The pharmacokinetics and pharmacodynamics of iron preparations

Ferric Ammonium Citrate Reduces Claudin-5 Abundance and Function in Primary Mouse Brain Endothelial Cells

BACKGROUND

Iron overload is implicated in many neurodegenerative diseases, where there is also blood-brain barrier (BBB) dysfunction. As there is a growing interest in the role of iron in modulating key BBB proteins, this study assessed the effect of iron on the expression and function of P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and claudin-5 in primary mouse brain endothelial cells (MBECs) and their abundance in mouse brain microvessel-enriched membrane fractions (MVEFs).

METHODS

Following a 48 h treatment with ferric ammonium citrate (FAC, 250 µM), MBEC protein abundance (P-gp, BCRP and claudin-5) and mRNA (abcb1a, abcg2, and cldn5) were assessed by western blotting and RT-qPCR, respectively. Protein function was evaluated by assessing transport of substrates 3H-digoxin (P-gp), 3H-prazosin (BCRP) and 14C-sucrose (paracellular permeability). C57BL/6 mice received iron dextran (100 mg/kg, intraperitoneally) over 4 weeks, and MVEF protein abundance and iron levels (in MVEFs and plasma) were quantified via western blotting and inductively coupled plasma-mass spectrometry (ICP-MS), respectively.

RESULTS

FAC treatment reduced P-gp protein by 50% and abcb1a mRNA by 43%, without affecting 3H-digoxin transport. FAC did not alter BCRP protein or function, but decreased abcg2 mRNA by 59%. FAC reduced claudin-5 protein and cldn5 mRNA by 65% and 70%, respectively, resulting in a 200% increase in 14C-sucrose permeability. In vivo, iron dextran treatment significantly elevated plasma iron levels (2.2-fold) but did not affect brain MVEF iron content or alter P-gp, BCRP or claudin-5 protein abundance.

CONCLUSIONS

Iron overload modulates BBB transporters and junction proteins in vitro, highlighting potential implications for CNS drug delivery in neurodegenerative diseases.

Imaging arterial and venous vessels using Iron Dextran enhanced multi-echo 3D gradient echo MRI at 7T

Iron Dextran is a widely used iron oxide compound to treat iron-deficiency anemia patients in the clinic. Similar to other iron oxide compounds such as Ferumoxytol, it can also be used off-label as an intravascular magnetic resonance imaging (MRI) contrast agent due to its strong iron-induced T2 and T2* shortening effects. In this study, we seek to evaluate the feasibility of using Iron Dextran enhanced multi-echo susceptibility weighted imaging (SWI) MRI at 7T to image arterial and venous blood vessels in the human brain. Phantom experiments were performed to measure the r2* relaxivity for Iron Dextran in blood, based on which the SWI sequence was optimized. Pre- and post-infusion MR images were acquired in human subjects from which maps of arteries and veins were extracted. The post-contrast SWI images showed enhanced susceptibility difference between blood and the surrounding tissue in both arteries and veins. Our results showed that the proposed Iron Dextran enhanced multi-echo SWI approach allowed the visualization of blood vessels with diameters down to ~100 μm, including small blood vessels supplying and draining small brain structures such as the hippocampus. We conclude that Iron Dextran can be an alternative iron-based MRI contrast agent for blood vessel imaging in the human brain.

Safety and Efficacy of Ferric Carboxymaltose for Iron Deficiency Anemia in Inflammatory Bowel Disease: A Systematic Review

Ulcerative colitis and Crohn's disease, two types of inflammatory bowel disease (IBD), often cause anemia, primarily due to iron deficiency and chronic inflammation. Anemia negatively affects patients' daily functioning and quality of life, causing symptoms including headaches, exhaustion, and dyspnea. In IBD, iron deficiency arises from reduced intake, chronic blood loss, and impaired absorption. While oral iron supplements are commonly used, their poor absorption and gastrointestinal side effects limit their effectiveness, especially in IBD patients. The European Crohn's and Colitis Organization (ECCO) recommends intravenous iron, such as ferric carboxymaltose (FCM), as iron deficiency anemia in IBD can be managed using a safe and efficient substitute. With regard to treating iron deficiency anemia in patients with IBD, the purpose of this study is to investigate the safety and effectiveness of intravenous ferric carboxymaltose. We conducted a thorough search of medical databases, such as the Cochrane library, PubMed, and ResearchGate, to gather relevant literature. Using the databases, we found a total of 297 relevant articles. The identified studies have been screened, eligibility criteria have been introduced, and 14 research studies were selected for inclusion. This review adhered to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, with quality assessments conducted using the Cochrane risk of bias 2 scale for randomized tests and the Newcastle-Ottawa scale for observational examination. We reviewed 14 research articles involving 2,493 patients. Among these, five were randomized controlled trials (RCTs), and the remaining nine were observational studies. The primary outcomes assessed were the therapeutic response (defined as hemoglobin ≥2 g/dL rise or normalization, improvement in iron profile parameters) and any adverse effects after FCM is administered to IBD patients. FCM was found to be highly effective in improving hemoglobin and iron profile parameters, with a generally good safety profile. Ferric carboxymaltose was the most efficient and well-tolerated intravenous (IV) iron formulation, proving safer and more effective than other iron therapies in patients suffering from IBD. However, severe hypophosphatemia can lead to serious complications, including heart failure, pulmonary failure, rhabdomyolysis, fractures, and osteomalacia, which may worsen its long-term impact. Therefore, the risk of hypophosphatemia associated with prolonged FCM use requires careful monitoring and further research to ensure its long-term safety and assess its effects on patients' quality of life.

Protocatechualdehyde inhibits iron overload-induced bone loss by inhibiting inflammation and oxidative stress in senile rats

The accumulating evidence has made it clear that iron overload is a crucial mechanism in bone loss. Protocatechualdehyde (PCA) has also been used to prevent osteoporosis in recent years. Whether PCA can reverse the harmful effects of iron overload on bone mass in aged rats is still unknown. Therefore, this study aimed to assess the role of PCA in iron overload-induced bone loss in senile rats. In the aged rat model, we observed that iron overload affects bone metabolism and bone remodeling, manifested by bone loss and decreased bone mineral density. The administration of PCA effectively mitigated the detrimental effects caused by iron overload, and concomitant reduction in MDA serum levels and elevation of SOD were noted. In addition, PCA-treated rats were observed to have significantly increased bone mass and elevated expression of SIRT3，BMP2，SOD2 and reduced expression of TNF-α in bone tissue. We also observed that PCA was able to reduce oxidative stress and inflammation and restore the imbalance in bone metabolism. When MC3T3-E1 and RAW264.7 cells induced osteoblast and osteoclasts differentiation, PCA intervention could significantly recover the restriction of osteogenic differentiation and up-regulation of osteoclast differentiation treated by iron overload. Further, by detecting changes in ROS, SOD, MDA, expression of SIRT3 and mitochondrial membrane potentials, we confirm that the damage caused to cells by iron overload is associated with decreased SIRT3 activity, and that 3-TYP have similar effects on oxidative stress caused by FAC. In conclusion, PCA can resist iron overload-induced bone damage by improving SIRT3 activity, anti-inflammatory and anti-oxidative stress.

