The Impact of the Combined Effect of Inhalation Anesthetics and Iron Dextran on Rats' Systemic Toxicity.

Disruption of any stage of iron homeostasis, including uptake, utilization, efflux, and storage, can cause progressive damage to peripheral organs. The health hazards associated with occupational exposure to inhalation anesthetics (IA) in combination with chronic iron overload are not well documented. This study aimed to investigate changes in the concentration of essential metals in the peripheral organs of rats after iron overload in combination with IA. The aim was also to determine how iron overload in combination with IA affects tissue metal homeostasis, hepcidin-ferritin levels, and MMP levels according to physiological, functional, and tissue features. According to the obtained results, iron accumulation was most pronounced in the liver (19×), spleen (6.7×), lungs (3.1×), and kidneys (2.5×) compared to control. Iron accumulation is associated with elevated heavy metal levels and impaired essential metal concentrations due to oxidative stress (OS). Notably, the use of IA increases the iron overload toxicity, especially after Isoflurane exposure. The results show that the regulation of iron homeostasis is based on the interaction of hepcidin, ferritin, and other proteins regulated by inflammation, OS, free iron levels, erythropoiesis, and hypoxia. Long-term exposure to IA and iron leads to the development of numerous adaptation mechanisms in response to toxicity, OS, and inflammation. These adaptive mechanisms of iron regulation lead to the inhibition of MMP activity and reduction of oxidative stress, protecting the organism from possible damage.

Consequences of parenteral iron-dextran loading investigated in minipigs. A new model of transfusional iron overload.

Patients with blood transfusion-dependent anemias develop transfusional iron overload (TIO), which may cause cardiosiderosis. In patients with an ineffective erythropoiesis, such as thalassemia major, common transfusion regimes aim at suppression of erythropoiesis and of enteral iron loading. Recent data suggest that maintaining residual, ineffective erythropoiesis may protect from cardiosiderosis. We investigated the common consequences of TIO, including cardiosiderosis, in a minipig model of iron overload with normal erythropoiesis. TIO was mimicked by long-term, weekly iron-dextran injections. Iron-dextran loading for around one year induced very high liver iron concentrations, but extrahepatic iron loading, and iron-induced toxicities were mild and did not include fibrosis. Iron deposits were primarily in reticuloendothelial cells, and parenchymal cardiac iron loading was mild. Compared to non-thalassemic patients with TIO, comparable cardiosiderosis in minipigs required about 4-fold greater body iron loads. It is suggested that this resistance against extrahepatic iron loading and toxicity in minipigs may at least in part be explained by a protective effect of the normal erythropoiesis, and additionally by a larger total iron storage capacity of RES than in patients with TIO. Parenteral iron-dextran loading of minipigs is a promising and feasible large-animal model of iron overload, that may mimic TIO in non-thalassemic patients.

High Prevalence of Iron Deficiency Despite Standardized High-Dose Iron Supplementation During Recombinant Erythropoietin Therapy in Extremely Low Gestational Age Newborns.

OBJECTIVE: To assess the effects of protocolized recombinant human erythropoietin (r-HuEPO) therapy and standardized high dose iron supplementation on hematologic and iron status measures in a cohort of extremely low gestational age newborns (ELGANs). STUDY DESIGN: Charts of extremely low gestational age newborns admitted from 2006 to 2016 and who had received r-HuEPO per neonatal intensive care unit protocol were reviewed. The r-HuEPO was started at a dose of 900 IU/kg per week after 7 days of age and continued until 35 weeks postmenstrual age. Oral iron supplementation at 6-12 mg/kg per day was used to maintain a transferrin saturation of >20% during r-HuEPO treatment. Data on demographic features, hematologic and iron panel indices, red blood cell transfusions, and clinical outcomes were collected. Quartile groups were created based on serum ferritin levels at the conclusion of the r-HuEPO treatment and the quartiles were compared. RESULTS: The cohort included 116 infants with mean gestational age 25.8 ± 1.5 weeks and birth weight 793 ± 174.1 g. The r-HuEPO promoted erythropoiesis as indicated by increasing hemoglobin, hematocrit, and reticulocyte count. Serum ferritin decreased over time and was ≤75 ng/mL in 60.2% of infants at the conclusion of r-HuEPO therapy; 87% received packed red blood cell transfusions. Transfusion volume, total iron intake, total iron binding capacity, and transferrin concentration differed among infants in the different serum ferritin quartiles (P < .05). CONCLUSIONS: In extremely low gestational age newborns, r-HuEPO therapy promoted erythropoiesis. Despite a biomarker-based standardized high-dose iron supplementation, the majority of infants had evidence of iron deficiency to a degree that is associated with reduced brain function.

