The comparative safety of intravenous iron dextran, iron saccharate, and sodium ferric gluconate

Intravenous ferric derisomaltose for the treatment of iron deficiency anemia

Intravenous (IV) iron is the therapy of choice when oral iron is ineffective or poorly tolerated, yet use has been limited by fears of hypersensitivity reactions (HSRs). Newer formulations that bind iron more tightly and release it more slowly have made the risk of serious or severe HSRs very low. One such formulation, ferric derisomaltose, has been approved in the United States for delivery of 1000 mg iron in a single IV infusion. Ferric derisomaltose rapidly repletes iron parameters with low rates of serious or severe HSRs. Single-infusion iron repletion offers convenience, eliminates adherence concerns, and reduces healthcare resource utilization.

Intravenous Iron Sucrose in Peritoneal Dialysis Patients with Renal Anemia

Objective

To explore the safety and efficacy of intravenous (IV) iron sucrose in maintenance peritoneal dialysis (PD).

Design

Randomized, controlled, parallel-group single-center trial.

Setting

Blood Purification Center of Chaoyang, Beijing Capital University of Medical Science, China.

Methods

46 patients on PD were involved in this trial. 26 patients received IV iron sucrose (200 mg iron) once per week for 4 weeks then once every other week for a further 4 weeks. The other 20 patients received oral ferrous succinate, 200 mg three times per day, for 8 weeks. Hemoglobin, hematocrit, serum ferritin (SF) level, and transferrin saturation (TSAT) were assessed at baseline and then again after 2, 4, and 8 weeks of treatment.

Results

There were no differences between the IV and oral groups in terms of sex, age, duration of PD, mean dialysate dosage per day, erythropoietin dosage per week, or hematological parameters at baseline. After 4 and 8 weeks of treatment, mean Hb and Hct were significantly increased in the IV group and were also significantly higher than those in the oral group. Levels of SF and TSAT were also significantly increased in the IV group, and significantly higher than in the oral group. After 8 weeks, the response rate in the IV group was 94.8%, which was significantly higher than that in the oral group. The mean erythropoietin dose was significantly lower in the IV group than in the oral group. Hb, Hct, SF, and TSAT levels were maintained between 4 and 8 weeks in the IV group despite the decrease in dose frequency. There were no adverse events with IV iron. Eight patients in the oral group had adverse gastrointestinal effects.

Conclusion

IV iron sucrose is safe in PD patients. It increases Hb levels and serum iron parameters more effectively than oral iron; it is well tolerated and can permit reductions in the required dose of erythropoietin.

Micronutrients Dietary Supplementation Advices for Celiac Patients on Long-Term Gluten-Free Diet with Good Compliance: A Review

Background and objective: Often micronutrient deficiencies cannot be detected when patient is already following a long-term gluten-free diet with good compliance (LTGFDWGC). The aim of this narrative review is to evaluate the most recent literature that considers blood micronutrient deficiencies in LTGFDWGC subjects, in order to prepare dietary supplementation advice (DSA). Materials and methods: A research strategy was planned on PubMed by defining the following keywords: celiac disease, vitamin B12, iron, folic acid, and vitamin D. Results: This review included 73 studies. The few studies on micronutrient circulating levels in long-term gluten-free diet (LTGFD) patients over 2 years with good compliance demonstrated that deficiency was detected in up to: 30% of subjects for vitamin B12 (DSA: 1000 mcg/day until level is normal, then 500 mcg), 40% for iron (325 mg/day), 20% for folic acid (1 mg/day for 3 months, followed by 400–800 mcg/day), 25% for vitamin D (1000 UI/day or more-based serum level or 50,000 UI/week if level is <20 ng/mL), 40% for zinc (25–40 mg/day), 3.6% of children for calcium (1000–1500 mg/day), 20% for magnesium (200–300 mg/day); no data is available in adults for magnesium. Conclusions: If integration with diet is not enough, starting with supplements may be the correct way, after evaluating the initial blood level to determine the right dosage of supplementation.

Pathogenesis and Treatment Options of Cancer Related Anemia: Perspective for a Targeted Mechanism-Based Approach

Cancer-related anemia (CRA) is a common sign occurring in more than 30% of cancer patients at diagnosis before the initiation of antineoplastic therapy. CRA has a relevant influence on survival, disease progression, treatment efficacy, and the patients' quality of life. It is more often detected in patients with advanced stage disease, where it represents a specific symptom of the neoplastic disease, as a consequence of chronic inflammation. In fact, CRA is characterized by biological and hematologic features that resemble those described in anemia associated to chronic inflammatory disease. Proinflammatory cytokine, mainly IL-6, which are released by both tumor and immune cells, play a pivotal action in CRA etiopathogenesis: they promote alterations in erythroid progenitor proliferation, erythropoietin (EPO) production, survival of circulating erythrocytes, iron balance, redox status, and energy metabolism, all of which can lead to anemia. The discovery of hepcidin allowed a greater knowledge of the relationships between immune cells, iron metabolism, and anemia in chronic inflammatory diseases. Additionally, chronic inflammation influences a compromised nutritional status, which in turn might induce or contribute to CRA. In the present review we examine the multifactorial pathogenesis of CRA discussing the main and novel mechanisms by which immune, nutritional, and metabolic components affect its onset and severity. Moreover, we analyze the status of the art and the perspective for the treatment of CRA. Notably, despite the high incidence and clinical relevance of CRA, controlled clinical studies testing the most appropriate treatment for CRA are scarce, and its management in clinical practice remains challenging. The present review may be useful to indicate the development of an effective approach based on a detailed assessment of all factors potentially involved in the pathogenesis of CRA. This mechanism-based approach is essential for clinicians to plan a safe, targeted, and successful therapy, thereby promoting a relevant amelioration of patients' quality of life.

Role of iron metabolism in heart failure: From iron deficiency to iron overload

Iron metabolism is a balancing act, and biological systems have evolved exquisite regulatory mechanisms to maintain iron homeostasis. Iron metabolism disorders are widespread health problems on a global scale and range from iron deficiency to iron-overload. Both types of iron disorders are linked to heart failure. Iron play a fundamental role in mitochondrial function and various enzyme functions and iron deficiency has a particular negative impact on mitochondria function. Given the high-energy demand of the heart, iron deficiency has a particularly negative impact on heart function and exacerbates heart failure. Iron-overload can result from excessive gut absorption of iron or frequent use of blood transfusions and is typically seen in patients with congenital anemias, sickle cell anemia and beta-thalassemia major, or in patients with primary hemochromatosis. This review provides an overview of normal iron metabolism, mechanisms underlying development of iron disorders in relation to heart failure, including iron-overload cardiomyopathy, and clinical perspective on the treatment options for iron metabolism disorders.

Pharmaceutical stability of colloidal saccharated iron oxide injection in normal saline

Background

Colloidal saccharated iron oxide injection is used for the treatment of iron deficiency anemia in patients with a poor oral intake. Because of the poor stability of the colloid particle, there have been concerns regarding its compatibility with various injections in clinical practice. To assess the stability of colloidal saccharated iron oxide in normal saline as a diluent, pharmaceutical stability analyses were conducted using various concentrations of glucose and sodium chloride (NaCl).