Nutritional and Nutraceutical Support to the Failing Myocardium: A Possible Way of Potentiating the Current Treatment of Heart Failure

Heart failure (HF) is a complex condition that affects 1-2% of the global population. The presence of comorbidities like diabetes, hypertension, hyperlipidemia, or obesity has been shown in various studies to elevate mortality and hospitalization rates in HF patients. Insufficient outcomes persist in HF, necessitating additional research to address unmet needs in disease management. Lifestyle modifications, including smoking cessation, decreased alcohol consumption, regular exercise, cardiac rehabilitation, and a balanced diet, can prevent and treat a wide range of HF cases. In this review, we aimed to examine how lifestyle changes, nutrition, and nutraceutical supplements can play a role in preventing heart failure and supporting its treatment. A detailed and comprehensive analysis of the most recent data present in the literature could help identify potential candidates for future clinical trials in HF management. There is a growing body of evidence supporting the importance of closely monitoring nutritional balance, including micronutrients and nutraceuticals, in HF patients for better symptom management and outcomes. Despite promising results from initial approaches, the lack of conclusive evidence from recent studies and meta-analyses questions the widespread use of nutraceutical supplementation in HF patients. Further studies are necessary to determine the most effective way to use nutraceutical supplementation in the treatment of myocardial dysfunction in HF patients.

Clinically important interactions of macrolides and tetracyclines with dietary interventions-a systematic review with meta-analyses

BACKGROUND

Effective management of drug-food interactions is crucial for enhancing antibiotics' efficacy/safety. Adhering to PRISMA guidelines, we conducted a systematic review to assess the impact of dietary interventions on the bioavailability of 15 macrolides and 10 tetracyclines.

METHODS

We included studies examining the influence of food, beverages, antacids, and mineral supplements on the pharmacokinetic parameters of orally administered macrolides and tetracyclines. We searched Medline (via PubMed), Embase and Cochrane Library databases up to December 2022. Risk of bias was assessed using Cochrane and NIH tools. Quantitative analyses were conducted if two or more comparable food-effect studies were available; otherwise, a qualitative summary was provided.

RESULTS

We included 120 studies from 97 reports. Meta-analyses were conducted for 8 macrolides and 4 tetracyclines, with qualitative synthesis for 10 and 9, respectively. About 64% of the studies were open-label, crossover designs. Our assessment found that 37% of the studies had a high risk of bias, while only 6% had low risk. Food significantly affected 10 of 13 macrolides (77%) and 6 of 7 tetracyclines (86%). High positive effects on bioavailability were seen with extended-release azithromycin and clarithromycin, and erythromycin estolate. High negative impacts were observed with erythromycin propionate and stearate, azithromycin capsules, demeclocycline and omadacycline. Antacids and mineral supplements significantly decreased tetracyclines absorption. Milk and grapefruit juice showed variable impacts on absorption.

DISCUSSION

Interactions depend on antibiotics' physicochemical characteristics, intervention type, drug formulation and potential patient factors. The quality of evidence was rated low due to outdated studies, methodological diversity and unequal data availability.

[Iron supplementation in patients with chronic inflammatory bowel disease: recommendations for a practical approach]

Iron deficiency is the predominant cause of anemia. Iron deficiency anemia plays a major role, especially in patients with inflammatory bowel disease (IBD), and is the most common extraintestinal manifestation and IBD-associated systemic complication. The presence of anemia leads to a reduction in quality of life in patients with IBD associated with limitations in physical, emotional, and cognitive function. In addition, it is associated with an increased hospitalization rate. For this reason, iron supplementation is of particular importance. Oral and intravenous iron supplements are used to treat iron deficiency. Due to the lack of absorption and gastrointestinal side effects of oral substitution, intravenous supplementation is becoming increasingly important. However, there are still certain concerns about intravenous administration.With the help of this review, we want to address the topic of iron substitution in patients with IBD, summarize current guideline recommendations, and provide a practical approach.

Oral Liposomal Iron Versus Injectable Iron Sucrose for Anemia Treatment in Non-dialysis Chronic Kidney Disease Patients: A Non-inferiority Study

Introduction Anemia is a prevalent and persistent complication in chronic kidney disease (CKD), particularly in advanced stages, contributing to the deterioration of renal function and diminishing patients' quality of life. Iron supplementation constitutes a cornerstone of anemia management in this population. Among various iron formulations, liposomal iron has emerged as a promising option due to its enhanced efficacy in replenishing iron reserves and improved tolerability. Objective This study aims to assess the comparative effects of intravenous and liposomal oral iron on hemoglobin levels in non-dialysis CKD patients. Additionally, it seeks to evaluate the rate of hemoglobin correction, iron reserve status during treatment, and therapeutic tolerance to these interventions. Materials and methods A randomized controlled trial enrolled CKD patients (stages 3-5, not on dialysis) with iron deficiency anemia (hemoglobin ≤ 12 g/dL, ferritin ≤ 100 ng/mL, transferrin saturation ≤ 25%). Participants were allocated to receive either daily oral liposomal iron (Group OS) at a dosage of 30 mg or intravenous iron-hydroxide sucrose complex weekly (Group IV) for three months. Follow-up extended through the treatment phase and two months post-withdrawal. Results Thirty-one CKD patients were randomized into two groups: 14 received intravenous iron (IV group) and 17 received oral iron (OS group). After excluding four patients, the final cohort comprised 27 individuals (IV group: n=13, OS group: n=14). Both iron treatments resulted in progressive hemoglobin increases, with the IV group showing a mean increase of 14.65% (p=0.049) compared to 4.78% (p=0.003) in the OS group. Secondary analysis revealed significant increases in ferritin levels (p<0.001) and transferrin saturation (TSAT) levels (p=0.031) in the IV group. Post-treatment follow-up demonstrated stable hemoglobin levels in the OS group and a consistent increase in ferritin levels in the IV group. Adverse reactions predominantly included hypotension in the IV group (4 (30.7%)) and constipation in the OS group (4 (28.4%)). Discussion and conclusion Anemia remains a significant challenge in CKD patients. Our study compares oral liposomal iron to injectable iron for anemia treatment, aiming to minimize hospitalizations for iron infusion, preserve venous capital, and mitigate potential harmful side effects. We found oral liposomal iron to be a safe and effective option for correcting anemia in non-dialysis CKD patients, albeit with lower efficacy in replenishing iron stores compared to IV iron. Comparative analysis with similar studies supports the non-inferiority of oral liposomal iron, although IV iron retains superiority in replenishing iron reserves.

Oral iron supplementation: new formulations, old questions

Iron-deficiency anemia and pre-anemic iron deficiency are the most frequent pathologies. The first line of treatment involves oral iron supplementation. The simplest, least expensive, and most commonly prescribed drug is ferrous sulfate, while other ferrous salts and ferric complexes with polysaccharides or succinylated milk proteins are also widely used. In recent years, novel iron formulations have been developed, such as the lipophilic iron donor ferric maltol, or nanoparticle encapsulated sucrosomial® iron. Oral iron supplementation is usually efficacious in correcting iron-deficiency anemia and replenishing iron stores but causes gastrointestinal side effects that reduce compliance. When oral iron supplementation is contraindicated, intravenous iron therapy can rapidly achieve therapeutic targets without gastrointestinal complications. Herein, we critically review literature on relative efficacy and tolerability of currently available oral iron supplements, and summarize recent data on optimal dosage and frequency.