A multicenter study evaluating the effectiveness and safety of single-dose low molecular weight iron dextran vs single-dose ferumoxytol for the treatment of iron deficiency.

There are multiple intravenous (IV) iron formulations available, of which several may be administered as single-dose infusions such as low-molecular weight iron dextran (LMWID), ferumoxytol, ferric carboxymaltose, and ferric derisomaltose. However, administration of ferumoxytol as a single-dose infusion is off-label as it is approved as a two-dose series. Previous studies of ferumoxytol alone support the effectiveness and safety of the single-dose regimen, but there is a paucity of data directly comparing single-dose ferumoxytol to other single-dose IV iron formulations. This multicenter cohort study sought to affirm the safety and effectiveness of single-dose ferumoxytol compared to single-dose LMWID. Overall, 906 patients who received single-dose LMWID (n = 439) or ferumoxytol (n = 467) were identified, of whom 351 met criteria for the primary effectiveness endpoint defined as median change in hemoglobin (Hb), hematocrit (Hct), and ferritin 8 to 12 weeks from baseline. All 906 patients were included for the secondary analysis evaluating the incidence of adverse events (AE) and requirement of additional IV iron infusions. Median change in Hb (LMWID 0.5 g/dL; ferumoxytol 0.8 g/dL; P = .24), Hct (LMWID 1.1%; ferumoxytol 1.25%; P = .89), and ferritin (LMWID 87 ng/dL; ferumoxytol 71 ng/dL; P = .47) was not significantly different between groups. Both groups experienced similar rates of AEs (LMWID 2.3%; ferumoxytol 2.8%; P = .63). The LMWID patients more frequently required additional IV iron infusions (LMWID 28.5%; ferumoxtyol 16.1%; P < .001). These findings support that single-dose ferumoxytol is effective and safe, and that patients may require fewer additional infusions compared to patients who received LMWID.

Intravenous iron supplementation does not increase infectious disease risk in hemodialysis patients: a nationwide cohort-based case-crossover study.

BACKGROUND: Studies have reported conflicting findings on the infection risk posed by intravenous iron supplementation among hemodialysis (HD) patients. We used a novel study design to assess associations between intravenous iron and infectious diseases. METHODS: Patients initiating HD between 1998 and 2008 were extracted from Taiwan's National Health Insurance Research Database. Their first infectious disease in the period between 1.5 years after dialysis initiation and 2010 was identified and defined as the index date. Through the case-crossover design, the odds of exposure to intravenous iron within the 1-month period immediately preceding the index date (i.e., the case period) were compared with iron exposure in three different matched control periods for the same enrollee, thus possibly reducing some unmeasured confounders. RESULTS: A total of 1410 patients who met our enrollment criteria were extracted from incident HD patients. The odds of intravenous iron exposure during the case period versus total control periods exhibited no significant difference (odds ratio: 1.000, 95% confidence interval: 0.75-1.33). In subgroup analyses, this association remained nonsignificant across patients with diabetes mellitus, heart failure, chronic lung disease, venous catheter for HD, and higher iron load. CONCLUSIONS: We found that intravenous iron supplementation did not increase short-term infection risk among HD patients.

An assessment for diagnostic and therapeutic modalities for management of pediatric Iron defficiency Anemia in Saudi Arabia: a crossectional study.

