frequency and hemoglobin and iron status parameters.

Results

15 eligible studies (930,436 patients), of which 8 cohort and 7 cross-sectional, were analyzed. The prevalence of intravenous (IV) iron supplementation ranged from 11.7% to 84.4% in HD patients, compared to 1.6% to 49.0% in PD patients. Ten studies reported that HD patients only received IV iron, while five studies reported this for PD patients. For oral iron supplementation, three studies involved HD patients, whereas seven studies involved PD patients. The cumulative monthly IV iron dose ranged from 108 to 750 mg in the HD group, compared to 65 to 250 mg in the PD group. Hemoglobin levels ranged from 10.0 to 12.0 g/dL in HD patients, versus 9.6 to 11.9 g/dL in PD patients.

Conclusion

Iron management differs between HD and PD patients, with HD patients receiving higher doses and more frequent IV iron. There was significant heterogeneity in the outcomes between the studies, primarily due to the lack of a uniform global policy on iron management. Despite these differences, hemoglobin levels and iron status parameters were comparable between the two groups. Future research should explore the underlying mechanisms and broader impacts of iron treatment, including patient-reported outcomes, to optimize anemia management and improve quality of life for dialysis patients.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022336970.

Intravenous iron sucrose for children with iron deficiency anemia: a single institution study

BACKGROUND

Intravenous iron sucrose is not recommended by its manufacturers for use in children despite extensive safety and efficacy data in adults.

METHODS

We reviewed the experience of our department between January, 2011 and February, 2014 with the use of intravenous iron sucrose in children ≤14 years of age who failed in oral iron therapy for iron deficiency anemia (IDA).

RESULTS

Twelve children (6 females) aged 1.2-14 years (median age 8.9 years) received at least one dose of intravenous iron sucrose. Ten patients had IDA inadequately treated or non-responsive to oral iron therapy. One patient received therapy for blood transfusion avoidance and one for presumed iron refractory iron deficiency anemia (IRIDA). Iron sucrose infusions were given on alternate days up to three times per week. The number of infusions per patient ranged from 2 to 6 (median, 3), the individual doses from 100 mg to 200 mg (median, 200 mg), and the total doses from 200 mg to 1200 mg (median, 400 mg). Iron sucrose was effective in raising the hemoglobin concentration to normal in all patients with IDA, i.e., from 7.6±2.38 g/dL to 12.4±0.64 g/dL, within 31-42 days after the first infusion. The single patient with IRIDA demonstrated a 1.8 g/dL rise. Injection site disorders in three cases and transient taste perversion in one case were the only side effects.

CONCLUSION

Intravenous iron sucrose appears to be safe and very effective in children with IDA who do not respond or cannot tolerate oral iron therapy.

Impact of European medicines agency recommendations for hypersensitivity reactions on intravenous iron prescription in haemodialysis centres of the Lombardy region

BACKGROUND

The European Medicines Agency (EMA) has recommended measures to minimize the risk of hypersensitivity reactions (HSRs) to intravenous iron (IVFe). We analysed the effects of these recommendations on IVFe clinical management among haemodialysis centres (HDCs) in Lombardy, Italy.

MATERIALS AND METHODS

A questionnaire was sent to all 117 HDCs to collect information on centre characteristics, e.g. HDC type [hospital centre (HC) vs. centre with limited assistance (CAL)], presence/absence of intensive care unit (ICU) and/or emergency trained staff, IVFe therapy regarding molecules, administration modalities, side effects, and percentage variations in iron prescription between 2014 and 2013 (outcome, Δ-IVFe%). A linear regression model was applied to evaluate the focus effect (β) of HDC type on the outcome, controlling for possible confounding effects of the other characteristics.

RESULTS

Response rate was 73.5 %. IVFe therapy was used in 69.1 % (HDC range 11-100) of patients. Following EMA recommendations, prescription was reduced by 12.6 %, with the largest reduction observed in CALs. No severe HSRs were reported. HCs had more frequently an ICU [97.2 vs. 20 %, odds ratio (OR) = 63.6 (95 % confidence interval 15.56; 537.47), p < 0.001], emergency trained staff [97.2 vs. 61.2 %, OR = 10.7 (2.68; 85.33), p < 0.001] and instrumental facilities (91.7 vs. 58 %, OR = 5.8 (2.03; 23.55), p < 0.001] than CALs. Linear regression demonstrated a significant raw effect of HDC type on Δ- IVFe% [β =  19.6 (9.82; 30.63), p < 0.001]. No association was found when HDC type was adjusted for ICU-presence [β = 6.7 (-2.32; 18.30), p = 0.199] or for all-confounding factors [β = 5.6 (-5.50; 17.08), p = 0.337].