Methods

Colloidal saccharated iron oxide injection was diluted in three different diluents (5% glucose solution, normal saline, and 10% NaCl solution), and its appearance, colloid particle diameter, and pH were assessed. Free iron ions, which cause adverse effects, such as nausea and vomiting, were separated from the colloid particle using a dialysis membrane for 24 h, and their concentration was determined.

Results

No difference in the appearance, colloid diameter, and free iron ion fraction was observed after dilution in 5% glucose solution and normal saline. Conversely, an increased colloid aggregation and iron ion release were observed after dilution in 10% NaCl solution. Although iron colloid is unstable in acidic conditions (pH 4.0-6.0), normal diluents such as 5% glucose and normal saline did not cause colloid destabilization by pH change (pH > 8.0).

Conclusion

Normal saline may be used as a diluent of colloidal saccharated iron oxide injection as well as glucose solution, which is recommended by the pharmaceutical company. Therefore, normal saline can be used as a diluent of colloidal saccharated iron oxide injection in patients with an underlying disease, such as diabetes mellitus, who are difficult to use glucose solution as a diluent.

Utilization trends and safety of intravenous iron replacement in pediatric specialty care: A large retrospective cohort study

BACKGROUND

Iron deficiency is a common and clinically diverse hematologic disorder in childhood for which oral iron is often an infeasible or ineffective treatment option. Intravenous (IV) iron can be an efficient and highly successful means of iron replacement but its use has not been well-characterized on a large scale in pediatrics.

PROCEDURE

All IV iron doses administered to patients for iron replacement therapy at a tertiary pediatric hospital from January 2010 through October 2016 were evaluated. Analyses included patient demographics, underlying medical conditions, and detailed information for each dose. Individual chart review was performed to identify infusion-related reactions. Nephrology patients as well as those patients 21 years or older at the time of the first infusion were excluded.

RESULTS

A total of 1,088 doses of IV iron administered to 194 patients met inclusion criteria. A wide variety of specialties prescribed IV iron, with gastroenterology, hematology, and hospital medicine being the highest users in this cohort. A majority of patients (68%) required multiple infusions and dosing was highly variable, ranging from 1.3-1,030 mg per infusion. Premedication use was infrequent (10.3% of doses) and no severe infusion-associated reactions occurred.

CONCLUSIONS

IV iron is commonly prescribed by certain pediatric specialties but there is little standardization in the indications, formulations, or dosing. These data suggest that IV iron should be considered a safe alternative for iron deficiency treatment in pediatrics when oral iron is either unsuccessful or contraindicated.

Iron deficiency in chronic and acute heart failure: A contemporary review on intertwined conditions

Iron Deficiency (ID) is increasingly recognized as a prevalent comorbid condition in Heart Failure (HF). Despite this, the pathophysiological mechanisms for progressive ID in either chronic or acute HF are still poorly understood. Beyond the traditional factors for iron deficit in the general population, we ought to review the specificities of such paucity in the HF patient, particularly focusing on the interplay between heightened inflammation, overactivity of the sympathetic nervous system and the so-called cardio-renal-anaemia-ID syndrome. Currently, ID constitutes not only an independent prognostic marker but also a novel safe therapeutic target. Particularly, in selected stable HF patients with reduced left ventricular ejection fraction, intravenous (IV) iron improves symptomatic burden and reduces hospitalizations due to worsening HF. On this topic, the main trials of IV iron with either iron sucrose (Toblli et al., FERRIC-HF and IRON-HF) or ferric carboxymaltose (FAIR-HF, CONFIRM-HF and EFFECT-HF) will be summarized and discussed. Finally, we debate the gaps in knowledge of ID in special populations, namely the unreliability of routine plasmatic surrogate markers to assess iron status in acute and advanced HF, the challenging patient with both HF and Chronic Kidney Disease, as well as efficacy and safety concerns in these settings and the potential role of iron correction in cardiac resynchronization therapy candidates.

Nanomedicine: is it lost in translation?

By the end of 2017 more than 200,000 scientific research articles had been published about nanomedicine. Out of this vast number only a few of the reported nanoconstructs reached clinical trials for various applications, including the diagnosis and treatment of several cancers, and the treatment of infections and other non-cancerous diseases. 30 years after the pioneering work in this field of research, the low product yield at the end of research pipeline leads to a question that is asked by many: 'had nanomedicine been lost in translation?' In this review, we will discuss the landscape of nanomedicine regarding cancer treatment and miscellaneous applications as well as some obstacles toward full utilization of this powerful therapeutic tool and suggest a few solutions to improve the current translational value of nanomedicine research.

Plasma vitamin C levels in ESRD patients and occurrence of hypochromic erythrocytes

INTRODUCTION

The achievement of erythropoiesis in hemodialysis (HD) patients is typically managed with erythropoiesis-stimulating-agents (ESA's) and intravenous iron (IV-iron). Using this treatment strategy, HD patients frequently show an elevated fraction of red blood cells (RBC) with hemoglobin (Hb) content per cell that is below the normal range, called hypochromic RBC. The low Hb content per RBC is the result of the clinical challenge of providing sufficient iron content to the bone marrow during erythropoiesis. Vitamin C supplements have been used to increase Hb levels in HD patients with refractory anemia, which supports the hypothesis that vitamin C mobilizes iron needed for Hb synthesis.

METHODS

We conducted a cross-sectional survey in 149 prevalent HD patients of the percent hypochromic RBC, defined as RBC with Hb < 300 ng/uL of packed RBC, in relation to plasma vitamin C levels. We also measured high-sensitivity CRP, (hs-CRP), iron, and ferritin levels. and calculated ESA dose.

FINDINGS

High plasma levels of vitamin C were negatively associated with hypochromic RBC (P < 0.003), and high ESA doses were positively associated (P < 0.001). There was no significant association of hs-CRP with percent hypochromic RBC.

DISCUSSION

This finding supports the hypothesis that vitamin C mobilizes iron stores, improves iron delivery to the bone marrow, and increase the fraction of RBC with normal Hb content. Further research is warranted on development of protocols for safe and effective use of supplemental vitamin C for management of renal anemia.

Effect of Intravenous Iron Supplementation on Acute Mountain Sickness: A Preliminary Randomized Controlled Study

BACKGROUND

The aim of this study was to assess the role of intravenous iron supplementation in the prevention of AMS.

MATERIAL AND METHODS

This was a randomized, double-blinded, placebo-controlled study. Forty-one (n=41) healthy Chinese low-altitude inhabitants living in Beijing, China (altitude of about 50 meters) were randomly assigned into intravenous iron supplementation (ISS group; n=21) and placebo (CON group; n=20) groups. Participants in the ISS group received iron sucrose supplement (200 mg) before flying to Lhasa, China (altitude of 4300 meters). Acute mountain sickness (AMS) severity was assessed with the Lake Louise scoring (LLS) system within 5 days after landing on the plateau (at high altitude). Routine check-ups, clinical biochemistry, and blood tests were performed before departure and 24 h after arrival.

RESULTS

A total of 38 participants completed the study (ISS group: n=19; CON group: n=19). The rate of subjects with AMS (LLS>3) was lower in the ISS group compared with the CON group, but no significant differences were obtained (P>0.05). There were no differences in patients' baseline characteristics. The physiological indices were similar in both groups except for serum iron concentrations (19.44±10.02 vs. 85.10±26.78 μmol/L) and transferrin saturation rates (28.20±12.14 vs. 68.34±33.12%), which were significantly higher in the ISS group (P<0.05). Finally, heart rate was identified as a contributing factor of LLS.