INTRODUCTION: Iron deficiency anemia (IDA) is a global public health issue that affect more than 2 billion individuals worldwide. However evidence for optimal management of IDA is lacking. METHODS: To assess the diagnostic criteria and therapeutic modalities for pediatric IDA employed by physicians in a major public healthcare facility in Riyadh, a validated questionnaire including demographic data and patient case-scenarios related to diagnosis and treatment of IDA was employed. Robust regression analysis was used to identify factors associated with overall score of participants. RESULTS: Of the 166 physicians surveyed 147(88.6%) were included in the study. Wide variability was observed in IDA diagnosis and therapy practises. For nutritional IDA, only 15.6% recommended no other laboratory tests in addition to CBC. The majority preferred treatment with ferrous sulfate (77.6%) divided into two doses (57.1%), but the total daily elemental iron doses varied widely from 2 to 6 mg/kg. For intravenous iron, 42.9% recommended iron dextran, 32.7% iron sucrose, and 13.4% would continue oral iron. Of all assessed factors, median score was significantly highest in pediatric hematologists compared with pediatricians, family medicine specialists and GPs; p = 0.007, and those work in tertiary care compared with those in primary care; p = 0.043. However, in multivariate robust regression analysis, overall score was only significantly associated with professional qualification [pediatric hematologist ß = 13.71,95%CI 2.48-24.95, p = 0.017; pediatrician ß = 1.77,95%C (- 6.05-9.59, p = 0.66; family medicine ß = 2.66,95%CI-4.30-9.58, p = 0.45 compared with general practitioner]. CONCLUSION: Wide variations exist among physicians in diagnosis and treatment of pediatric IDA. Intervention programs and national guidelines are urgently needed.

Treatment of Iron Deficiency Anemia in Pregnancy with Intravenous versus Oral Iron: Systematic Review and Meta-Analysis.

OBJECTIVE: To perform a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the benefits of intravenous (IV) iron in pregnancy. STUDY DESIGN: Systematic review was registered with PROSPERO and performed using PRISMA guidelines. PubMed, MEDLINE, Web of Science, ClinicalTrials.gov, Cochrane Library, and Google Scholar were searched. Eleven RCTs, comparing IV to oral iron for treatment of iron-deficiency anemia in pregnancy, were included. Meta-analyses were performed with Stata software (College Station, TX), utilizing random effects model and method of DerSimonian and Laird. Outcomes were assessed by pooled odds ratios (OR) or pooled weighted mean difference (WMD). Sensitivity analyses were performed for heterogeneity. RESULTS: We found that pregnant women receiving IV iron, compared with oral iron, had the following benefits: (1) Achieved target hemoglobin more often, pooled OR 2.66 (95% confidence interval [CI]: 1.71-4.15), p < 0.001; (2) Increased hemoglobin level after 4 weeks, pooled WMD 0.84 g/dL (95% CI: 0.59-1.09), p < 0.001; (3) Decreased adverse reactions, pooled OR 0.35 (95% CI: 0.18-0.67), p = 0.001. Results were unchanged following sensitivity analyses. CONCLUSION: In this meta-analysis, IV iron is superior to oral iron for treatment of iron-deficiency anemia in pregnancy. Women receiving IV iron more often achieve desired hemoglobin targets, faster and with fewer side effects.

Bioequivalence decision for nanoparticular iron complex drugs for parenteral administration based on their disposition.

Although parenteral iron products have been established to medicinal use decades before, their structure and pharmacokinetic properties are not fully characterized yet. With its' second reflection paper on intravenous iron-based nano-colloidal products (EMA/CHMP/SWP/620008/2012) the European Medicine Agency provided an extensive catalogue of methods for quality, non-clinical and pharmacokinetic studies for the comparison of nano-sized iron products to an originator (EMA, 2015). For iron distribution studies, the reflection paper assumed the use of rodents. In our tests, we used a turkey fetus model to investigate time dependent tissue concentrations in pharmacological and toxicological relevant tissues liver, heart and kidney. We found turkey embryos to be a suitable alternative to rodents with high discriminatory sensitivity. Clear differences were found between equimolar doses of iron products with hydroxyethyl amylopectin, sucrose, dextrane and carboxymaltose shell. A linear dose dependency for the tissue accumulation was also demonstrated.