CONCLUSIONS

This survey shows a disparity in IVFe therapy prescription following EMA recommendations, which is largely influenced by the presence/absence of ICUs in HD centres.

Effective achievement of hemoglobin stability with once-monthly C.E.R.A. in peritoneal dialysis patients: a prospective study

Background

Correction of low hemoglobin (Hb) levels is associated with improved survival and greater quality of life in dialysis patients, but frequent administration of erythropoiesis stimulating agent (ESA) therapy is unsatisfactory for peritoneal dialysis patients.

Objective

The objective of this study was to assess Hb stability in an unselected population of maintenance peritoneal dialysis patients receiving once-monthly treatment with C.E.R.A., a continuous erythropoietin receptor activator.

Methods

In a prospective, non-interventional, single-arm study at 33 Germany dialysis centers, peritoneal dialysis patients with or without ESA treatment prior to study entry received once-monthly treatment with C.E.R.A. Hb stability was assessed by the proportion of patients for whom all measured Hb values during months 6–8 (the evaluation phase) were within the range 11–12, 11–13, 10–12 or 11–12.5 g/dL.

Results

220 patients received at least one dose of C.E.R.A. During the evaluation phase, 185 patients provided ≥1 Hb measurement (efficacy population) and 162 patients provided ≥2 Hb measurements (the modified efficacy population). The mean (SD) time between C.E.R.A. doses was 28.2 (7.2) days and mean (SD) C.E.R.A. dose was 109 (57) μg per application. Mean (SD) Hb level was 11.1 (1.4) g/dL at baseline and 11.5 (1.3) g/dL at the end of the study (modified efficacy population). The primary efficacy variable, all measured Hb values in the range 11–12 g/dL, was 18.4 % (34/185) and 14.8 % (24/162) in the efficacy and modified efficacy populations, respectively. The mean (SD) maximum intra-individual fluctuation in Hb level was 0.56 (0.50) g/dL in the efficacy population and 0.58 (0.49) g/dL in the modified efficacy population, with maximum intra-individual fluctuation ≤1 g/dL in 85.4 % (158/185) and 83.3 % (135/162) of patients, respectively. No adverse drug reactions were reported during the study.

Conclusion

In this large population of maintenance peritoneal dialysis patients, once-monthly administration of C.E.R.A. achieved a high degree of Hb stability and was well-tolerated.

[Intravenous iron during predialysis period improves anemia management and cardiovascular parameters in incident hemodialysis patients]

Individualized use of iron therapy (IT) and erythropoiesis-stimulating agents (ESA) may effectively correct anemia and its symptoms in CKD patients (Pts). The aim of this retrospective study was to precise the anemia management (AM) in incident HD Pts, and to compare Pts treated by intravenous (i.v.) IT and ESA during predialysis to those treated by oral IT and ESA on AM and cardiovascular parameters during the first year of HD. One hundred and two Pts performed their first dialysis in the unit, mean age 58.5 (15.9) years, 70% males, 27% diabetes. Ninety Pts started with a native arteriovenous fistula. Charlson comorbidity index was 7.3 (3.5). Mortality rate was 3% at one year. Hb level was at start 10.6 (1.7) and at one year 11.7 (1.1) g/dL (P<0.0001). DA injected every 2weeks was at the beginning at 107 (56) μg and then at 61 (46) (P<0.0001). i.v. IT injected every week was at the dosage of 87 (23) mg and then at 57 (40mg) per injection (P<0.001). Out of 102 Pts, 33 received i.v. IT during predialysis. These Pts started dialysis with a better Hb level: 11.1 (1.3) versus 10.4 (1.55) g/dL (P<0.01), had a TSAT at 50.0 (19.2) versus 30.1 (15.2) % (P<0.001), received less ESA 0.58 (0.28) versus 0.82 (0.37) μg/kg per week (P<0.01). More important were the changes on the cardiovascular functions: left ventricular mass at 116 (34) versus 134 (39) g/m(2) (P<0.02), left ventricular ejection fraction at 64.7 (4.4) versus 61.4 (8.7) % (P<0.02) and mean arterial pressure at 104.7 (80) versus 109 (13.2) mmHg (P<0.02). These Pts were also less hospitalized. This study revealed the importance of i.v. IT during predialysis care not only on AM but also on cardiovascular status in HD Pts starting dialysis.