CONCLUSIONS

These preliminary findings suggest that intravenous iron supplementation has no significant protective effect on AMS in healthy Chinese low-altitude inhabitants.

A multicenter, randomized clinical trial of IV iron supplementation for anemia of traumatic critical illness*

OBJECTIVE

To evaluate the efficacy of IV iron supplementation of anemic, critically ill trauma patients.

DESIGN

Multicenter, randomized, single-blind, placebo-controlled trial.

SETTING

Four trauma ICUs.

PATIENTS

Anemic (hemoglobin < 12 g/dL) trauma patients enrolled within 72 hours of ICU admission and with an expected ICU length of stay of more than or equal to 5 days.

INTERVENTIONS

Randomization to iron sucrose 100 mg IV or placebo thrice weekly for up to 2 weeks.

MEASUREMENTS AND MAIN RESULTS

A total of 150 patients were enrolled. Baseline iron markers were consistent with functional iron deficiency: 134 patients (89.3%) were hypoferremic, 51 (34.0%) were hyperferritinemic, and 64 (42.7%) demonstrated iron-deficient erythropoiesis as evidenced by an elevated erythrocyte zinc protoporphyrin concentration. The median baseline transferrin saturation was 8% (range, 2-58%). In the subgroup of patients who received all six doses of study drug (n = 57), the serum ferritin concentration increased significantly for the iron as compared with placebo group on both day 7 (808.0 ng/mL vs 457.0 ng/mL, respectively, p < 0.01) and day 14 (1,046.0 ng/mL vs 551.5 ng/mL, respectively, p < 0.01). There was no significant difference between groups in transferrin saturation, erythrocyte zinc protoporphyrin concentration, hemoglobin concentration, or packed RBC transfusion requirement. There was no significant difference between groups in the risk of infection, length of stay, or mortality.

CONCLUSIONS

Iron supplementation increased the serum ferritin concentration significantly, but it had no discernible effect on transferrin saturation, iron-deficient erythropoiesis, hemoglobin concentration, or packed RBC transfusion requirement. Based on these data, routine IV iron supplementation of anemic, critically ill trauma patients cannot be recommended (NCT 01180894).

Iron deficiency in heart failure: a practical guide

Iron is an element necessary for cells due to its capacity of transporting oxygen and electrons. One of the important co-morbidities in heart failure is iron deficiency. Iron has relevant biological functions, for example, the formation of haemoglobin, myoglobin and numerous enzymatic groups. The prevalence of iron deficiency increases with the severity of heart failure. For a long time, the influence of iron deficiency was underestimated especially in terms of worsening of cardiovascular diseases and of developing anaemia. In recent years, studies with intravenous iron agents in patients with iron deficiency and cardiovascular diseases indicated new insights in the improvement of therapy. Experimental studies support the understanding of iron metabolism. Many physicians remain doubtful of the use of intravenous iron due to reports of side effects. The aim of this review is to describe iron metabolism in humans, to highlight the influence of iron deficiency on the course and symptoms of heart failure, discuss diagnostic tools of iron deficiency and provide guidance on the use of intravenous iron.

Efficacy and safety of intravenous iron sucrose in treating adults with iron deficiency anemia

Background

Iron deficiency is the most common disorder in the world, affecting approximately 25% of the world`s population and the most common cause of anemia.

Objective

To evaluate the efficacy and safety of intravenous iron sucrose (IS) in the treatment of adults with iron deficiency anemia

Methods

Eighty-six adult patients with iron deficiency anemia, who had intolerance or showed no effect with oral iron therapy, received a weekly dose of 200 mg of intravenous iron sucrose until the hemoglobin level was corrected or until receiving the total dose of intravenous iron calculated for each patient

Results

The mean hemoglobin and serum ferritin levels were 8.54 g/dL and 7.63 ng/mL (pre-treatment) and 12.1 g/dL and 99.0 ng/mL (post-treatment) (p-value < 0.0001), respectively. The average increases in hemoglobin levels were 3.29 g/dL for women and 4.58 g/dL for men; 94% of male and 84% of female patients responded (hemoglobin increased by at least 2 g/dL) to intravenous iron therapy. Correction of anemia was obtained in 47 of 69 (68.1%) female patients and in 12 of 17 male (70.6%) patients. A total of 515 intravenous infusions of iron sucrose were administered and iron sucrose was generally well tolerated with no moderate or serious adverse drug reactions recorded by the investigators.

Conclusions

Our data confirm that the use of intravenous iron sucrose is a safe and effective option in the treatment of adult patients with iron deficiency anemia who lack satisfactory response to oral iron therapy. Intravenous iron sucrose is well tolerated and with a clinically manageable safety profile when using appropriate dosing and monitoring. The availability of intravenous iron sucrose would potentially improve compliance and thereby reduce morbidities from iron deficiency.

Intravenous iron therapy: how far have we come?

Oral iron supplementation is usually the first choice for the treatment of iron deficiency anemia (IDA) because of its effectiveness and low cost. But unfortunately in many iron deficient conditions, oral iron is a less than the ideal treatment mainly because of adverse events related to the gastrointestinal tract as well as the long course required to treat anemia and replenish body iron stores. The first iron product for intravenous use was high-molecular-weight iron dextran. However, dextran-containing intravenous iron preparations are associated with an elevated risk of anaphylactic reactions, which made physicians reluctant to prescribe intravenous iron in the treatment of iron deficiency anemia for many years. In 1999 and 2001, two new intravenous iron preparations (ferric gluconate and iron sucrose) were introduced into the market as safer alternatives to iron dextran. Over the last five years, three new intravenous iron dextran-free preparations have been developed and have better safety profiles than the more traditional intravenous compounds, as none require test doses and all these products are promising in respect to a more rapid replacement of body iron stores (15-60 minutes/infusion) as they can be given at higher doses (from 500 mg to more than 1000 mg/infusion). The purpose of this review is to discuss some pertinent issues in relation to the history, pharmacology, administration, efficacy, safety profile and toxicity of intravenous iron for the treatment of iron deficiency anemia.

Understanding renal posttransplantation anemia in the pediatric population

Advances in renal transplantation management have proven to be beneficial in improving graft and patient survival. One of the properties of a well-functioning renal allograft is the secretion of adequate amounts of the hormone erythropoietin to stimulate erythropoiesis. Posttransplantation anemia (PTA) may occur at any point in time following transplantation, and the cause is multifactoral. Much of our understanding of PTA is based on studies of adult transplant recipients. The limited number of studies that have been reported on pediatric renal transplant patients appear to indicate that PTA is prevalent in this patient population. Erythropoietin deficiency or resistance is commonly associated with iron deficiency. An understanding of the risk factors, pathophysiology and management of PTA in the pediatric renal transplant population may provide guidelines for clinicians and researchers in the pursuit of larger prospective randomized control studies aimed at improving our limited knowledge of PTA. Recognition of PTA through regular screening and evaluation of the multiple factors that may contribute to its development are recommended after transplantation.