Iron Loading Exaggerates the Inflammatory Response to the Toll-like Receptor 4 Ligand Lipopolysaccharide by Altering Mitochondrial Homeostasis.

BACKGROUND: Perioperative and critically ill patients are often exposed to iron (in the form of parenteral-iron administration or blood transfusion) and inflammatory stimuli, but the effects of iron loading on the inflammatory response are unclear. Recent data suggest that mitochondrial reactive oxygen species have an important role in the innate immune response and that increased mitochondrial reactive oxygen species production is a result of dysfunctional mitochondria. We tested the hypothesis that increased intracellular iron potentiates lipopolysaccharide-induced inflammation by increasing mitochondrial reactive oxygen species levels. METHODS: Murine macrophage cells were incubated with iron and then stimulated with lipopolysaccharide. C57BL/6 wild-type mice were intraperitoneally injected with iron and then with lipopolysaccharide. Markers of inflammation and mitochondrial superoxide production were examined. Mitochondrial homeostasis (the balance between mitochondrial biogenesis and destruction) was assessed, as were mitochondrial mass and the proportion of nonfunctional to total mitochondria. RESULTS: Iron loading of mice and cells potentiated the inflammatory response to lipopolysaccharide. Iron loading increased mitochondrial superoxide production. Treatment with MitoTEMPO, a mitochondria-specific antioxidant, blunted the proinflammatory effects of iron loading. Iron loading increased mitochondrial mass in cells treated with lipopolysaccharide and increased the proportion of nonfunctional mitochondria. Iron loading also altered mitochondrial homeostasis to favor increased production of mitochondria. CONCLUSIONS: Acute iron loading potentiates the inflammatory response to lipopolysaccharide, at least in part by disrupting mitochondrial homeostasis and increasing the production of mitochondrial superoxide. Improved understanding of iron homeostasis in the context of acute inflammation may yield innovative therapeutic approaches in perioperative and critically ill patients.

Differential Effect of Acute Iron Overload on Oxidative Status and Antioxidant Content in Regions of Rat Brain.

The hypothesis of this study is that the cerebral cortex, hippocampus, and striatum of the rat brain are differentially affected in terms of oxidative stress and antioxidant capacity by acute Fe overload because Fe is distributed in a heterogeneous fashion among different regions and cells of the brain. The effects on the lipophilic and hydrophilic cellular environment were compared between regions and with the whole brain. A single dose of Fe-dextran increased Fe deposits, reaching a maximum after 6 hr. Both in whole brain and in cortex region, the ascorbyl/ascorbate content ratio was increased after 6 hr of Fe administration, while in striatum and hippocampus, there was no significant changes after Fe overload. Total thiol content decreased in whole brain and cortex, while there were no significant changes in striatum and hippocampus after Fe overload. The content of α-tocopherol (α-T), whether measured in the whole brain or in the isolated regions, did not change following Fe treatment. Lipid radical (LR•) generation rate after Fe-dextran overload only increased in the cortex region. The LR•/α-T content ratio was increased by Fe treatment in cortex but not in the whole brain, striatum, or hippocampus, in agreement with the study tested hypothesis.

Safety and efficacy of rapid (1,000 mg in 1 hr) intravenous iron dextran for treatment of maternal iron deficient anemia of pregnancy.