Comparison of the safety and efficacy of 3 iron sucrose iron maintenance regimens in children, adolescents, and young adults with CKD: a randomized controlled trial

BACKGROUND

Iron deficiency is a common cause of anemia in young persons with chronic kidney disease (CKD). Iron repletion with intravenous (IV) iron formulations has been studied in children; maintenance IV iron regimens have not been reported extensively.

STUDY DESIGN

A multicenter randomized trial of IV iron sucrose.

SETTING & PARTICIPANTS

145 children, adolescents, and young adults with CKD receiving erythropoiesis-stimulating agent (ESA) therapy were stratified by dialysis category (hemodialysis, peritoneal dialysis, or non-dialysis dependent) and weight (<50 and ≥50 kg).

INTERVENTION

Patients were randomly assigned to 1 of 3 dosing arms: 0.5, 1.0, or 2.0 mg/kg (maximum single dose, 100 mg), stratified into hemodialysis versus nonhemodialysis (peritoneal dialysis or non-dialysis-dependent CKD) groups. Patients treated with hemodialysis received study medication once every other week for 6 doses. Patients in the nonhemodialysis group received study medication once every 4 weeks for 3 doses.

OUTCOMES

We assessed adverse event rates between dosing groups. The main clinical end point was a composite of hemoglobin level ≥10.5-14.0 g/dL, inclusive; transferrin saturation ≥20%-50%, inclusive; and stable ESA dosing (±25% of baseline dose).

RESULTS

Between-group difference for composite clinical end point rate attainment was -3.9% (95% CI, -21.4% to 13.7%) for the 1.0-mg/kg group versus 0.5-mg/kg group, +3.9% (95% CI, -15.1% to 23.0%) for the 2-mg/kg group versus 0.5-mg/kg group, and +7.8% (95% CI, -10.9% to 26.5%) for the 2-mg/kg group versus 1-mg/kg group. No differences were noted between regimens in reported adverse effects, which were all minor.

LIMITATIONS

Absence of a control group receiving no IV iron. Short duration of intervention and observation. A small proportion of patients having achieved the primary clinical outcome.

CONCLUSIONS

IV iron sucrose at a dose of 0.5 mg/kg at the intervals prescribed is noninferior to higher doses in maintaining hemoglobin levels >10.5 g/dL in children, adolescents, and young adults receiving ESA therapy.

Trends and variations in intravenous vitamin D use among hemodialysis patients in the United States

Injectable vitamin D agents are commonly used to manage secondary hyperparathyroidism in dialysis patients. Yet, there are few data documenting the trends and geographic variations in the use of these agents in large, representative samples. We sought to describe patterns and variations in the use of vitamin D formulations (calcitriol, paricalcitol, and doxercalciferol) in hemodialysis patients. We studied patients in the United States Renal Data System between January1999 and December 2008 with Medicare as a primary payer. Annual percentages of patients treated with each type of formulation were tabulated by race, sex, and age at dialysis initiation. The geographical distribution of vitamin D dose per patient was mapped at the state level. Intravenous vitamin D use has increased sharply from 1999 to 2008 with 83.9% of patients treated with any vitamin D formulation in 2008. The use of calcitriol has declined since 1999, going from being administered in 58.6% of patients in 1999 to 1.8% in 2008. Paricalcitol was found to be the overwhelmingly preferred formulation during the study years. In 2008, the average dose among black patients was 84% greater than among white patients (136 mcg vs. 73.6 mcg). Higher doses of vitamin D were administered to patients in the southern region of the country. Vitamin D use has increased and parallels the rise in use of paricalcitol and doxercalciferol. Given the variations in use and known pharmacologic differences in vitamin D formulations, future research should focus on whether the formulations differentially affect patient outcomes.

Changing patterns of anemia management in US hemodialysis patients

BACKGROUND

Erythropoiesis-stimulating agents and adjuvant intravenous iron have been the primary treatment for anemia in chronic kidney disease. Recent clinical and policy-related events have challenged this traditional paradigm, particularly in regard to erythropoiesis-stimulating agents. Less is known about the impact of these events on intravenous iron use.

