In older adults, iron dextran and ferumoxytol each had higher anaphylaxis risk at ≤1 d than iron sucrose.

SOURCE CITATION: Dave CV, Brittenham GM, Carson JL, et al. Risks for anaphylaxis with intravenous iron formulations: a retrospective cohort study. Ann Intern Med. 2022;175:656-64. 35344378.

Risks for Anaphylaxis With Intravenous Iron Formulations : A Retrospective Cohort Study.

BACKGROUND: The risks for anaphylaxis among intravenous (IV) iron products currently in use have not been assessed. OBJECTIVE: To compare risks for anaphylaxis among 5 IV iron products that are used frequently. DESIGN: Retrospective cohort study using a target trial emulation framework. SETTING: Medicare fee-for-service data with Part D coverage between July 2013 and December 2018. PARTICIPANTS: Older adults receiving their first administration of IV iron. MEASUREMENTS: The primary outcome was the occurrence of anaphylaxis within 1 day of IV iron administration, ascertained using a validated case definition. Analysis was adjusted for 40 baseline covariates using inverse probability of treatment weighting. The adjusted incidence rates (IRs) for anaphylaxis per 10 000 first administrations and odds ratios (ORs) were computed. RESULTS: The adjusted IRs for anaphylaxis per 10 000 first administrations were 9.8 cases (95% CI, 6.2 to 15.3 cases) for iron dextran, 4.0 cases (CI, 2.5 to 6.6 cases) for ferumoxytol, 1.5 cases (CI, 0.3 to 6.6 cases) for ferric gluconate, 1.2 cases (CI, 0.6 to 2.5 cases) for iron sucrose, and 0.8 cases (CI, 0.3 to 2.6 cases) for ferric carboxymaltose. Using iron sucrose as the referent category, the adjusted ORs for anaphylaxis were 8.3 (CI, 3.5 to 19.8) for iron dextran and 3.4 (CI, 1.4 to 8.3) for ferumoxytol. When cohort entry was restricted to the period after withdrawal of high-molecular-weight iron dextran from the U.S. market in 2014, the risk for anaphylaxis associated with low-molecular-weight iron dextran (OR, 8.4 [CI, 2.8 to 24.7]) did not change appreciably. Anaphylactic reactions requiring hospitalizations were observed only among patients using iron dextran or ferumoxytol. LIMITATION: Generalizability to non-Medicare populations. CONCLUSION: The rates of anaphylaxis were very low with all IV iron products but were 3- to 8-fold greater for iron dextran and ferumoxytol than for iron sucrose. PRIMARY FUNDING SOURCE: None.

A retrospective study of the safety and efficacy of low molecular weight iron dextran for children with iron deficiency anemia.

BACKGROUND: Iron deficiency anemia (IDA) affects millions of children worldwide. Oral iron replacement is effective but often poorly tolerated. Intravenous iron has been demonstrated to have utility in all ages, but pediatric use remains limited. Low molecular weight iron dextran (LMWID) has a dosing range capable of replacing iron deficits in a single infusion and has been evaluated in small pediatric cohorts, but additional safety and efficacy data are limited. Here, we evaluate the safety and efficacy of LMWID in association with an electronic medical record (EMR)-based effort to optimize dosing. PROCEDURE: A retrospective IRB-approved investigation of LMWID utilization at a tertiary pediatric hospital between January 1, 2016 and March 31, 2020 was undertaken to evaluate the therapeutic efficacy and frequency/severity of infusion-related adverse event (AE) in children and adolescents receiving LMWID. Patient demographics and LMWID dosing characteristics were collected, and primary outcome measures included laboratory response and the incidence/severity of any infusion-related events. The utilization of an EMR-based nomogram for LMWID dosing was also evaluated. RESULTS: A total of 254 infusions for 191 patients were included (ages 0.7-20.9 years), most with IDA. LMWID replaced at least 75% of the estimated iron deficit in a single infusion for 76% of patients. The mean hemoglobin and ferritin increases were 2.1 g/dl and >100 ng/ml, respectively. Infusion-related AEs were rare, occurring in only 12/254 (4.7%) of infusions and 67% during the test dose; each rapidly resolved without long-term sequelae. No AEs occurred in those <10 years of age. Premedication use markedly decreased with nomogram use without a change in AE rate. CONCLUSIONS: In a large institutional cohort, LMWID was well tolerated in children and adolescents, with most patients having their total iron deficits relieved in a single infusion. These data support expanded use of LMWID in the management of pediatric iron deficiency.