Iron deficiency anaemia in pregnancy and postpartum: pathophysiology and effect of oral versus intravenous iron therapy

Nutritional iron-deficiency anaemia (IDA) is the most common disorder in the world, affecting more than two billion people. The World Health Organization's global database on anaemia has estimated a prevalence of 14% based on a regression-based analysis. Recent data show that the prevalence of IDA in pregnant women in industrialized countries is 17.4% while the incidence of IDA in developing countries increases significantly up to 56%. Although oral iron supplementation is widely used for the treatment of IDA, not all patients respond adequately to oral iron therapy. This is due to several factors including the side effects of oral iron which lead to poor compliance and lack of efficacy. The side effects, predominantly gastrointestinal discomfort, occur in a large cohort of patients taking oral iron preparations. Previously, the use of intravenous iron had been associated with undesirable and sometimes serious side effects and therefore was underutilised. However, in recent years, new type II and III iron complexes have been developed, which offer better compliance and toleration as well as high efficacy with a good safety profile. In summary, intravenous iron can be used safely for a rapid repletion of iron stores and correction of anaemia during and after pregnancy.

Comparative efficacy of three forms of parenteral iron

Intravenous iron therapy is a useful treatment for the rapid correction of iron deficiency anaemia and can be used to avoid or reduce the requirement for allogeneic blood transfusion. Several intravenous iron preparations are available commercially which differ in cost, mode of administration and side effect profile. There are few data directly comparing the efficacy of these preparations. In this retrospective single-centre study, we present the results from two hundred and eight patients treated using three different iron preparations (iron dextran, iron sucrose and ferric carboxymaltose) and compare the effect on haemoglobin levels and other measures of iron deficiency six weeks after treatment. Within the limitations of our study design, we show a statistically and clinically significant difference in efficacy between these preparations.

Optimal management of iron deficiency anemia due to poor dietary intake

Iron is necessary for the normal development of multiple vital processes. Iron deficiency (ID) may be caused by several diseases, even by physiological situations that increase requirements for this mineral. One of its possible causes is a poor dietary iron intake, which is infrequent in developed countries, but quite common in developing areas. In these countries, dietary ID is highly prevalent and comprises a real public health problem and a challenge for health authorities. ID, with or without anemia, can cause important symptoms that are not only physical, but can also include a decreased intellectual performance. All this, together with a high prevalence, can even have negative implications for a community’s economic and social development. Treatment consists of iron supplements. Prevention of ID obviously lies in increasing the dietary intake of iron, which can be difficult in developing countries. In these regions, foods with greater iron content are scarce, and attempts are made to compensate this by fortifying staple foods with iron. The effectiveness of this strategy is endorsed by multiple studies. On the other hand, in developed countries, ID with or without anemia is nearly always associated with diseases that trigger a negative balance between iron absorption and loss. Its management will be based on the treatment of underlying diseases, as well as on oral iron supplements, although these latter are limited by their tolerance and low potency, which on occasions may compel a change to intravenous administration. Iron deficiency has a series of peculiarities in pediatric patients, in the elderly, in pregnant women, and in patients with dietary restrictions, such as celiac disease.

Parenteral Iron Therapy in the Pediatric Patient

For more than 50 years, iron dextran has been the mainstay of parenteral iron therapy in the United States. In October 2009, the Food and Drug Administration expanded its existing black box warning that cautioned practitioners to administer a test dose first because of the risk of anaphylactic, often fatal adverse reactions. It further modified the warning, stating that fatal reactions can still occur even in patients who tolerated the test dose. As a result, health care providers have sought safer alternatives to parenteral iron dextran when oral iron repletion is not an option. The purpose of this review is to discuss the currently available formulations, with a focus on the needs of the pediatric patient, in whom there is limited experience in using products other than iron dextran.

A comparative study of the physicochemical properties of iron isomaltoside 1000 (Monofer), a new intravenous iron preparation and its clinical implications

The treatment of iron deficiency anemia with polynuclear iron formulations is an established therapy in patients with chronic kidney disease but also in other disease areas like gastroenterology, cardiology, oncology, pre/post operatively and obstetrics' and gynecology. Parenteral iron formulations represent colloidal systems in the lower nanometer size range which have traditionally been shown to consist of an iron core surrounded by a carbohydrate shell. In this publication, we for the first time describe the novel matrix structure of iron isomaltoside 1000 which differs from the traditional picture of an iron core surrounded by a carbohydrate. Despite some structural similarities between the different iron formulations, the products differ significantly in their physicochemical properties such as particle size, zeta potential, free and labile iron content, and release of iron in serum. This study compares the physiochemical properties of iron isomaltoside 1000 (Monofer) with the currently available intravenous iron preparations and relates them to their biopharmaceutical properties and their approved clinical applications. The investigated products encompass low molecular weight iron dextran (CosmoFer), sodium ferric gluconate (Ferrlecit), iron sucrose (Venofer), iron carboxymaltose (Ferinject/Injectafer), and ferumoxytol (Feraheme) which are compared to iron isomaltoside 1000 (Monofer). It is shown that significant and clinically relevant differences exist between sodium ferric gluconate and iron sucrose as labile iron formulations and iron dextran, iron carboxymaltose, ferumoxytol, and iron isomaltoside 1000 as stable polynuclear formulations. The differences exist in terms of their immunogenic potential, safety, and convenience of use, the latter being expressed by the opportunity for high single-dose administration and short infusion times. Monofer is a new parenteral iron product with a very low immunogenic potential and a very low content of labile and free iron. This enables Monofer, as the only IV iron formulation, to be administered as a rapid high dose infusion in doses exceeding 1000 mg without the application of a test dose. This offers considerable dose flexibility, including the possibility of providing full iron repletion in a single infusion (one-dose iron repletion).

Disorders of iron metabolism. Part II: iron deficiency and iron overload

Main disorders of iron metabolism

Increased iron requirements, limited external supply, and increased blood loss may lead to iron deficiency (ID) and iron deficiency anaemia. In chronic inflammation, the excess of hepcidin decreases iron absorption and prevents iron recycling, resulting in hypoferraemia and iron restricted erythropoiesis, despite normal iron stores (functional iron deficiency), and finally anaemia of chronic disease (ACD), which can evolve to ACD plus true ID (ACD+ID). In contrast, low hepcidin expression may lead to hereditary haemochromatosis (HH type I, mutations of the HFE gene) and type II (mutations of the hemojuvelin and hepcidin genes). Mutations of transferrin receptor 2 lead to HH type III, whereas those of the ferroportin gene lead to HH type IV. All these syndromes are characterised by iron overload. As transferrin becomes saturated in iron overload states, non-transferrin bound iron appears. Part of this iron is highly reactive (labile plasma iron), inducing free radical formation. Free radicals are responsible for the parenchymal cell injury associated with iron overload syndromes.

Role of laboratory testing in diagnosis

In iron deficiency status, laboratory tests may provide evidence of iron depletion in the body or reflect iron deficient red cell production. Increased transferrin saturation and/or ferritin levels are the main cues for further investigation of iron overload. The appropriate combination of different laboratory tests with an integrated algorithm will help to establish a correct diagnosis of iron overload, iron deficiency and anaemia.

Review of treatment options

Indications, advantages and side effects of the different options for treating iron overload (phlebotomy and iron chelators) and iron deficiency (oral or intravenous iron formulations) will be discussed.