METHODS

United States Renal Data System data (2002-2008) on Medicare hemodialysis patients were examined. For each patient, monthly intravenous iron dose, erythropoiesis-stimulating agent dose, and hemoglobin values were determined. Data were summarized by calendar quarter and plotted for the entire sample and by demographic, clinical, and facility-level subgroups. Marginal means for these variables also were computed to account for changes in patient characteristics over time.

RESULTS

Quarterly iron use increased from 64% in 2002 to 76% in 2008. Mean quarterly iron dose increased from 500 mg in 2002 to 650 mg in 2008. Mean monthly erythropoiesis-stimulating agent dose (per quarter) increased from 2002 to 2006 and then declined. Mean hemoglobin values followed a pattern similar to erythropoiesis-stimulating agent dose. The same patterns in iron, erythropoiesis-stimulating agent dose, and hemoglobin were generally observed across demographic, clinical, facility, and geographic subgroups, with some important differences between subgroups, specifically race and dialysis vintage.

CONCLUSIONS

Anemia management patterns have changed markedly between 2002 and 2008, with a steady increase in intravenous iron use even after declines in erythropoiesis-stimulating agent dose and hemoglobin. The clinical impacts of these changes need further evaluation.

Utilization Patterns of IV Iron and Erythropoiesis Stimulating Agents in Anemic Chronic Kidney Disease Patients: A Multihospital Study

Intravenous (IV) iron and Erythropoiesis Stimulating Agents (ESAs) are recommended for anemia management in chronic kidney disease (CKD). This retrospective cohort study analyzed utilization patterns of IV iron and ESA in patients over 18 years of age admitted to University Health System Hospitals with a primary or secondary diagnosis of CKD between January 1, 2006 to December 31, 2008. A clustered binomial logistic regression using the GEE methodology was used to identify predictors of IV iron utilization. Only 8% (n = 6678) of CKD patients on ESA therapy received IV iron supplementation in university hospitals. Those receiving iron used significantly less amounts of ESAs. Patient demographics (age, race, primary payer), patient clinical conditions (admission status, severity of illness, dialysis status), and physician specialty were identified as predictors of IV iron use in CKD patients. Use of IV iron with ESAs was low despite recommendations from consensus guidelines. The low treatment rate of IV iron represents a gap in treatment practices and signals an opportunity for healthcare improvement in CKD anemic patients.

Integrated Care of Anemia in Chronic Kidney Disease Patients: Concepts in Intravenous Iron Management: Part One

Chronic kidney disease (CKD) has become a worldwide public health issue with increasing prevalence in the United States. As kidney function declines, anemia or other complications may arise, and hemodialysis (HD) or kidney transplantation may be needed. Early intervention and treatment of CKD complications will improve clinical outcomes and may delay or prevent disease sequelae. Primary or adjuvant iron replacement in CKD patients with anemia is recommended. The National Kidney Foundation guidelines state that patients receiving erythropoiesis-stimulating agent (ESA) therapy and HD will require intravenous (IV) iron for optimal iron stores and ESA efficacy. This article, the first of a two-part series, details the optimization of IV iron therapy in CKD patients, clinical trial evaluation of IV versus oral iron in the non–HD-dependent CKD patient, and a comparison of the four available IV iron agents. The percent changes in ESA utilization in conjunction with iron therapy and the associated cost savings are also addressed. The second article in this series goes on to describe elements of the medication use process for care of CKD patients with anemia.