Clinical efficacy and safety of intravenous ferric carboxymaltose for treatment of restless legs syndrome: a multicenter, randomized, placebo-controlled clinical trial

STUDY OBJECTIVES

Iron therapy is associated with improvements in restless legs syndrome (RLS). This multicenter, randomized, double-blind study evaluated the effect of intravenous ferric carboxymaltose (FCM) on RLS.

METHODS

A total of 209 adult patients with a baseline International RLS (IRLS) score ≥ 15 were randomized (1:1) to FCM (750 mg/15 mL) or placebo on study days 0 and 5. Ongoing RLS medication was tapered starting on Day 5, with the goal of discontinuing treatment or achieving the lowest effective dose. Co-primary efficacy endpoints were changed from baseline in IRLS total score and the proportion of patients rated as much/very much improved on the Clinical Global Impression (CGI)-investigator (CGI-I) scale at day 42 in the "As-Treated" population.

RESULTS

The "As-Treated" population comprised 107 FCM and 101 placebo recipients; 88 (82.2%) and 68 (67.3%), respectively, completed the day 42 assessment. The IRLS score reduction was significantly greater with FCM versus placebo: least-squares mean (95% confidence interval [CI]) -8.0 (-9.5, -6.4) versus -4.8 (-6.4, -3.1); p = .0036. No significant difference was observed in the proportion of FCM (35.5%) and placebo (28.7%) recipients with a CGI-I response (odds ratio 1.37 [95% CI: 0.76, 2.47]; p = .2987). Fewer patients treated with FCM (32.7%) than placebo (59.4%) received RLS interventions between day 5 and study end (p = .0002). FCM was well tolerated.

CONCLUSIONS

The IRLS score improved with intravenous FCM versus placebo, although the combination of both co-primary endpoints was not met. Potential methodological problems in the study design are discussed.

Iron deficiency and supplementation in heart failure

Non-anaemic iron deficiency (NAID) is a strategic target in cardiovascular medicine because of its association with a range of adverse effects in various conditions. Endeavours to tackle NAID in heart failure have yielded mixed results, exposing knowledge gaps in how best to define 'iron deficiency' and the handling of iron therapies by the body. To address these gaps, we harness the latest understanding of the mechanisms of iron homeostasis outside the erythron and integrate clinical and preclinical lines of evidence. The emerging picture is that current definitions of iron deficiency do not assimilate the multiple influences at play in patients with heart failure and, consequently, fail to identify those with a truly unmet need for iron. Additionally, current iron supplementation therapies benefit only certain patients with heart failure, reflecting differences in the nature of the unmet need for iron and the modifying effects of anaemia and inflammation on the handling of iron therapies by the body. Building on these insights, we identify untapped opportunities in the management of NAID, including the refinement of current approaches and the development of novel strategies. Lessons learned from NAID in cardiovascular disease could ultimately translate into benefits for patients with other chronic conditions such as chronic kidney disease, chronic obstructive pulmonary disease and cancer.

Parenteral iron therapy in children with iron deficiency anemia

Iron deficiency anemia (IDA) continues to be a global public health problem. Oral iron is the universally accepted first-line therapy, and most children have a prompt and favorable response to oral formulations. In subsets of children who fail to respond due to intolerance, poor adherence, or inadequate intestinal absorption, parenteral iron is indicated. Despite numerous studies in adults with IDA of diverse etiologies, pediatric studies on parenteral iron use are very limited. Although mostly retrospective and small, these studies have documented the efficacy and safety profile of intravenous iron formulations. In this editorial the author comments on the most important published data and underscores the need to seriously consider parenteral iron use in children unresponsive to oral therapy.

Iron-carbohydrate complexes treating iron anaemia: Understanding the nano-structure and interactions with proteins through orthogonal characterisation

Intravenous (IV) iron-carbohydrate complexes are widely used nanoparticles (NPs) to treat iron deficiency anaemia, often associated with medical conditions such as chronic kidney disease, heart failure and various inflammatory conditions. Even though a plethora of physicochemical characterisation data and clinical studies are available for these products, evidence-based correlation between physicochemical properties of iron-carbohydrate complexes and clinical outcome has not fully been elucidated yet. Studies on other metal oxide NPs suggest that early interactions between NPs and blood upon IV injection are key to understanding how differences in physicochemical characteristics of iron-carbohydrate complexes cause variance in clinical outcomes. We therefore investigated the core-ligand structure of two clinically relevant iron-carbohydrate complexes, iron sucrose (IS) and ferric carboxymaltose (FCM), and their interactions with two structurally different human plasma proteins, human serum albumin (HSA) and fibrinogen, using a combination of cryo-scanning transmission electron microscopy (cryo-STEM), x-ray diffraction (XRD), small-angle x-ray scattering (SAXS) and small-angle neutron scattering (SANS). Using this orthogonal approach, we defined the nano-structure, individual building blocks and surface morphology for IS and FCM. Importantly, we revealed significant differences in the surface morphology of the iron-carbohydrate complexes. FCM shows a localised carbohydrate shell around its core, in contrast to IS, which is characterised by a diffuse and dynamic layer of carbohydrate ligand surrounding its core. We hypothesised that such differences in carbohydrate morphology determine the interaction between iron-carbohydrate complexes and proteins and therefore investigated the NPs in the presence of HSA and fibrinogen. Intriguingly, IS showed significant interaction with HSA and fibrinogen, forming NP-protein clusters, while FCM only showed significant interaction with fibrinogen. We postulate that these differences could influence bio-response of the two formulations and their clinical outcome. In conclusion, our study provides orthogonal characterisation of two clinically relevant iron-carbohydrate complexes and first hints at their interaction behaviour with proteins in the human bloodstream, setting a prerequisite towards complete understanding of the correlation between physicochemical properties and clinical outcome.

A meta-analysis of ferric carboxymaltose versus other intravenous iron preparations for the management of iron deficiency anemia during pregnancy

Objective

We conducted a meta-analysis of randomized clinical trials evaluating the clinical effects of ferric carboxymaltose therapy compared to other intravenous iron in improving hemoglobin and serum ferritin in pregnant women. We also assessed the safety of ferric carboxymaltose vs. other intravenous iron.

Data source

EMBASE, PubMed, and Web of Science were searched for trials related to ferric carboxymaltose in pregnant women, published between 2005 and 2021. We also reviewed articles from google scholar. The keywords "ferric carboxymaltose," "FCM," "intravenous," "randomized," "pregnancy," "quality of life," and "neonatal outcomes" were used to search the literature. The search was limited to pregnant women.

Selection of studies

Studies related to ferric carboxymaltose in pregnancy were scanned. Observational studies, review articles, and case reports were excluded. Randomized studies in pregnant women involving ferric carboxymaltose and other intravenous iron formulations were shortlisted. Of 256 studies, nine randomized control trials were selected.