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.

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.

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).

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.

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.

Intravenous iron-containing products: EMA procrastination.

A European reassessment has led to identical changes in the summaries of product characteristics (SPCs) for all intravenous iron-containing products: the risk of serious adverse effects is now highlighted, underlining the fact that intravenous iron-containing products should only be used when the benefits clearly outweigh the harms. Unfortunately, iron dextran still remains on the market despite a higher risk of hypersensitivity reactions than with iron sucrose.

Intravenous low molecular weight iron dextran in children with iron deficiency anemia unresponsive to oral iron.

BACKGROUND: Iron deficiency anemia (IDA) in children is usually treated with oral iron, yet many respond poorly. Intravenous low molecular weight iron dextran (LMWID) offers the opportunity of employing a single outpatient infusion to correct the anemia and reduce the overall burden of treatment, but its use in children has been limited due to concerns of serious adverse effects. In this study we report our initial experience using LMWID in children with iron deficiency in whom oral iron was ineffective. METHODS: We performed a case series of LMWID treatment of children with IDA of diverse etiologies who were poorly responsive to oral iron therapy with the aim of measuring its efficacy and adverse effects. LMWID was administered as a total dose infusion over 60 minutes in the outpatient setting. RESULTS: Thirty-one patients age 11 months to 18 years received intravenous LMWID, and 24 were evaluable for hematologic response. Median hemoglobin increments were respectively 3.5, 1.9, and 1.8 g/dl in patients with IDA due to poor nutrition (n = 11), chronic blood loss (n = 13), and miscellaneous causes (n = 7). Two thirds of evaluable patients had a complete hematologic response. Nine of the patients (29%) had mild non-specific adverse effects upon initiation of the LMWID infusion. CONCLUSIONS: LMWID as a total dose infusion was well tolerated and effective in a heterogeneous group of children and adolescents with IDA who were refractory to oral iron therapy. Transient reactions were common but not serious.

[Importance of the different i.v. iron generations for everyday medical practice]. / Bedeutung der verschiedenen i.v.-Eisengenerationen für den medizinischen Alltag.

BACKGROUND: Iron deficiency and anaemia occur in particular in women or as comorbid conditions to a varietyof chronic diseases. Besides oral preparations, parenteral iron therapies are also available for the treatment of iron deficiency or anaemia. In the light of the growing importance and increasing number of parenteral iron preparations, theirpharmacology and application as well as the chronology of their approvals and thecharacteristicsof the various preparations are presented herefor comparison. METHOD: Review. RESULTS: To date, there are three different generations of parenteral iron preparations, which differ in terms of stability, safety and dosage. In particular, the active substances of the third generation, ferric carboxymaltose, iron isomaltoside and ferumoxytol are characterised by high complex stability and comparable safety, also allowing rapid application of high doses of iron. CONCLUSIONS: High molecular weight iron dextran, as a representative of 1st generation iron preparations, should no longer be used if possible, as more recent i.v. iron preparations are available with considerably lower risk of serious anaphylactic reactions. Ferrous gluconate and iron sucrose, as representatives of the 2nd generation, are very efficient preparations, but they require frequent visits to the clinic or the doctor, as they may only be administered in low doses because of labile iron complexes. The three 3rd generation parenteral iron formulations have advantages in handling in everyday practice, since they offer comparably good safety profiles, high complex stability and thus the possibility of rapid application of high doses of iron up to the total cumulative dose. Furthermore, test doses are not required with these preparations, which also simplifies their use.