Maternal iron deficiency anemia (IDA) is associated with risk of adverse perinatal outcomes. Oral iron is recommended to reverse anemia, but has gastrointestinal toxicity and frequent non-adherence. Intravenous (IV) iron is reserved for intolerance of, or unresponsiveness to, oral therapy, malabsorption, and severe anemia (1% with hemoglobin [Hgb] levels <7 g/dL). With rare (<100 per one million) adverse events (AEs) ability to infuse a sufficient dose of low molecular weight iron dextran (LMWID) over 60 min, LMWID is an attractive option. This study demonstrated safety and efficacy of rapid IV infusion of 1,000 mg LMWID to gravidas with moderate to severe IDA. An observational treatment study of 1,000 mg LMWID administered over 1 hr for IDA in 189 consecutive, unselected second and third trimester gravidas after oral iron failure was conducted. All received a test dose of 25 mg LMWID and were monitored for AEs during the 60-min infusion. No premedication was administered unless more than one drug allergy or asthma was present in which case IV methylprednisolone was administered. All were followed through pregnancy and delivery. Monitored parameters included Hgb, mean corpuscular volume, serum ferritin, and percent transferrin saturation. About 189 subjects received 1,000 mg LMWID. No serious AEs occurred. About 2% experienced transient infusion reactions. Hgb improved by 1-1.9 g/dL in 82% and ≥2 g/dL in 24%. Second trimester treatment was not associated with greater Hgb improvement than third trimester treatment. Anemia resolved in 95%. Administration of a single large dose of IV LMWID was effective, safe, and convenient. Am. J. Hematol. 91:590-593, 2016. © 2016 Wiley Periodicals, Inc.

How we diagnose and treat iron deficiency anemia.

It is estimated that one-third of the world's population is anemic, the majority being due to iron deficiency (ID). In adults, ID is associated with fatigue in the absence of anemia, restless legs syndrome, pica and, in neonates, delayed growth and development. In adolescents, ID is associated with decrements in learning and behavioral abnormalities. In the absence of a clear cause, search for a source of bleeding is indicated. No single test is diagnostic of ID unless the serum ferritin is low or the percent transferrin saturation is low with an elevated total iron binding capacity. Oral iron is considered front line therapy except for conditions such as gastric bypass, heavy uterine bleeding, inflammatory bowel disease, and hereditary hemorrhagic telangiectasia. Oral iron has many unpleasant side effects, resulting in low patient adherence. For patients intolerant of, or unresponsive to, oral iron, intravenous (IV) administration is the preferred route. While early formulations were associated with a high incidence of serious adverse events (SAEs), newer formulations are much safer with SAEs occurring very infrequently. Full replacement doses can be administered in a matter of minutes to a few hours. Nevertheless, there remains a reluctance to use IV iron due to a misunderstanding of the safety of the available formulations. IV iron is safe and effective in all clinical circumstances including pregnancy. The preponderance of published evidence suggests IV iron therapy is underutilized and we believe that IV iron should be moved forward in the treatment of ID and iron deficiency anemia (IDA).

Ferrous iron content of intravenous iron formulations.

The observed biological differences in safety and efficacy of intravenous (IV) iron formulations are attributable to physicochemical differences. In addition to differences in carbohydrate shell, polarographic signatures due to ferric iron [Fe(III)] and ferrous iron [Fe(II)] differ among IV iron formulations. Intravenous iron contains Fe(II) and releases labile iron in the circulation. Fe(II) generates toxic free radicals and reactive oxygen species and binds to bacterial siderophores and other in vivo sequestering agents. To evaluate whether differences in Fe(II) content may account for some observed biological differences between IV iron formulations, samples from multiple lots of various IV iron formulations were dissolved in 12 M concentrated HCl to dissociate and release all iron and then diluted with water to achieve 0.1 M HCl concentration. Fe(II) was then directly measured using ferrozine reagent and ultraviolet spectroscopy at 562 nm. Total iron content was measured by adding an excess of ascorbic acid to reduce Fe(III) to Fe(II), and Fe(II) was then measured by ferrozine assay. The Fe(II) concentration as a proportion of total iron content [Fe(III) + Fe(II)] in different lots of IV iron formulations was as follows: iron gluconate, 1.4 and 1.8 %; ferumoxytol, 0.26 %; ferric carboxymaltose, 1.4 %; iron dextran, 0.8 %; and iron sucrose, 10.2, 15.5, and 11.0 % (average, 12.2 %). The average Fe(II) content in iron sucrose was, therefore, ≥7.5-fold higher than in the other IV iron formulations. Further studies are needed to investigate the relationship between Fe(II) content and increased risk of oxidative stress and infections with iron sucrose.

Sub-chronic iron overload triggers oxidative stress development in rat brain: implications for cell protection.