Data collection

Two reviewers independently extracted data from nine selected trials.

Data synthesis

The final effect size for increase in hemoglobin after treatment was significant for ferric carboxymaltose vs. iron sucrose/iron polymaltose (standard mean difference 0.89g/dl [95% confidence interval 0.27,1.51]). The final effect size for the increase in ferritin after treatment was more for ferric carboxymaltose vs. iron sucrose/iron polymaltose (standard mean difference 22.53µg/L [-7.26, 52.33]). No serious adverse events were reported with ferric carboxymaltose or other intravenous iron.

Conclusion

Ferric carboxymaltose demonstrated better efficacy than other intravenous iron in increasing hemoglobin and ferritin levels in treating iron deficiency anemia in pregnant women.

IV iron formulations and use in adults

Intravenous iron has become a major component of the therapeutic armamentarium for iron deficiency and iron deficiency anemia. The earliest formulations were associated with unacceptable toxicity. Newer formulations, with complex carbohydrate cores that bind elemental iron more tightly, allow the administration of full therapeutic doses in 15 to 60 minutes. Nonetheless, a folklore of danger, fueled by earlier formulations no longer available, continues to foment caution. Complement-mediated minor infusion reactions, referred to as complement activation-related pseudo-allergy, resolve without therapy. Inappropriate intervention with vasopressors and H1 blockers converts these minor reactions into hemodynamically significant adverse events. Four new formulations, low-molecular-weight iron dextran, ferumoxytol, ferric carboxymaltose, and ferric derisomaltose, all approved for the treatment of iron deficiency in a host of conditions, are now widely used with an excellent safety profile. Herein, the administration, safety, indications, and management of infusion reactions are discussed. Treatment-emergent hypophosphatemia, a newly recognized side effect for some formulations, is also reviewed. Based on the preponderance of published evidence, intravenous iron should be moved up-front for the treatment of iron deficiency and iron deficiency anemia in those conditions in which oral iron is suboptimal.

Animal models of kidney iron overload and ferroptosis: a review of the literature

In recent years, it has been identified that excess iron contributes to the development of various pathologies and their complications. Kidney diseases do not escape the toxic effects of iron, and ferroptosis is identified as a pathophysiological mechanism that could be a therapeutic target to avoid damage or progression of kidney disease. Ferroptosis is cell death associated with iron-dependent oxidative stress. To study the effects of iron overload (IOL) in the kidney, numerous animal models have been developed. The methodological differences between these models should reflect the IOL-generating mechanisms associated with human IOL diseases. A careful choice of animal model should be considered for translational purposes.

Safety, pharmacokinetics, and pharmacodynamics of intravenous ferric carboxymaltose in children with iron deficiency anemia

BACKGROUND

Iron deficiency is the primary cause of anemia in children. Intravenous (IV) iron formulations circumvent malabsorption and rapidly restore hemoglobin.

METHODS

This Phase 2, non-randomized, multicenter study characterized the safety profile and determined appropriate dosing of ferric carboxymaltose (FCM) in children with iron deficiency anemia. Patients aged 1-17 years with hemoglobin <11 g/dL and transferrin saturation <20% received single IV doses of undiluted FCM 7.5 mg/kg (n = 16) or 15 mg/kg (n = 19).

RESULTS

The most common drug-related treatment-emergent adverse event was urticaria (in three recipients of FCM 15 mg/kg). Systemic exposure to iron increased in a dose-proportional manner with approximate doubling of mean baseline-corrected maximum serum iron concentration (157 µg/mL with FCM 7.5 mg/kg; and 310 µg/mL with FCM 15 mg/kg) and area under the serum concentration-time curve (1901 and 4851 h·µg/mL, respectively). Baseline hemoglobin was 9.2 and 9.5 g/dL in the FCM 7.5 and 15 mg/kg groups, respectively, with mean maximum changes in hemoglobin of 2.2 and 3.0 g/dL, respectively.

CONCLUSIONS

In conclusion, FCM was well tolerated by pediatric patients. Improvements in hemoglobin were greater with the higher dose, supporting use of the FCM 15 mg/kg dose in pediatric patients (Clinicaltrials.gov NCT02410213).

IMPACT

This study provided information on the pharmacokinetics and safety of intravenous ferric carboxymaltose for treatment of iron deficiency anemia in children and adolescents. In children aged 1-17 years with iron deficiency anemia, single intravenous doses of ferric carboxymaltose 7.5 or 15 mg/kg increased systemic exposure to iron in a dose-proportional manner, with clinically meaningful increases in hemoglobin. The most common drug-related treatment-emergent adverse event was urticaria. The findings suggest that iron deficiency anemia in children can be corrected with a single intravenous dose of ferric carboxymaltose and support use of a 15 mg/kg dose.

Uncovering the dynamics of cellular responses induced by iron-carbohydrate complexes in human macrophages using quantitative proteomics and phosphoproteomics

Iron-carbohydrate complexes are widely used to treat iron deficiencies. Macrophages play a crucial role in the uptake and fate of these nanomedicines, however, how complexed iron carbohydrates are taken up and metabolized by macrophages is still not fully understood. Using a (phospho-)proteomics approach, we assessed differences in protein expression and phosphorylation in M2 macrophages triggered by iron sucrose (IS). Our results show that IS alters the expression of multiple receptors, indicative of a complex entry mechanism. Besides, IS induced an increase in intracellular ferritin, the loss of M2 polarization, protective mechanisms against ferroptosis, and an autophagic response. These data indicate that macrophages can use IS as a source of iron for its storage and later release, however, the excess of iron can cause oxidative stress, which can be successfully regulated by the cells. When comparing IS with ferric carboxymaltose (FCM) and iron isomaltoside-1000 (IIM), complexes with a higher carbohydrate ligand stability, we observed that FCM and IIM are metabolized at a slower rate, and trigger M2 polarization loss to a lower extent. These results indicate that the surface characteristics of the iron-carbohydrate complexes may influence the cell responses. Our data show that the application of (phospho-)proteomics can lead to a better understanding of metabolic processes, including the uptake, biodegradation and bioavailability of nanomedicines.

Efficacy and Safety of Intravenous Ferric Carboxymaltose Treatment of Iron Deficiency Anaemia in Patients with Corpus Atrophic Gastritis: A Retrospective Study

Corpus Atrophic Gastritis (CAG) is characterised by iron malabsorption leading to iron deficiency anaemia (IDA), which rarely responds to oral therapy. Ferric carboxymaltose (FCM), shown to be a safe and effective intravenous iron therapy in other diseases, has not been investigated yet in CAG. Thus, we aimed to assess the safety and efficacy of FCM in CAG-related IDA. A retrospective study on 91 patients identified CAG as the only cause of IDA treated with FCM. Twenty-three were excluded for incomplete follow-up. Sixty-eight were evaluated for safety and efficacy, while three were evaluated for safety only due to infusion interruption for side effects. Haemoglobin and iron storage were evaluated pre-infusion (T0), at 4 weeks (T4) and 12 weeks (T12) after infusion. An eventual IDA relapse was analysed. Two cases reported mild side effects. Haemoglobin significantly increased at T4, and T12, reaching +3.1 g/dL. Ferritin increased at T4, decreasing at T12, while transferrin saturation increased progressively until reaching a plateau. IDA relapsed in 55.4% of patients at a mean of 24.6 months. The only factor associated with relapse was female gender [OR (95% CI): 6.6 (1.5-28.6)]. FCM proved to be safe and effective in treating CAG-related IDA, ensuring quick and long-lasting recovery.