Intravenous iron in inflammatory bowel disease

The prevalence of anemia across studies on patients with inflammatory bowel disease (IBD) is high (30%). Both iron deficiency (ID) and anemia of chronic disease contribute most to the development of anemia in IBD. The prevalence of ID is even higher (45%). Anemia and ID negatively impact the patient’s quality of life. Therefore, together with an adequate control of disease activity, iron replacement therapy should start as soon as anemia or ID is detected to attain a normal hemoglobin (Hb) and iron status. Many patients will respond to oral iron, but compliance may be poor, whereas intravenous (IV) compounds are safe, provide a faster Hb increase and iron store repletion, and presents a lower rate of treatment discontinuation. Absolute indications for IV iron treatment should include severe anemia, intolerance or inappropriate response to oral iron, severe intestinal disease activity, or use of an erythropoietic stimulating agent. Four different products are principally used in clinical practice, which differ in their pharmacokinetic properties and safety profiles: iron gluconate and iron sucrose (lower single doses), and iron dextran and ferric carboxymaltose (higher single doses). After the initial resolution of anemia and the repletion of iron stores, the patient’s hematological and iron parameters should be carefully and periodically monitored, and maintenance iron treatment should be provided as required. New IV preparations that allow for giving 1000-1500 mg in a single session, thus facilitating patient management, provide an excellent tool to prevent or treat anemia and ID in this patient population, which in turn avoids allogeneic blood transfusion and improves their quality of life.

The comparative safety of various intravenous iron preparations in chronic kidney disease patients

The relative safety of parenteral iron preparations is a controversial issue in the management of anemia in chronic kidney disease (CKD), as direct head-to-head comparative trials are lacking. In this study, patients of CKD were randomized to receive intravenous low molecular weight iron dextran (ID), sodium ferrigluconate complex (SFGC), and iron sucrose (IS) at doses and infusion rates recommended by the product manufacturer. One time test dose was used only for ID and SFGC. A total of 2,980 injections (n = 339) of i.v. iron was given, and 49 patients (14.45% per patient) and a total of 56 adverse events (1.88% per infusion) were noted. Odds ratios (OR) of serious adverse drug events (ADE; i.e., death, anaphylaxis, or suspected immuno-allergic events) per patient was not significant between ID vs. SFGC (3.566) and SFGC vs. IS (2.129), whereas that between ID vs. IS (7.594) was highly significant (p = 0.034). OR of serious ADE exposure was significantly higher in ID vs. SFGC (OR = 5.670, p = 0.0147) and ID vs. IS (OR = 7.799, p < 0.001). No significant difference was seen between the three groups in terms of non-serious ADEs. Drug discontinuation occurred significantly more often with ID. One patient who developed anaphylactoid reaction with SFGC and ID tolerated iron sucrose well.

Efficacy and safety of intravenous iron therapy as an alternative/adjunct to allogeneic blood transfusion

Anaemia is a common condition among patients admitted to hospital medicosurgical departments, as well as in critically ill patients. Anaemia is more frequently due to absolute iron deficiency (e.g. chronic blood loss) or functional iron deficiency (e.g. chronic inflammatory states), with other causes being less frequent. In addition, preoperative anaemia is one of the major predictive factors for perioperative blood transfusion. In surgical patients, postoperative anaemia is mainly caused by perioperative blood loss, and it might be aggravated by inflammation-induced inhibition of erythropoietin and functional iron deficiency (a condition that cannot be corrected by the administration of oral iron). All these mechanisms may be involved in the anaemia of the critically ill. Intravenous iron administration seems to be safe, as very few severe side-effects were observed, and may result in hastened recovery from anaemia and lower transfusion requirements. However, it is noteworthy that many of the recommendations given for intravenous iron treatment are not supported by a high level of evidence and this must be borne in mind when making decisions regarding its application to a particular patient. Nonetheless, this also indicates the need for further large, randomized controlled trials on the safety and efficacy of intravenous iron for the treatment of anaemia in different clinical settings.

[Prevalence and treatment of anemia in critically ill patients]

Anemia is a common condition among medical and surgical patients admitted to the intensive care unit (ICU) and generally has a multifactorial origin. In order to avoid the deleterious effects of anemia, 40% of ICU patients receive allogenic blood transfusion (ABT). This figure increases up to 70% if the ICU stay is longer than 7 days. However, ABT is associated with a dose-dependent increase in morbidity and mortality. In contrast, the administration of exogenous erythropoietin plus iron supplements, especially iv iron, improves anemia and reduces ABT requirements, although it does not reduce mortality. To ascertain whether treatment of anemia in the critically ill with exogenous erythropoietin and iron might improve outcomes and to optimize drug administration schedules and dosage, further studies with sufficient statistical power and adequate follow-up are warranted.

Intravenous iron sucrose in Chinese hemodialysis patients with renal anemia

BACKGROUND/AIMS

Renal anemia is one of the commonest complications of chronic renal failure. Iron deficiency is the most common factor which affects the efficacy of recombinant human erythropoietin (EPO) therapy. Intravenous (i.v.) iron preparations are commonly used in Western countries, but iron sucrose is seldom used in Chinese patients on maintenance hemodialysis. The aim of the present study was to explore the safety and efficacy of i.v. iron sucrose in Chinese patients on maintenance hemodialysis and to explore the optimal administration frequency.

METHODS

One hundred and thirty-six patients on maintenance hemodialysis were involved in this randomized, controlled, parallel-group, single-center trial. Seventy patients received i.v. iron sucrose (Venofer(R), delivering 100 mg iron) twice a week for 8 weeks, then once a week for another 4 weeks. The other 66 patients received oral (p.o.) ferrous succinate 200 mg t.i.d. for 12 weeks. Levels of serum ferritin (SF), transferrin saturation (TSAT), hemoglobin (Hb) and hematocrit (Hct) were assessed at baseline and then again after 4, 8 and 12 weeks of treatment.

RESULTS

There were no differences between i.v. and p.o. groups in terms of sex, age, duration of hemodialysis, dialysis frequency per week, EPO dosage per week, the level of intact parathyroid hormone, serum creatinine, blood urea nitrogen, or hematological parameters at baseline. After 8 and 12 weeks of treatment, mean Hb concentration and Hct were significantly increased in the i.v. group, and were also significantly higher than those in the p.o. group. Levels of SF and TSAT were also significantly increased in the i.v. group, and significantly higher than in the p.o. group. After 8 weeks, the response rate in the i.v. group was 88.6%, which was significantly higher than that in the p.o. group. The mean EPO dose was significantly lower in the i.v. group than the p.o. group. Hb, Hct, SF and TSAT levels were maintained between 8 and 12 weeks in the i.v. group despite the decrease in dose frequency. There were no adverse events related to i.v. iron administration. Twenty-two patients in the p.o. group had adverse gastrointestinal effects. After 12 weeks, the cost of EPO + i.v. iron was significantly higher than the cost of EPO + p.o. iron.

CONCLUSION

Intravenous iron sucrose can effectively increase serum iron parameters and Hb levels in Chinese patients on maintenance hemodialysis and is well tolerated. Infusion of i.v. iron sucrose 100 mg per week can maintain serum iron parameters and Hb levels in Chinese patients on maintenance hemodialysis and can permit reductions in the required dose of EPO. However, the total cost of i.v. iron is relatively high.