This work was aimed to test the hypothesis that sub-chronic administration of iron-dextran (Fe-dextran) (six doses of 50 mg Fe-dextran/kg) to rats triggers a transient oxidative stress in brain and mechanisms of cellular antioxidant defence. After 2 h of administration of the 6th dose, a significant increase of total Fe, the labile Fe pool (LIP), the lipid radical (LR(•))/α-tocopherol (α-T) content ratio were observed, as compared to values in control brain homogenates. The ascorbyl radical (A(•))/ascorbate (AH(-)) content ratio and the oxidation rate of 2',7'-dichlorodihidrofluorescein (DCFH-DA) were significantly higher in Fe-dextran treated rats, as compared to values in brain from control rats after 4 h treatment. An increase in both catalase (CAT) and superoxide dismutase (SOD) activity was observed at 8 and 1-2 h, respectively. No significant changes were detected in the nuclear factor-κB (NF-κB) levels in nuclear extracts from rat brains after 1-8 h of Fe-dextran administration. After 2 h of Fe administration Fe concentration in cortex, striatum and hippocampus was significantly increased as compared to the same areas from control animals. Both, CAT and SOD activities were significantly increased in cortex after Fe administration over control values, without changes in striatum and hippocampus. Taken as a whole, sub-chronic Fe administration enhances the steady state concentration of Fe in the brain LIP that favors the settlement of an initial oxidative stress condition, both at hydrophilic and lipophilic compartments, resulting in cellular protection evidenced by antioxidant enzyme upregulation.

Cutaneous siderosis secondary to intramuscular iron dextran treated with 755 nm Q-switched alexandrite laser: A case report.

BACKGROUND: Cutaneous siderosis is accumulation of iron in the dermis and the subcutaneous tissue secondary to extravasation of an intramuscular or intravascular iron injection. It presents as varying shades of brown macules with no distinct contours. The hyperpigmentation is permanent without treatment. OBJECTIVE: Q-switched lasers have been used effectively to treat lentigines and tattoos however, there is little data on the treatment of cutaneous siderosis with lasers. Our objective was to effectively treat cutaneous siderosis with a Q-switched alexandrite laser. RESULTS: A 50-year-old female had received nine injections of intramuscular iron dextran, one injection every 2 weeks alternating right buttock and left buttock over the course of 5 months. A couple of weeks after her 9th injection which was on the left, she noted brown hyperpigmentation in the injection area with the left worse than the right. She waited 3 months for the hyperpigmentation to self-resolve before presenting in our clinic. We utilized the Q-switched alexandrite laser to treat the patient with a test spot. One week later, there was nice partial clearance from the test spot so we commenced full treatment of the hyperpigmentation. There was significant improvement after the first treatment and she has been treated 4 times with continued improvement over the past 2 months. CONCLUSION: The Q-switched alexandrite laser is a useful tool in the treatment of cutaneous siderosis secondary to iron injection.

The Use of Parenteral Iron Therapy for the Treatment of Postpartum Anemia.

Rates of postpartum hemorrhage have been increasing in Canada over the last 10 years, with postpartum iron deficiency anemia as the most common consequence. Postpartum anemia is treated with oral iron supplementation and/or blood transfusion. Recent studies have evaluated the use of parenteral iron as a better tolerated treatment modality. Compared with oral iron supplements, parenteral iron is associated with a more rapid rise in serum ferritin and hemoglobin and improved maternal fatigue scores in the postpartum period. It may also decrease rates of blood transfusion. Parenteral iron may be considered in select clinical situations for the treatment of postpartum anemia.

Les taux d'hémorragie postpartum ont connu une hausse au Canada depuis les 10 dernières années, la manifestation d'une anémie ferriprive postpartum en étant la conséquence la plus courante. L'anémie postpartum est prise en charge au moyen d'une supplémentation orale en fer et/ou d'une transfusion sanguine. De récentes études ayant évalué l'utilisation de fer parentéral ont indiqué qu'il s'agissait d'une modalité de traitement mieux tolérée. Par comparaison avec les suppléments oraux de fer, le fer parentéral est associé à une hausse plus rapide des taux sériques de ferritine et d'hémoglobine, en plus de mener à une amélioration des scores de fatigue maternelle au cours de la période postpartum. Le fer parentéral pourrait également mener à une diminution des taux de transfusion sanguine. Son utilisation pourrait être envisagée dans certaines situations cliniques particulières, aux fins de la prise en charge de l'anémie postpartum.