Iron deficiency and sexual dysfunction in women

INTRODUCTION

Sexual dysfunction negatively affects approximately 40% to 50% of adult women across various stages of life. Common risk factors include sexual traumas, relationship problems, chronic conditions, medication side effects, and poor physical health, including iron deficiency.

OBJECTIVES

This review summarizes a presentation from a symposium that discussed the types and causes of sexual dysfunction at key times in women's lives, focusing on the relationship between iron deficiency and sexual dysfunction.

METHODS

The symposium was held at the XV Annual European Urogynaecological Association Congress, Antibes, France, in October 2022. Symposium content was identified through literature searches of PubMed. Original research, review articles, and Cochrane analyses discussing sexual dysfunction in association with iron deficiency/anemia were included.

RESULTS

Iron deficiency in women is commonly caused by abnormal uterine bleeding, but women may develop iron deficiency anemia (IDA) because of increased iron needs or reduced iron intake/absorption. Treatment with oral iron supplementation has been shown to improve sexual function in women with IDA. Ferrous sulphate is considered as a standard of care for oral iron treatment; prolonged-release iron formulations have improved tolerability, enabling lower doses and better tolerability.

CONCLUSION

IDA and sexual dysfunction are related, so the identification of sexual dysfunction or iron deficiency in a woman should prompt an investigation of the other condition. Testing for iron deficiency is an inexpensive and simple step that can be routinely included in the workup of women with sexual dysfunction. Once identified, IDA and sexual dysfunction in women should be treated and followed to optimize quality of life.

Treatment of Iron Deficiency in Heart Failure

PURPOSE OF REVIEW

Heart failure (HF) is commonly associated with iron deficiency (ID), defined as insufficient levels of iron to meet physiological demands. ID's association with anaemia is well understood but it is increasingly recognised as an important comorbidity in HF, even in the absence of anaemia. This review summarises contemporary evidence for the measurement and treatment of ID, in both HFrEF and HFpEF, and specific HF aetiologies, and highlights important gaps in the evidence-base.

RECENT FINDINGS

ID is common among patients with HF and associated with increased morbidity and mortality. Correcting ID in patients with HF can impact upon functional status, exercise tolerance, symptoms, and overall quality of life, irrespective of anaemia status. ID is a modifiable comorbidity in HF. Therefore, recognising and treating ID has emerging therapeutic potential and is important for all clinicians who care for patients with HF to understand the rationale and approach to treatment.

Putting square pegs in round holes: why traditional pharmacokinetic principles cannot universally be applied to iron-carbohydrate complexes

Intravenous iron-carbohydrate complexes are nanomedicines that are commonly used to treat iron deficiency and iron deficiency anemia of various etiologies. Many challenges remain regarding these complex drugs in the context of fully understanding their pharmacokinetic parameters. Firstly, the measurement of the intact iron nanoparticles versus endogenous iron concentration fundamentally limits the availability of data for computational modeling. Secondly, the models need to include several parameters to describe the iron metabolism which is not completely defined and those identified (e.g. ferritin) exhibit considerable interpatient variability. Additionally, modeling is further complicated by the lack of traditional receptor/enzyme interactions. The known parameters of bioavailability, distribution, metabolism, and excretion for iron-carbohydrate nanomedicines will be reviewed and future challenges that currently prevent the direct application of physiologically-based pharmacokinetic or other computational modeling techniques will be discussed.

Ferric carboxymaltose for anemia in Crohn’s disease patients at a tertiary center: A retrospective observational cohort study

BACKGROUND

Although the gastrointestinal tract is the most affected by Crohn’s disease (CD), the condition triggers other consequent manifestations, and iron deficiency anemia (IDA) is one of the most common. Intravenous (IV) iron replacement is currently available through several drugs, such as ferric hydroxide sucrose and ferric carboxymaltose (FCM). However, the clinical management of these conditions can be challenging.

AIM

To elucidate the drug’s effectiveness, the present study analyzed, through medical records, the clinical and epidemiological data of a cohort of patients with active CD who received IV FCM for the IDA treatment.

METHODS

This retrospective observational study included 25 patients with active CD, severe anemia, and refractory to previous conventional treatments. Patients were evaluated two times: During the last treatment with ferric hydroxide sucrose and treatment with FCM.

RESULTS

After treatment with FCM, parameters of IDA assessment significantly improved, serum hemoglobin (Hb) levels increased in 93% of patients (P < 0.0001), and in 44%, there was an increase of ≥ 2 g/dL in a single application. In addition, 86% of the patients showed an increase in serum iron (P < 0.0001) and ferritin (P = 0.0008) and 50% in transferrin saturation (P = 0.01). The serum iron levels at baseline showed a negative association with the ileal and colonic CD and use of biologics and a positive association with patients who developed CD later in life after the age of 40 (A3) and with a stenosing (B2) and fistulizing (B3) phenotype. The values of Hb and hematocrit after ferric hydroxide sucrose treatment remained similar to those found before treatment.

CONCLUSION

This study demonstrated that FCM is an important therapeutic strategy for treating IDA in CD patients, achieving satisfactory results in refractory cases.

Recommendations From the International Consensus Conference on Anemia Management in Surgical Patients (ICCAMS)

BACKGROUND

Perioperative anemia has been associated with increased risk of red blood cell transfusion and increased morbidity and mortality after surgery. The optimal approach to the diagnosis and management of perioperative anemia is not fully established.

OBJECTIVE

To develop consensus recommendations for anemia management in surgical patients.

METHODS

An international expert panel reviewed the current evidence and developed recommendations using modified RAND Delphi methodology.

RESULTS

The panel recommends that all patients except those undergoing minor procedures be screened for anemia before surgery. Appropriate therapy for anemia should be guided by an accurate diagnosis of the etiology. The need to proceed with surgery in some patients with anemia is expected to persist. However, early identification and effective treatment of anemia has the potential to reduce the risks associated with surgery and improve clinical outcomes. As with preoperative anemia, postoperative anemia should be treated in the perioperative period.

CONCLUSIONS

Early identification and effective treatment of anemia has the potential to improve clinical outcomes in surgical patients.

Perioperative Tracking of Intravenous Iron in Patients Undergoing On-Pump Cardiac Surgery: A Prospective, Single-Center Pilot Trial

BACKGROUND

Preoperative intravenous iron administration is a frequently used patient blood management procedure. If the timeframe of intravenous iron administration before surgery is short, (1) the concentration of the intravenous iron compound might still be high in patients' plasma when undergoing surgery and (2) this iron in patients' plasma is at risk to be lost due to blood loss. The aim of the current study was, therefore, to track the iron compound ferric carboxymaltose (FCM) before, during, and after cardiac surgery requiring cardiopulmonary bypass, with an emphasis on intraoperative iron losses in shed blood and potential recovery through autologous cell salvage.