Total dose iron dextran infusion in cancer patients: is it SaFe2+?

The feasibility of the large, single-dose intravenous iron repletion method, which is known today as total dose infusion (TDI), has been demonstrated over decades. However, this method of iron repletion was chiefly developed for patients with large iron deficits, such as those with pregnancy-induced anemia, chronic bleeding disorders, and absolute iron-deficiency anemia (serum ferritin < 30 ng/mL, transferrin saturation < 15%) who were unable to receive frequent small doses of intravenous iron. Today, 50 years after the advent of TDI, more is known about iron metabolism and storage, but the optimal dosing strategy for intravenous iron in patients with cancer is still not well defined. The proinflammatory state of cancer, or its treatment, may influence the response to intravenous iron therapy. Additionally, the long-term adverse effects of large single doses or smaller more frequent doses have yet to be studied in the oncology population. Historically, safety concerns surrounding the administration of intravenous iron have centered on anaphylaxis. Newer concerns are being raised, such as oxidative stress, iron overload, venous thromboembolism, infection risk, and tumor growth. Therefore, with the original premise of TDI assuming low levels of inflammation, coupled with the recent data surrounding the adverse effects of blood transfusions and erythropoietic-stimulating agents, this article reviews the risks and benefits of TDI administration specifically for patients with cancer.

Comparative rates of adverse events with different formulations of intravenous iron.

Oral iron replacement is the standard therapy in iron-deficiency anemia (IDA). However, 59% of patients have gastrointestinal toxicity. With impaired iron uptake from the gastrointestinal tract (in anemia of chronic disease (ACD) or after bariatric surgery), suboptimal responsiveness to exogenous erythropoietin (in chronic renal failure), in patients with cancer receiving chemotherapy, or when oral iron is poorly tolerated, IV iron therapy is the preferred mode of repletion. Although effective in increasing hemoglobin, the relative safety of the available IV iron preparations is not well documented. We examined the comparative safety of IV iron formulations used at hospitals associated with our institution. Among 619 unique patients who received IV iron over a 2-year period, we found 32 adverse events (AEs), ranging from urticaria to chest pain. There were no serious AEs or anaphylactic-type reactions. In a multivariate model, there was no difference in AE rates between low-molecular-weight iron dextran (LMWD) and ferric gluconate; however, iron sucrose had significantly higher odds ratio of AEs (OR = 5.7; 95% CI = 1.6­21.3). Our data suggest that AE rates with IV iron are acceptable. More widespread use of LMWD, in particular, which can be given safely as a total dose infusion (TDI), should be considered.

Intravenous iron therapy and risk for progressive loss of kidney function in patients with chronic kidney disease.

BACKGROUND: Intravenous (IV) iron is used in the treatment of anemia in patients with chronic kidney disease (CKD). Several lines of evidence have brought up potential concerns regarding the effect of IV iron on the kidney, specifically the possibility of IV iron leading to renal injury and hastening the progression of CKD. METHODS: We performed a retrospective analysis of 77 patients to assess the rate of change in kidney function prior to and after IV iron infusion. RESULTS: Patients were followed for an average of 21.3 months (range 2-35) prior and 32.8 months (range 2-58) after the single iron infusion. Sixty-one percent of patients had CKD stage 3 and 30% were at CKD stage IV at the time of iron infusion. Of the 77 patients, 74.1% received iron dextran and 25.9% received ferric gluconate (1 g total). The average slope before and after iron infusion for 1/serum creatinine versus time (months) were -0.0066 and -0.0053, respectively (p = 0.12). The average slope before and after iron infusion for glomerular filtration rate versus time (months) were -0.5439 and -0.2998, respectively (p = 0.14). There was no difference in subgroup analysis in the rate of change in renal function in those with more advanced renal function as opposed to those with more preserved renal function. CONCLUSION: In this limited retrospective study, IV iron dextran or ferric gluconate was not associated with a change in the rate of progression of CKD.