Extended-dosage-interval regimens of erythropoietic agents in chemotherapy-induced anemia

PURPOSE

The safety and efficacy of extended-dosage-interval regimens of erythropoiesis-stimulating agents (ESAs) for managing chemotherapy-induced anemia (CIA) are reviewed.

SUMMARY

Anemia is a frequent complication of chemotherapy. The ESAs epoetin alfa and darbepoetin alfa have been shown to safely and effectively manage CIA; comparable outcomes have been demonstrated between epoetin alfa 40,000 units once weekly and darbepoetin alfa 200 microg every two weeks. These commonly prescribed regimens necessitate extra clinic visits by cancer patients receiving cyclic chemotherapy. ESA administration can now often be synchronized with a three-week chemotherapy cycle because of the recent approval of darbepoetin alfa 500 microg every three weeks for CIA. However, in the Phase III trial providing the basis for this new dosage recommendation, more than 70% of patients required a 40% reduction in the dosage, resulting in an average dose of 375 microg every three weeks. The extended-dosage-interval regimens have not been associated with an increase in cardiovascular or thrombotic adverse events. Extended-dosage-interval regimens of epoetin alfa are under investigation and may provide additional alternatives. Synchronizing ESA therapy with scheduled chemotherapy visits would help minimize disruptions for patients and caregivers and improve the use of health care resources.

CONCLUSION

Administration of darbepoetin alfa every three weeks offers the convenience of synchronization of treatment with 21-day-cycle chemotherapy in many patients with CIA. Extended-dosage-interval regimens for epoetin alfa are being investigated and show promise.

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.

A randomized controlled trial of oral versus intravenous iron in chronic kidney disease

BACKGROUND

It is unknown whether intravenous iron or oral iron repletion alone can correct anemia associated with chronic kidney disease (CKD). We conducted a randomized multicenter controlled trial in adult anemic, iron-deficient non-dialysis CKD (ND-CKD) patients (>or=stage 3) not receiving erythropoiesis-stimulating agents (ESAs).

METHODS

The participants were randomized to receive either a sodium ferric gluconate complex (intravenous iron) 250 mg i.v. weekly x 4 or ferrous sulfate (oral iron) 325 mg t.i.d. x 42 days. Hemoglobin (Hgb), ferritin and transferrin saturation (TSAT) were measured serially, and the Kidney Disease Quality of Life (KDQoL) questionnaire was administered on days 1 and 43. The primary outcome variable was change from baseline (CFB) to endpoint in Hgb values.

RESULTS

Seventy-five patients were analyzed (intravenous iron n = 36, oral iron n = 39). CFB in Hgb was similar in the two groups (intravenous iron 0.4 g/dl vs. oral iron 0.2 g/dl, p = n.s.). However, the increase in Hgb was only significant with intravenous iron (p < 0.01). In comparison to oral iron, intravenous iron achieved greater improvements in ferritin (232.0 +/- 160.8 vs. 55.9 +/- 236.2 ng/ml, p < 0.001) and TSAT (8.3 +/- 7.5 vs. 2.9 +/- 8.8%, p = 0.007). Intravenous iron caused greater improvements in KDQoL scores than oral iron (p < 0.05). The most common side effect reported with intravenous iron was hypotension, while constipation was more common with oral iron.

CONCLUSIONS

Oral and intravenous iron similarly increase Hgb in anemic iron-depleted ND-CKD patients not receiving ESAs. Although in comparison to oral iron, intravenous iron may result in a more rapid repletion of iron stores and greater improvement in quality of life, it exposes the patients to a greater risk of adverse effects and increases inconvenience and cost.

Treatment of iron deficiency anemia with intravenous iron preparations

OBJECTIVE

We aimed to determine the effects of intravenous iron therapy on blood parameters in pediatric patients who do not tolerate oral iron therapy for any reason.

PATIENTS AND METHODS

The patient group consisted of candidates for elective operations requiring blood transfusions in order to raise hemoglobin (Hb) concentrations rapidly and for whom oral iron administration is useless and compliance with long-term treatment is definitely impossible due to sociocultural factors. Sixty-two children were included in the study. Venous blood samples were taken at diagnosis, and after 1 week and 1, 2 and 3 months. Hb, hematocrit, erythrocyte indices (mean erythrocyte volume, mean erythrocyte Hb and mean erythrocyte Hb concentration), serum iron (SI) levels, iron binding capacity, transferrin receptor (CD71) and serum ferritin levels were measured. Iron sucrose was used as an intravenous iron preparation.

RESULTS

All children showed improvements in iron deficiency anemia. A statistically significant elevation occurred between the time of diagnosis and week 1 (p<0.05) in nearly all parameters. SI was raised until at least 1 month of therapy. There was no significant difference between transferrin receptors measured before and after the intravenous iron therapy. Ferritin did not exceed the values achieved in the 1st month. Mild side effects were encountered in only 8 (12.9%) patients. Treatment was not discontinued because of side effects in any case. The patients in the control group were given an oral form containing ferroglycine sulfate.

CONCLUSION

Intravenous iron therapy can replace oral therapy in patients whose blood parameters must be raised rapidly and in situations where oral iron administration would not be appropriate for any reason. However, reinforcement with oral iron therapy or additional intravenous doses would be appropriate.

Determination of the iron state in ferrous iron containing vitamins and dietary supplements: Application of Mössbauer spectroscopy

Determination of the iron state in commercially manufactured iron containing vitamins and dietary supplements is important for evaluation of pharmaceuticals quality. Mössbauer (nuclear gamma-resonance) spectroscopy was used for analyzing the iron state in commercial pharmaceutical products containing ferrous fumarate (FeC(4)H(2)O(4)), ferrous sulfate (FeSO(4)), ferrous bisglycinate chelate (Ferrochel) and ferrous iron (hydrolyzed protein chelate). Mössbauer parameters and the iron states were determined for iron compounds in the studied pharmaceuticals. Various ferric and ferrous impurities were found in all of the commercial products. The quantities of ferric impurities exceeded the FDA limitation of 2% in products containing ferrous fumarate. The quantities of ferric impurities exceeded 58% and 30% in products containing ferrous bisglycinate chelate and ferrous iron (hydrolyzed protein chelate), respectively. The presence of ferrous and ferric impurities was not related to the ageing of the vitamins and dietary supplements. Two pharmaceutical products contained major iron compounds, the Mössbauer parameters of which did not correspond to the ferrous fumarate or ferrous bisglycinate chelate claimed by the manufacturer.

Intravenous iron therapy: well-tolerated, yet not harmless

In the majority of patients with chronic renal failure, it is essential to substitute erythropoietic agents and iron to maintain a haemoglobin level above 11 g dL-1. Intravenous iron is more effective than oral iron. Substitution of intravenous iron is mainly performed using iron(III)-hydroxide-sucrose complex (iron sucrose) and iron(III)-sodium-gluconate in sucrose (iron gluconate), and is, in general, well-tolerated. Nonetheless, intravenous iron therapy has effects on endothelial cells, polymorphonuclear leucocytes and cytokines which are most likely related to non-transferrin bound labile iron. These effects suggest a role of iron in infection or atherosclerosis. Yet, not all available data support the association of iron with infection and atherosclerosis. A recent trial showed that iron sucrose is safe when given as treatment for iron deficiency or for maintenance of iron stores. Nevertheless, iron therapy should be handled with caution but its use should not be feared whenever indicated.