METHODS

Concentrations of FCM were analyzed in patients' blood using a hyphenation of liquid chromatography and inductively coupled plasma-mass spectrometry to distinguish between pharmaceutical compound FCM and serum iron. In this prospective, single-center pilot trial, 13 anemic and 10 control patients were included. Anemic patients with hemoglobin levels ≤12/13 g/dL in women and men were treated with 500 milligrams (mg) intravenous FCM 12 to 96 hours before elective on-pump cardiac surgery. Patients' blood samples were collected before surgery and at days 0, 1, 3, and 7 after surgery. One sample each was taken of the cardiopulmonary bypass, the autologous red blood cell concentrate generated by cell salvage, and the cell salvage disposal bag.

RESULTS

Patients who had received FCM <48 hours before surgery had higher FCM serum levels (median [Q1-Q3], 52.9 [13.0-91.6]) compared to ≥48 hours (2.1 [0.7-5.1] µg/mL, P = .008). Of 500-mg FCM administered <48 hours, 327.37 (257.96-402.48) mg were incorporated compared to administration ≥48 hours with 493.60 (487.78-496.70) mg. After surgery, patients' plasma FCM concentration in the FCM <48 hours group was decreased (-27.1 [-30 to -5.9] µg/mL). Little FCM was found in the cell salvage disposal bag (<48 hours, 4.2 [3.0-25.8] µg/mL, equivalent to 29.0 [19.0-40.7] mg total; equivalent to 5.8% or 1/17th of the 500 mg FCM initially administered), almost none in the autologous red blood cell concentrate (<48 hours, 0.1 [0.0-0.43] µg/mL).

CONCLUSIONS

The data generate the hypotheses that nearly all FCM is incorporated into iron stores with administration ≥48 hours before surgery. When FCM is given <48 hours of surgery, the majority is incorporated into iron stores by the time of surgery, although a small amount may be lost during surgical bleeding with limited recovery by cell salvage.

The clinical relevance of detectable plasma iron species in iron overload states and subsequent to intravenous iron-carbohydrate administration

Many disorders of iron homeostasis (e.g., iron overload) are associated with the dynamic kinetic profiles of multiple non-transferrin bound iron (NTBI) species, chronic exposure to which is associated with deleterious end-organ effects. Here we discuss the chemical nature of NTBI species, challenges with measuring NTBI in plasma, and the clinical relevance of NTBI exposure based on source (iron overload disorder vs. intravenous iron-carbohydrate complex administration). NTBI is not a single entity but consists of multiple, often poorly characterized species, some of which are kinetically non-exchangeable while others are relatively exchangeable. Prolonged presence of plasma NTBI is associated with excessive tissue iron accumulation in susceptible tissues, with consequences, such as endocrinopathy and heart failure. In contrast, intravenous iron-carbohydrate nanomedicines administration leads only to transient NTBI appearance and lacks evidence for association with adverse clinical outcomes. Assays to measure plasma NTBI are typically technically complex and remain chiefly a research tool. There have been two general approaches to estimating NTBI: capture assays and redox-activity assays. Early assays could not avoid capturing some iron from transferrin, thus overestimating NTBI. By contrast, some later assays may have promoted the donation of NTBI species to transferrin during the assay procedure, potentially underestimating NTBI levels. The levels of transferrin saturation at which NTBI species have been detectable have varied between different methodologies and between patient populations studied.

International Delphi consensus guidelines for follow-up after prophylactic total gastrectomy: the Life after Prophylactic Total Gastrectomy (LAP-TG) study

BACKGROUND

Prophylactic total gastrectomy (PTG) remains the only means of preventing gastric cancer for people with genetic mutations predisposing to Hereditary Diffuse Gastric Cancer (HDGC), mainly in the CDH1 gene. The small but growing cohort of people undergoing PTG at a young age are expected to have a life-expectancy close to the general population, however, knowledge of the long-term effects of, and monitoring requirements after, PTG is limited. This study aims to define the standard of care for follow-up after PTG.

METHODS

Through a combination of literature review and two-round Delphi consensus of major HDGC/PTG units and physicians, and patient advocates, we produced a set of recommendations for follow-up after PTG.

RESULTS

There were 42 first round, and 62 second round, responses from clinicians, allied health professionals and patient advocates. The guidelines include recommendations for timing of assessments and specialties involved in providing follow-up, micronutrient supplementation and monitoring, bone health and the provision of written information.

CONCLUSION

While the evidence supporting the guidelines is limited, expert consensus provides a framework to best manage people following PTG, and could support the collection of information on the long-term effects of PTG.

Iron deficiency and soil-transmitted helminth infection: classic and neglected connections

Beyond participating in the oxygen transport by red blood cells, iron is an essential micronutrient and contributes to different physiological pathways and processes, such as cell proliferation, DNA repair, and other homeostatic functions. Iron deficiency affects millions of people, especially children and pregnant women. The consequences of iron deficiency are diverse, including inadequate child development, impaired cognition, and reduced productivity. Several factors contribute to iron deficiency, such as iron-poor diet, genetic factors, and infection with soil-transmitted helminths (STHs), especially roundworms (Ascaris lumbricoides), hookworms (Necator americanus and Ancylostoma duodenale), and whipworms (Trichuris trichiura). This review updates and summarizes the role of STHs as drivers of iron deficiency. Also, the poorly explored connections between STH infection, geophagia (a pica manifestation), immune response, and iron deficiency are discussed, highlighting how iron deficiency may act as a risk factor for infections by STHs, in addition to being a consequence of intestinal parasitic infections. Finally, strategies for control and management of iron deficiency and STH infection are described.

Beneficios del uso del hierro parenteral como alternativa eficaz en el manejo de la anemia gestacional en Colombia

Introducción. La Organización Mundial de la Salud (OMS) estima que más del 40% de las mujeres embarazadas a nivel mundial tienen anemia, y la mitad de estas padecen deficiencia de hierro. La prevalencia en América Latina es del 40% y en Colombia del 44.7%. Fisiológicamente en el embarazo se produce una mal llamada “anemia dilucional”, existen condiciones en la embarazada que la predisponen a tener una anemia patológica. Esta última es causada principalmente por un déficit de hierro, de allí la importancia de diagnosticar a tiempo esta entidad e iniciar el manejo. La administración de hierro es la base del tratamiento de la anemia por deficiencia de hierro. Puede ser administrado por vía oral, la cual es la preferida en la mayoría de las pacientes; sin embargo, cuando este no es posible administrarlo, es esencial recurrir al hierro parenteral. No obstante, el hierro parenteral es poco usado como primera línea en el manejo de la anemia gestacional. El presente artículo tiene como objetivo realizar una revisión que permita identificar la terapia con hierro parenteral como una alternativa eficaz de manejo para la anemia gestacional, teniendo en cuenta las características farmacológicas, la administración y el uso entre las diferentes moléculas disponibles en Colombia. Metodología. Corresponde a un estudio de revisión de literatura en bases de datos y bibliotecas electrónicas, los criterios que se tuvieron en cuenta fueron textos publicados entre 1996 y 2020, en español e inglés. Se obtuvo un resultado de 95 artículos, de los cuales se seleccionaron 49. Las palabras clave para su búsqueda fueron fisiología, hierro parenteral, anemia gestacional, déficit de hierro, complicaciones del embarazo, compuestos de hierro, farmacocinética, diagnóstico y tratamiento. División de temas tratados. Fisiología; ayudas diagnósticas; características farmacológicas del hierro parenteral; ventajas, indicaciones y contraindicaciones del hierro parenteral; efectos secundarios y forma de aplicación. Conclusiones. El hierro parenteral es un tratamiento seguro y eficaz para manejar la anemia en el embarazo, se debe tener en cuenta las indicaciones y la farmacología de las moléculas para elegir la más adecuada. Además, repone más rápidamente las reservas de hierro y los niveles de hemoglobina.