Comparative Risk of Anaphylactic Reactions Associated With Intravenous Iron Products.

IMPORTANCE: All intravenous (IV) iron products are associated with anaphylaxis, but the comparative safety of each product has not been well established. OBJECTIVE: To compare the risk of anaphylaxis among marketed IV iron products. DESIGN, SETTING, AND PARTICIPANTS: Retrospective new user cohort study of IV iron recipients (n = 688,183) enrolled in the US fee-for-service Medicare program from January 2003 to December 2013. Analyses involving ferumoxytol were limited to the period January 2010 to December 2013. EXPOSURES: Administrations of IV iron dextran, gluconate, sucrose, or ferumoxytol as reported in outpatient Medicare claims data. MAIN OUTCOMES AND MEASURES: Anaphylaxis was identified using a prespecified and validated algorithm defined with standard diagnosis and procedure codes and applied to both inpatient and outpatient Medicare claims. The absolute and relative risks of anaphylaxis were estimated, adjusting for imbalances among treatment groups. RESULTS: A total of 274 anaphylaxis cases were identified at first exposure, with an additional 170 incident anaphylaxis cases identified during subsequent IV iron administrations. The risk for anaphylaxis at first exposure was 68 per 100,000 persons for iron dextran (95% CI, 57.8-78.7 per 100,000) and 24 per 100,000 persons for all nondextran IV iron products combined (iron sucrose, gluconate, and ferumoxytol) (95% CI, 20.0-29.5 per 100,000) , with an adjusted odds ratio (OR) of 2.6 (95% CI, 2.0-3.3; P < .001). At first exposure, when compared with iron sucrose, the adjusted OR of anaphylaxis for iron dextran was 3.6 (95% CI, 2.4-5.4); for iron gluconate, 2.0 (95% CI 1.2, 3.5); and for ferumoxytol, 2.2 (95% CI, 1.1-4.3). The estimated cumulative anaphylaxis risk following total iron repletion of 1000 mg administered within a 12-week period was highest with iron dextran (82 per 100,000 persons, 95% CI, 70.5- 93.1) and lowest with iron sucrose (21 per 100,000 persons, 95% CI, 15.3- 26.4). CONCLUSIONS AND RELEVANCE: Among patients in the US Medicare nondialysis population with first exposure to IV iron, the risk of anaphylaxis was highest for iron dextran and lowest for iron sucrose.

Duodenal absorption and tissue utilization of dietary heme and nonheme iron differ in rats.

BACKGROUND: Dietary heme contributes to iron intake, yet regulation of heme absorption and tissue utilization of absorbed heme remains undefined. OBJECTIVES: In a rat model of iron overload, we used stable iron isotopes to examine heme- and nonheme-iron absorption in relation to liver hepcidin and to compare relative utilization of absorbed heme and nonheme iron by erythroid (RBC) and iron storage tissues (liver and spleen). METHODS: Twelve male Sprague-Dawley rats were randomly assigned to groups for injections of either saline or iron dextran (16 or 48 mg Fe over 2 wk). After iron loading, rats were administered oral stable iron in the forms of (57)Fe-ferrous sulfate and (58)Fe-labeled hemoglobin. Expression of liver hepcidin and duodenal iron transporters and tissue stable iron enrichment was determined 10 d postdosing. RESULTS: High iron loading increased hepatic hepcidin by 3-fold and reduced duodenal expression of divalent metal transporter 1 (DMT1) by 76%. Nonheme-iron absorption was 2.5 times higher than heme-iron absorption (P = 0.0008). Absorption of both forms of iron was inversely correlated with hepatic hepcidin expression (heme-iron absorption: r = -0.77, P = 0.003; nonheme-iron absorption: r = -0.80, P = 0.002), but hepcidin had a stronger impact on nonheme-iron absorption (P = 0.04). Significantly more (57)Fe was recovered in RBCs (P = 0.02), and more (58)Fe was recovered in the spleen (P = 0.01). CONCLUSIONS: Elevated hepcidin significantly decreased heme- and nonheme-iron absorption but had a greater impact on nonheme-iron absorption. Differential tissue utilization of heme vs. nonheme iron was evident between erythroid and iron storage tissues, suggesting that some heme may be exported into the circulation in a form different from that of nonheme iron.