Update on adverse drug events associated with parenteral iron

BACKGROUND

We previously compared the safety profile of three formulations of intravenous iron used during 1998-2000 and found higher rates of adverse drug events (ADEs) associated with the use of higher molecular weight iron dextran and sodium ferric gluconate complex compared with lower molecular weight iron dextran. Since that time, iron sucrose has become widely available and clinicians have gained additional experience with sodium ferric gluconate complex.

METHODS

We obtained data from the United States Food and Drug Administration (FDA) on ADEs attributed to the provision of four formulations of intravenous iron during 2001-2003, including higher and lower molecular weight iron dextran, sodium ferric gluconate complex and iron sucrose. We estimated the odds of intravenous iron-related ADEs using 2 x 2 tables and the chi(2) test.

RESULTS

The total number of reported parenteral iron-related ADEs was 1141 among approximately 30,063,800 doses administered, yielding a rate of 3.8 x 10(-5), or roughly 38 per million. Eleven individuals died in association with the ADE. Relative to lower molecular weight iron dextran, total and life-threatening ADEs were significantly more frequent among recipients of higher molecular weight iron dextran and significantly less frequent among recipients of sodium ferric gluconate complex and iron sucrose. The absolute rates of life-threatening ADEs were 0.6, 0.9, 3.3 and 11.3 per million for iron sucrose, sodium ferric gluconate complex, lower molecular weight iron dextran and higher molecular weight iron dextran, respectively. Based on differences in the average wholesale price of iron sucrose and lower molecular weight iron dextran in the US, the cost to prevent one life-threatening ADE related to the use of lower molecular weight iron dextran was estimated to be 5.0-7.8 million dollars. The cost to prevent one lower molecular weight iron dextran-related death was estimated to be 33 million dollars.

CONCLUSIONS

The frequency of intravenous iron-related ADEs reported to the FDA has decreased, and overall, the rates are extremely low. This is the fourth report suggesting increased risks associated with the provision of higher molecular weight iron dextran. Life-threatening and other ADEs appear to be lower with the use of non-dextran iron formulations, although the cost per ADE prevented is extremely high.

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

BACKGROUND

Two new intravenous (IV) iron products, ferric gluconate and iron sucrose, recently were approved for use in the United States. We report trends in IV iron use in both incident (1994 to 2001) and prevalent (1994 to 2002) Medicare US dialysis patients.

METHODS

Included patients had Medicare as a primary payer. Recombinant human erythropoietin doses, IV iron use, and hemoglobin data were obtained from Medicare outpatient files. The most recent cohorts included 241,770 prevalent hemodialysis (HD) patients in 2002 and 11,744 incident HD patients in 2001.

RESULTS

For incident HD patients in the first 9 months of dialysis therapy, the percentage of patients administered IV iron increased sharply between 1994 and 1997 and then increased gradually between 1997 and 2001. In 2002, a total of 84.4% of HD and 19.3% of peritoneal dialysis (PD) patients were administered IV iron. Ferric gluconate use increased slowly in 2000, increased from 5.7% to 18.6% from December 2000 to January 2001, increased to 29.8% in April 2002, and was 23.3% in December 2002. Iron sucrose use increased to 26% by December 2002. The absolute monthly percentage of HD patients administered IV iron dextran decreased from 49.6% in January 2000 to 3.6% in December 2002.

CONCLUSION

In US patients with end-stage renal disease, IV iron use has increased, although slowly, from 1997 to 2002. Ferric gluconate and iron sucrose have become the predominant form of therapy. IV iron therapy was used in a much smaller percentage of PD compared with HD patients, and racial and geographic variability was observed.

Dose-dependent effect of parenteral iron therapy on bleomycin-detectable iron in immune apheresis patients

BACKGROUND

Iron deficiency and anemia are commonly encountered in patients with autoimmune diseases undergoing immune apheresis. This makes erythropoietin and iron substitution necessary in most patients. However, intravenous iron therapy may result in an increase of potentially toxic nontransferrin-bound iron.

METHODS

We examined the effect of 50 mg or 100 mg of iron (III) sucrose on bleomycin-detectable iron (BDI) in immune apheresis patients. Six patients with autoimmune disorders and normal kidney function were enrolled. Before and after the injection of 50 mg or 100 mg of iron (III) sucrose, BDI was measured in serum samples at five different time points.

RESULTS

There was no BDI traceable before injection of iron (III) sucrose. BDI was present in serum of all patients after the administration of 100 mg of iron (III) sucrose in concentrations up to 0.49 micromol/L. In contrast, only one patient showed BDI at a concentration of 0.16 micromol/L after the administration of 50 mg of iron (III) sucrose.

CONCLUSION

We conclude that if parenteral iron is administered after apheresis treatment, despite the equal tolerability, use of 50 mg of iron (III) sucrose is superior to 100 mg of iron (III) sucrose in avoiding the formation of potentially toxic nontransferrin-bound iron.

On the relative safety of parenteral iron formulations

BACKGROUND

Intravenous iron is usually required to optimize the correction of anaemia in persons with advanced chronic kidney disease and end-stage renal disease. Randomized clinical trials may have insufficient power to detect differences in the safety profiles of specific formulations.

METHODS

We obtained data from the US Food and Drug Administration on reported adverse drug events (ADEs) related to the provision of three formulations of intravenous iron during 1998-2000. We estimated the relative risks [odds ratios (OR)] of ADEs associated with the use of higher molecular weight iron dextran and sodium ferric gluconate complex compared with lower molecular weight iron dextran using 2 x 2 tables.

RESULTS

The total number of reported parenteral iron-related ADEs was 1981 among approximately 21,060,000 doses administered, yielding a rate of 9.4 x 10(-5), or approximately 94 per million. Total major ADEs were significantly increased among recipients of higher molecular weight iron dextran (OR 5.5, 95% CI 4.9-6.0) and sodium ferric gluconate complex (OR 6.2, 95% CI 5.4-7.2) compared with recipients of lower molecular weight iron dextran. We observed significantly higher rates of life-threatening ADEs, including death, anaphylactoid reaction, cardiac arrest and respiratory depression among users of higher molecular weight compared with lower molecular weight iron dextran. There was insufficient power to detect differences in life-threatening ADEs when comparing lower molecular weight iron dextran with sodium ferric gluconate complex.

CONCLUSIONS

Parenteral iron-related ADEs are rare. Using observational data, overall and most specific ADE rates were significantly higher among recipients of higher molecular weight iron dextran and sodium ferric gluconate complex than among recipients of lower molecular weight iron dextran. These data may help to guide clinical practice, as head-to-head clinical trials comparing different formulations of intravenous iron have not been conducted.

The effects of iron dextran on the oxidative stress in cardiovascular tissues of rats with chronic renal failure

BACKGROUND

Redox-active iron can promote oxidative stress and tissue injury by catalyzing hydroxyl radical generation and lipid peroxidation. Intravenous iron preparations are routinely administered in conjunction with erythropoietin to treat anemia in patients with chronic renal failure (CRF), a condition that is marked by oxidative stress and inflammation. This treatment frequently elevates iron burden, which can potentially intensify oxidative stress and, thus, cardiovascular disease in this population.