Efficacy, Safety and Pharmacoeconomic Analysis of Intravenous Ferric Carboxymaltose in Anemic Hemodialysis Patients Unresponsive to Ferric Gluconate Treatment: A Multicenter Retrospective Study

Patients undergoing hemodialysis with iron deficiency anemia (IDA) receiving treatment with erythropoiesis-stimulating agents (ESAs) who were intolerant or non-responsive to intravenous (i.v.) ferric gluconate (FG) (hemoglobin; Hb values < 10.5 g/dL or increase in <1 g/dL) or % transferrin saturation; TSAT of <20%) in the previous 6 months were switched to i.v. ferric carboxymaltose (FCM). Changes in iron status parameters, economic and safety measures were also assessed. Seventy-seven hemodialysis patients aged 68 ± 15 years were included. Erythropoietin resistance index decreased from 24.2 ± 14.6 at pre-switch to 20.4 ± 14.6 after 6 months of FCM treatment and Hb levels ≥10.5 g/dL improved from 61% to 75.3% patients (p = 0.042). A 1 g/dL increase in Hb levels was also seen in 26% of patients as well as a 37.7% increase in patients achieving >20% increase in TSAT after FCM. Levels of Hb, TSAT and ferritin parameters increased during FCM treatment with a concomitant decrease in ESA. A mixed-model analysis, which also considered gender, confirmed these trends. Safety variables remained stable, no hypersensitivity reaction was recorded and only one patient reported an adverse event after FCM. FCM treatment was associated with a cost saving of 11.11 EUR/patient/month. These results confirm the efficacy, safety and cost-effectiveness of FCM in correcting IDA in hemodialysis patients.

Impaired pancreatic beta-cell function after a single dose of oral iron: a before-and-after (pre-post) study

INTRODUCTION

Although in vitro and animal studies have shown that iron loading in pancreatic beta-cells impaired insulin secretion, no human studies have documented the acute effects of oral iron on beta-cell insulin secretory capacity. In this study, we determined beta-cell insulin secretory capacity at baseline and after a single oral dose of iron (ferrous sulphate, 120 mg elemental iron) in healthy male individuals.

METHODS

Fifteen healthy male volunteers underwent an oral glucose tolerance test (OGTT) to document baseline glucose tolerance and insulin secretion kinetics (baseline OGTT). One week later, the same subjects underwent a second OGTT, two hours after an oral dose of ferrous sulfate (120 mg of elemental iron) (post-iron OGTT). Changes in disposition index, insulin secretion kinetics, glucose tolerance, insulin resistance, insulin clearance, and iron-related parameters in serum were determined.

RESULTS

Compared to baseline OGTT, the areas under the curve (AUC) for serum iron and transferrin saturation increased by 125% and 118% respectively, in the post-iron OGTT. The disposition index decreased by 20% (p=0.009) and the AUC for glucose concentrations increased by 5.7% (p<0.001) during the post-iron OGTT. The insulin secretion rate was marginally lower during the first hour (-3.5%, p=0.63), but became significantly higher during the second hour (22%, p=0.005) of the post-iron OGTT. Insulin resistance and insulin clearance rate were not affected by iron intake.

CONCLUSION

The decrease in disposition index and glucose tolerance observed after the oral dose of iron points to an acute iron-induced impairment in pancreatic beta-cell insulin secretory capacity. This article is protected by copyright. All rights reserved.

Tissue biodistribution of intravenous iron-carbohydrate nanomedicines differs between preparations with varying physicochemical characteristics in an anemic rat model

Intravenously administered iron-carbohydrate preparations are a structurally heterogenous class of nanomedicines. Iron biodistribution to target tissues is greatly affected by the physicochemical characteristics of these nanoparticles. Some regulatory agencies have recommended performing studies in animal models for biodistribution characterization and bioequivalence evaluation. In the present work, a systematic comparison of iron exposure, tissue biodistribution and pharmacodynamics of four intravenous iron-carbohydrates in anemic CD rats was conducted. A pilot study was performed to establish the anemic rat model, followed by a control study to evaluate the pharmacokinetics (serum iron, biodistribution) and pharmacodynamics (hematological parameters) in healthy and anemic controls and anemic rats receiving ferric carboxymaltose (FCM). The same parameters were then evaluated in a comparative study in anemic rats receiving FCM, iron sucrose (IS), iron isomaltoside 1000 (IIM), and iron dextran (ID). Despite similar serum iron profiles observed across the investigated nanomedicines, tissue iron biodistribution varied markedly between the individual intravenous iron-carbohydrate complexes. Tissue iron repletion differences were also confirmed by histopathology. These results suggest that employing serum iron profiles as a surrogate for tissue biodistribution may be erroneous. The variability observed in tissue biodistribution may indicate different pharmacodynamic profiles and warrants further study.

Kupffer Cells and Blood Monocytes Orchestrate the Clearance of Iron-Carbohydrate Nanoparticles from Serum

Intravenous (IV) iron nanoparticle preparations are widely used to treat iron deficiency. The mechanism of mononuclear phagocyte system-mediated clearance of IV iron nanoparticles is unknown. The early uptake and homeostasis of iron after injection of ferric carboxymaltose (FCM) in mice was studied. An increase in serum iron was observed at 2.5 h followed by a return to baseline by 24 h. An increase in circulating monocytes was observed, particularly Ly6C^hi and Ly6C^low. FCM was also associated with a time-dependent decrease in liver Kupffer cells (KCs) and increase in liver monocytes. The increase in liver monocytes suggests an influx of iron-rich blood monocytes, while some KCs underwent apoptosis. Adoptive transfer experiments demonstrated that following liver infiltration, blood monocytes differentiated to KCs. KCs were also critical for IV iron uptake and biodegradation. Indeed, anti-Colony Stimulating Factor 1 Receptor (CSF1R)-mediated depletion of KCs resulted in elevated serum iron levels and impaired iron uptake by the liver. Gene expression profiling indicated that C-C chemokine receptor type 5 (CCR5) might be involved in monocyte recruitment to the liver, confirmed by pharmaceutical inhibition of CCR5. Liver KCs play a pivotal role in the clearance and storage of IV iron and KCs appear to be supported by the expanded blood monocyte population.