The impact of NSF on the care of patients with kidney disease

The association of nephrogenic systemic fibrosis (NSF) with the use of gadolinium-based magnetic resonance contrast agents (GBMCAs) has greatly affected the care of patients with kidney disease. Nephrogenic systemic fibrosis has been reported in patients with end-stage renal disease, chronic kidney disease (CKD) and acute kidney injury. The majority of cases have occurred in patients with end-stage renal disease, but cases of NSF have been reported in CKD patients with glomerular filtration rates less than 30 mL/min/1.73 m(2). Odds ratios have ranged between 8.97 and 32.5 among patients exposed to GBMCAs. Given the significant morbidity, disability, and mortality associated with NSF, it is imperative to properly and preemptively identify those patients at risk. Patients with end-stage renal disease seem to be at highest risk, particularly those maintained on peritoneal dialysis (PD). Although there are no data to support a role for hemodialysis in reducing the risk for NSF after the administration of GBMCAs, hemodialysis is recommended within 2 to 3 hours. Patients maintained on PD and those with CKD present a challenge, as they do not typically have vascular access for hemodialysis, yet the clearance of GBMCAs is very low, and it may be prudent to consider hemodialysis especially for PD patients. Gadolinium-based magnetic resonance contrast agents are removed by dialysis, with estimates that about 99% of a dose is removed after 3 to 4 sessions of hemodialysis. The elimination half-life averaged 9 hours in patients with stage 4 CKD (glomerular filtration rate <30 mL/min/1.73 m(2)) compared with 1.5 hours in those with normal glomerular filtration rates. This prolonged elimination and longer exposure may be important factors in predisposing to NSF.

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.

Intravenous versus Oral Iron Supplementation in Peritoneal Dialysis Patients

Iron supplementation is required in a preponderance of peritoneal dialysis (PD) patients treated with erythropoietic stimulatory agents (ESAs). Although many authors and clinical practice guidelines recommend primary oral iron supplementation in ESA-treated PD patients, numerous studies have clearly demonstrated that, because of a combination of poor bioavailability of oral iron, gastrointestinal intolerance, and noncompliance, oral iron supplementation is insufficient for maintaining a positive iron balance in these patients over time. Controlled trials have demonstrated that, in iron-deficient and iron-replete PD patients alike, intravenous (IV) iron supplementation results in superior iron stores and hemoglobin levels with fewer side effects than oral iron produces. Careful monitoring of iron stores in patients receiving IV iron supplementation is important in view of conflicting epidemiologic links between IV iron loading and infection and cardiovascular disease. Emerging new iron therapies such as heme iron polypeptide and ferumoxytol may further enhance the tolerability, efficacy, and ease of administration of iron in PD patients.

Comparison of Oxidative Stress Markers After Intravenous Administration of Iron Dextran, Sodium Ferric Gluconate, and Iron Sucrose in Patients Undergoing Hemodialysis

STUDY OBJECTIVE

To compare non-transferrin-bound iron and markers of oxidative stress after single intravenous doses of iron dextran, sodium ferric gluconate, and iron sucrose.

DESIGN

Prospective, open-label, crossover study.

SETTING

University-affiliated general clinical research center.

PATIENTS

Twelve ambulatory patients undergoing hemodialysis.

INTERVENTION

Patients received 100 mg of intravenous iron dextran, sodium ferric gluconate, and iron sucrose in random sequence, with a 2-week washout period between treatments.

MEASUREMENTS AND MAIN RESULTS

Serum samples for transferrin saturation, non-transferrin-bound iron, and malondialdehyde (MDA; marker of lipid peroxidation) were obtained before (baseline) and 30, 60, 120, and 360 minutes and 2 weeks after each iron infusion. A serum sample for hemeoxygenase-1 (HO-1) RNA was obtained at baseline and 360 minutes after infusion. Non-transferrin-bound iron values were significantly higher 30 minutes after administration of sodium ferric gluconate and iron sucrose compared with iron dextran (mean +/- SEM 10.1 +/- 2.2, 3.8 +/- 0.8, and 0.23 +/-0.1 microM, respectively, p<0.001 for sodium ferric gluconate vs iron dextran, p = 0.002 for iron sucrose vs iron dextran). A significant positive correlation was noted between transferrin saturation and the presence of non-transferrin-bound iron for sodium ferric gluconate and iron sucrose (r2 = 0.37 and 0.45, respectively, p<0.001) but not for iron dextran (r2 = 0.09). After sodium ferric gluconate, significantly more samples showed increases in MDA levels from baseline compared with iron sucrose and iron dextran (p = 0.006); these increased levels were associated with the presence of non-transferrin-bound iron, baseline transferrin saturation above 30%, baseline transferrin levels below 180 mg/dl, and ferritin levels above 500 ng/ml (p<0.05). However, only a transferrin level below 180 mg/dl was independently associated (odds ratio 4.8, 95% confidence interval 1.2-15.3).