Iron toxicity mediated by oxidative stress enhances tissue damage in an animal model of diabetes.

Although iron is a first-line pro-oxidant that modulates clinical manifestations of various systemic diseases, including diabetes, the individual tissue damage generated by active oxidant insults has not been demonstrated in current animal models of diabetes. We tested the hypothesis that oxidative stress is involved in the severity of the tissues injury when iron supplementation is administered in a model of type 1 diabetes. Streptozotocin (Stz)-induced diabetic and non-diabetic Fischer rats were maintained with or without a treatment consisting of iron dextran ip at 0.1 mL day(-1) doses administered for 4 days at intervals of 5 days. After 3 weeks, an extensive increase (p < 0.001) in the production of reactive oxygen species (ROS) in neutrophils of the diabetic animals on iron overload was observed. Histological analysis revealed that this treatment also resulted in higher (p < 0.05) tissue iron deposits, a higher (p < 0.001) number of inflammatory cells in the pancreas, and apparent cardiac fibrosis, as shown by an increase (p < 0.05) in type III collagen levels, which result in dysfunctional myocardial. Carbonyl protein modification, a marker of oxidative stress, was consistently higher (p < 0.01) in the tissues of the iron-treated rats with diabetes. Moreover, a significant positive correlation was found between ROS production and iron pancreas stores (r = 0.42, p < 0.04), iron heart stores (r = 0.54, p < 0.04), and change of the carbonyl protein content in pancreas (r = 0.49, p < 0.009), and heart (r = 0.48, p < 0.02). A negative correlation was still found between ROS production and total glutathione content in pancreas (r = -0.50, p < 0.03) and heart (r = -0.45, p < 0.04). In conclusion, our results suggest that amplified toxicity in pancreatic and cardiac tissues in rats with diabetes on iron overload might be attributed to increased oxidative stress.

Safety of total dose iron dextran infusion in geriatric patients with chronic kidney disease and iron deficiency anemia.

There are limited data on total dose infusion (TDI) using iron dextran in geriatric chronic kidney disease (CKD) patients with iron-deficiency anemia (IDA). Our goal was to evaluate the safety of TDI in this setting. We conducted a retrospective chart review spanning a 5 year period (2002-2007), including all patients with CKD and IDA who were treated with iron dextran TDI. Patient demographics were noted, and laboratory values for creatinine, hemoglobin and iron stores were recorded pre- and post-dose. TDI diluted in normal saline was administered intravenously over 4-6 hours after an initial test dose. One hundred fifty-three patients received a total of 250 doses of TDI (mean ± SD=971 ± 175 mg); age was 69 ± 12 years and creatinine 3.3 ± 1.9 mg/dL. All stages of CKD were represented (stage 4 commonest). Hemoglobin and iron stores improved post-TDI (P<0.001). None of the patients experienced an anaphylactic reaction or death. Adverse events (AEs) were noted in 8 out of 250 administered doses (3.2%). The most common AEs were itching, chills and back pain. One hundred and ten doses of high molecular weight (HMW) iron dextran produced 6 AEs (5.45%), whereas 140 doses of low molecular weight (LMW) iron dextran produced 2 AEs (1.43%), a non-significant trend (P=0.1433 by Fishers Exact Test). Iron dextran TDI is relatively safe and effective in correcting IDA in geriatric CKD patients. Fewer AEs were noted with the LMW compared to the HMW product. LMW iron dextran given as TDI can save both cost and time, helping to alleviate issues of non-compliance and patient scheduling.