METHODS

We studied renal function and oxidative stress parameters in the cardiovascular tissues of CRF (5/6 nephrectomized) and sham-operated control rats 3 months after a single intravenous infusion of iron dextran (500 mg/kg).

RESULTS

Arterial pressure was equally elevated and creatinine clearance was equally reduced in both iron-treated and -untreated CRF groups. Iron administration significantly raised the blood hemoglobin, serum iron concentration, and transferrin saturation in both CRF and control groups. Iron administration resulted in a significant rise in plasma concentration of lipid peroxidation product, malondialdehyde in the CRF rats, and an insignificant rise in the control group. Plasma oxidized low-density lipoprotein (LDL) concentration was increased in the CRF groups, and was not affected by iron administrations. Iron administration raised nitrotyrosine abundance in the aorta of CRF but not in the control group. Left ventricular tissue abundance of p22(phox) subunit of NAD(P)H oxidase was elevated in CRF group and was not affected, whereas p67(phox) subunit abundance was raised by prior iron administration. Iron administration insignificantly lowered aorta p22(phox), but had no effect on p67(phox) subunit abundance in the treated CRF group. Previous iron administration significantly lowered superoxide dismutase and catalase abundance in the aorta and glutathione peroxidase in the left ventricle of CRF animals, but did not significantly change these parameters in the iron-treated control animals.

CONCLUSION

A single intravenous injection of iron dextran increased oxidative stress in the cardiovascular tissues in the CRF group, but not the control rats, pointing to heightened susceptibility to iron-mediated toxicity in CRF. However, administration of iron dextran did not adversely affect kidney function, and favorably affected hemoglobin concentration in rats with CRF induced by renal mass reduction. Further studies are needed to explore the effects of other parenteral iron preparations, repeated intravenous iron administration, and presence of comorbid conditions such as diabetes.

Anemia in the critically ill

The anemia of critical illness is a distinct clinical entity with characteristics similar to that of chronic disease anemia. Several solutions to the processes of anemia, such as blunted erythropoietin production and erythropoietin response and abnormalities in iron metabolism have been developed. The transfusion of RBCs provides immediate correction of low hemoglobin levels, which may be of value in patients with life-threatening anemia. Avoidance of RBC and blood component transfusion, however, is becoming increasingly important as data of adverse clinical outcomes in critically ill patients become clearer. Although the optimal hemoglobin in critically ill patients is not determined, this organ system has a generous reserve. Short-term compensated anemia is tolerated well, while exogenous erythropoietin allows patients to achieve higher hemoglobin concentrations without exposure to transfused blood/blood components. A recent randomized trial enrolled over 1300 critically ill patients to receive either 40,000 units of exogenous erythropoietin or placebo. These authors found that patients randomized to erythropoietin received significantly less allogeneic RBC transfusions and had significantly greater increases in hemoglobin. Although no differences were found between groups in gross clinical outcomes (ie, death, renal failure, myocardial infarction), this study did not have the power to identify small differences in outcomes. This and other studies of exogenous erythropoietin therapy in critically ill patients clearly demonstrate that the bone marrow in many of these patients will respond to the administration of erythropoietin despite their illness, suggesting a blunted production of erythropoietin rather than a blunted response to erythropoietin. Exogenous erythropoietin therefore represents a therapeutic option for treating anemia in critical illness. Acute events in medicine and surgery often lead to many patients becoming anemic. Solutions to this process of anemia should be focused on preventing such events. Anemia after surgery represents an area for prevention. Blood conservation strategies can be performed with adequate results. Monk et al randomized 79 patients undergoing radical prostatectomy to preoperative autologous donation (PAD), preoperative exogenous erythropoietin therapy plus ANH immediately following induction of general anesthesia, and ANH alone. This study concluded that all three techniques resulted in similar hemostasis outcomes (eg, bleeding and transfusion rates), but ANH alone was the least expensive, and ANH plus exogenous erythropoietin and ANH alone resulted in a higher ICU hematocrit compared with PAD. Regardless of these prophylactic strategies, patients still become anemic after surgery or during critical illness. This acute event anemia usually is treated with RBC transfusion; however, autologous blood recovery (cell salvage systems) has been shown to be effective in patients with acute bleeding-related anemia, and this may reduce patients' exposure to allogeneic blood in these patients. There are no universally accepted treatment guidelines for managing anemia, and practice differs between clinicians, hospitals, regions, and countries. Transfusion medicine is evolving and incorporating many new pharmacological agents into the armamentarium of anemia and bleeding therapy. Accumulating evidence suggests that anemia in critically ill patients is common and correlated with poor outcomes. The management of anemia can improve outcomes; however, the optimal management of anemia is not performed universally. New approaches, continued research, and an understanding of anemia may result in more consistent and improved outcomes for critically ill patients.

Low-dose continuous iron therapy leads to a positive iron balance and decreased serum transferrin levels in chronic haemodialysis patients

BACKGROUND

Iron balance is critical for adequate erythropoiesis, but its optimal therapeutic regimen remains to be defined. Continuous maintenance therapy with iron has been proposed for dialysis patients on recombinant human erythropoietin (rHuEpo) in the hope that the regimen is adequate and safe.

METHODS

We determined serum ferritin, transferrin, transferrin saturation (TSAT), serum transferrin receptors, albumin and C-reactive protein (CRP) in a 3-year prospective study in 30 chronic haemodialysis patients on dialysis treatment for 132+/-111 months (18 males, 12 females; mean age 56+/-14 years). Beginning in the year 2000, they regularly received low-dose maintenance iron supplementation (i.v. iron gluconate 31.25 mg/week) for 12 months (Period 1 or first treatment phase), followed by a 6-month withdrawal (Period 2 or stop phase) and then by continuous maintenance iron therapy (i.v. iron gluconate 31.25 mg/week) for another 9 months (Period 3 or re-challenge phase).

RESULTS

A significant increase in serum ferritin and TSAT was observed, with values exceeding 500 ng/ml and 50% in 10/30 (33%) and 7/30 (23%) of subjects, respectively, in Period 1, and in 11 and 5% in Period 3. A significant decrease in serum transferrin was documented during Period 1, followed by an increase in Period 2 and a decrease in Period 3. Serum albumin remained stable. Serum transferrin was always negatively correlated with ferritin (r = -0.41, P<0.001) and weakly correlated with serum transferrin receptors (r = 0.178, P<0.05), but was not correlated with serum albumin or CRP. Regression equations based on pre-treatment serum ferritin values were developed for predicting the value of serum ferritin at any time following the beginning of continuous iron supplementation. They fitted a linear relationship for males (y = 81 + 21.5 x time) and for females (y = 65 + 22 x time). Percentile charts for quantitative tracking of serum ferritin increases and decreases in patients have also been developed from values measured at different times. These charts show box-plot distributions of expected ferritin against time.

CONCLUSIONS

Even continuous low-dose maintenance iron therapy, with only 31.25 mg weekly over 1 year, cannot prevent the risk of iron overload in patients with moderate anaemia. Furthermore, this treatment is responsible for decreases in serum transferrin, unrelated to changes in serum albumin, possibly of concern for hypo-transferrinaemia as an independent risk factor for iron toxicity.