CONCLUSION

Iron sucrose and sodium ferric gluconate were associated with greater non-transferrin-bound iron appearance compared with iron dextran. However, only sodium ferric gluconate showed significant increases in lipid peroxidation. The relationship between non-transferrin-bound iron from intravenous iron and oxidative stress warrants further exploration.

Iron therapy for renal anemia: how much needed, how much harmful?

Iron deficiency is the most common cause of hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) in end-stage renal disease (ESRD) patients. Iron deficiency can easily be corrected by intravenous iron administration, which is more effective than oral iron supplementation, at least in adult patients with chronic kidney disease (CKD). Iron status can be monitored by different parameters such as ferritin, transferrin saturation, percentage of hypochromic red blood cells, and/or the reticulocyte hemoglobin content, but an increased erythropoietic response to iron supplementation is the most widely accepted reference standard of iron-deficient erythropoiesis. Parenteral iron therapy is not without acute and chronic adverse events. While provocative animal and in vitro studies suggest induction of inflammation, oxidative stress, and kidney damage by available parenteral iron preparations, several recent clinical studies showed the opposite effects as long as intravenous iron was adequately dosed. Thus, within the recommended international guidelines, parenteral iron administration is safe. Intravenous iron therapy should be withheld during acute infection but not during inflammation. The integration of ESA and intravenous iron therapy into anemia management allowed attainment of target hemoglobin values in the majority of pediatric and adult CKD and ESRD patients.

The effect of intravenous iron on oxidative stress in hemodialysis patients at various levels of vitamin C

BACKGROUND/AIMS

Vitamin C levels decrease during hemodialysis (HD), which deteriorates antioxidant defense. Vitamin C may also act pro-oxidatively, via reduction in Fe(III). We sought to determine whether intravenous iron (Fe(iv))-induced oxidative stress differs in HD patients with low and physiological vitamin C levels and whether intravenous vitamin C (C(iv)) administration during HD would change the response to Fe(iv).

PATIENTS AND METHODS

Twenty patients with vitamin C deficiency (median 15.7 micromol/l, range 8.0-22.7) received Fe(iv) (100 mg iron sucrose between 150 and 180 min of HD). After 4 weeks of oral supplementation, the levels of vitamin C were comparable with those of controls (60.1 micromol/l, range 47.4-70.9). Patients were subsequently treated with (1) Fe(iv), (2) Fe(iv) and continuous 2 mg/min C(iv) throughout HD, (3) saline (S), and (4) S+C(iv). Plasma thiobarbituric acid reacting substances (TBARS) and vitamin C were assessed before, during and after FE(iv)(S), and 15, 30 and 60 min after infusion.

RESULTS

Fe(iv) induced a comparable rise in TBARS in patients with vitamin C deficiency (before Fe(iv), 1.9 micromol/l, range 1.4-1.9; after Fe(iv), 2.6 micromol/l, range 2.3-2.9; p < 0.01) and in those with normal vitamin C (before Fe(iv), 1.9 micromol/l, range 1.7-2.1; after Fe(iv), 2.6 micromol/l, range 2.5-2.9; p < 0.01). Fe(iv)+C(iv) resulted in a greater increase in TBARS (after Fe(iv), 3.1 micromol/l, range 2.8-3.2) compared with Fe(iv) (p < 0.01).

CONCLUSION

Iron sucrose-induced oxidative stress is comparable in HD patients with vitamin C deficiency and in those with normal vitamin C. We documented a pro-oxidative effect of vitamin C during Fe(iv)+C(iv) administration.

Resolving the paradigm crisis in intravenous iron and erythropoietin management

Despite the proven benefits of intravenous (i.v.) iron therapy in anemia management, it remains underutilized in the hemodialysis population. Although overall i.v. iron usage continues to increase slowly, monthly usage statistics compiled by the US Renal Data System suggest that clinicians are not implementing continued dosing regimens following repletion of iron stores. Continued therapy with i.v. iron represents a key opportunity to improve patient outcomes and increase the efficiency of anemia treatment. Regular administration of low doses of i.v. iron prevents the recurrence of iron deficiency, enhances response to recombinant human erythropoietin therapy, minimizes fluctuation of hemoglobin levels, hematocrit levels, and iron stores, and may reduce overall costs of care. This article reviews the importance of i.v. iron dosing on a regular basis in the hemodialysis patient with iron-deficiency anemia and explores reasons why some clinicians may still be reluctant to employ these protocols in the hemodialysis setting.