Criticality of Surface Characteristics of Intravenous Iron-Carbohydrate Nanoparticle Complexes: Implications for Pharmacokinetics and Pharmacodynamics

Un-complexed polynuclear ferric oxyhydroxide cannot be administered safely or effectively to patients. When polynuclear iron cores are formed with carbohydrates of various structures, stable complexes with surface carbohydrates driven by multiple interacting sites and forces are formed. These complexes deliver iron in a usable form to the body while avoiding the serious adverse effects of un-complexed forms of iron, such as polynuclear ferric oxyhydroxide. The rate and extent of plasma clearance and tissue biodistribution is variable among the commercially available iron–carbohydrate complexes and is driven principally by the surface characteristics of the complexes which dictate macrophage opsonization. The surface chemistry differences between the iron–carbohydrate complexes results in significant differences in in vivo pharmacokinetic and pharmacodynamic profiles as well as adverse event profiles, demonstrating that the entire iron–carbohydrate complex furnishes the pharmacologic action for these complex products. Currently available physicochemical characterization methods have limitations in biorelevant matrices resulting in challenges in defining critical quality attributes for surface characteristics for this class of complex nanomedicines.

Need for Expansion of Pharmacy Education Globally for the Growing Field of Nanomedicine

The emerging landscape of nanomedicine includes a wide variety of active pharmaceutical ingredients and drug formulations. Their design provides nanomedicines with unique features leading to improved pharmacokinetics and pharmacodynamics. They are manufactured using conventional or biotechnological manufacturing processes. Their physical characteristics are vastly different from traditional small-molecule drugs. Pharmacists are important members of the multi-disciplinary team of scientists involved in their development and clinical application. Consequently, their training should lead to an understanding of the complexities associated with the production and evaluation of nanomedicines. Therefore, student pharmacists, post-doctoral researchers, and trainees should be given more exposure to this rapidly evolving class of therapeutics. This commentary will provide an overview of nanomedicine education within the selection of pharmacy programs globally, discuss the current regulatory challenges, and describe different approaches to incorporate nanomedicine science in pharmacy programs around the world.

Abnormal whole-body energy metabolism in iron-deficient humans despite preserved skeletal muscle oxidative phosphorylation

Iron deficiency impairs skeletal muscle metabolism. The underlying mechanisms are incompletely characterised, but animal and human experiments suggest the involvement of signalling pathways co-dependent upon oxygen and iron availability, including the pathway associated with hypoxia-inducible factor (HIF). We performed a prospective, case-control, clinical physiology study to explore the effects of iron deficiency on human metabolism, using exercise as a stressor. Thirteen iron-deficient (ID) individuals and thirteen iron-replete (IR) control participants each underwent 31P-magnetic resonance spectroscopy of exercising calf muscle to investigate differences in oxidative phosphorylation, followed by whole-body cardiopulmonary exercise testing. Thereafter, individuals were given an intravenous (IV) infusion, randomised to either iron or saline, and the assessments repeated ~ 1 week later. Neither baseline iron status nor IV iron significantly influenced high-energy phosphate metabolism. During submaximal cardiopulmonary exercise, the rate of decline in blood lactate concentration was diminished in the ID group (P = 0.005). Intravenous iron corrected this abnormality. Furthermore, IV iron increased lactate threshold during maximal cardiopulmonary exercise by ~ 10%, regardless of baseline iron status. These findings demonstrate abnormal whole-body energy metabolism in iron-deficient but otherwise healthy humans. Iron deficiency promotes a more glycolytic phenotype without having a detectable effect on mitochondrial bioenergetics.

Iron Deficiency in Heart Failure: Mechanisms and Pathophysiology

Iron is an essential micronutrient for a myriad of physiological processes in the body beyond erythropoiesis. Iron deficiency (ID) is a common comorbidity in patients with heart failure (HF), with a prevalence reaching up to 59% even in non-anaemic patients. ID impairs exercise capacity, reduces the quality of life, increases hospitalisation rate and mortality risk regardless of anaemia. Intravenously correcting ID has emerged as a promising treatment in HF as it has been shown to alleviate symptoms, improve quality of life and exercise capacity and reduce hospitalisations. However, the pathophysiology of ID in HF remains poorly characterised. Recognition of ID in HF triggered more research with the aim to explain how correcting ID improves HF status as well as the underlying causes of ID in the first place. In the past few years, significant progress has been made in understanding iron homeostasis by characterising the role of the iron-regulating hormone hepcidin, the effects of ID on skeletal and cardiac myocytes, kidneys and the immune system. In this review, we summarise the current knowledge and recent advances in the pathophysiology of ID in heart failure, the deleterious systemic and cellular consequences of ID.

Comparison of efficacy & safety of iron polymaltose complex & ferrous ascorbate with ferrous sulphate in pregnant women with iron-deficiency anaemia

Background & objectives

Iron-deficiency anaemia (IDA) is a common nutritional deficiency among pregnant women in India. It has a significant impact on the health of the mother as well as that of the foetus. IDA generally responds well to treatment with oral iron supplementation. However, oral iron supplements are toxic to the gastrointestinal mucosa and intolerance is common, resulting in poor compliance and failure of treatment. The iron salts such as iron hydroxide polymaltose complex (IPC) and ferrous ascorbate (FeA) are claimed to have low gastrointestinal intolerance, therefore better patient compliance than the conventionally used ferrous sulphate (FS). These preparations also claim to increase haemoglobin level faster as well as improve the iron storage better than FS. This study was done to compare the efficacy and safety of FS with IPC and FeA.

Methods

It was a randomized, parallel, open label, study among pregnant women of gestational age between 12 to 26 wk with moderate anaemia. Patients were randomly allocated to receive either FS, IPC or FeA. They were then followed up for 90 days to observe for improvement in the haemoglobin levels and other haematological parameters or any adverse drug reaction.

Results

The haemoglobin levels were comparable in the three groups except at day 90 when FeA group had significantly higher haemoglobin level as compared to FS group (P<0.05). The overall adverse effect profiles were also comparable among the study groups except epigastric pain which was more commonly reported in the FS group.

Interpretation & conclusions

The results of the study showed that FS, IPC and FeA have comparable efficacy and safety profile in the treatment of IDA of pregnancy.

Comparison of Iron Dosing Strategies in Patients Undergoing Long-Term Hemodialysis: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

Whether iron supplementation in patients on hemodialysis could be delivered by less frequent but higher single doses compared with the currently more common higher-frequency schedules of lower single iron doses is unknown.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We carried out an open-label, randomized, controlled noninferiority trial over 40 weeks in patients on prevalent hemodialysis (n=142). We administered in total 2 g iron as 100 mg iron sucrose biweekly in a continuous (20 × 100 mg) fashion or 500 mg ferric carboxymaltose every 10 weeks in a periodic (4 × 500 mg) fashion. The primary end point was the change in hemoglobin at week 40 from baseline with a noninferiority margin of -0.8 g/dl. Secondary end points were changes in ferritin, transferrin, transferrin saturation, and erythropoiesis-stimulating agent use.

RESULTS

In total, 108 patients completed the study. At 40 weeks, hemoglobin changed by -0.27 g/dl (95% confidence interval, -0.64 to 0.09) in the iron sucrose arm and by -0.74 g/dl (95% confidence interval, -1.1 to -0.39) in the ferric carboxymaltose arm compared with baseline. Noninferiority was not established in the per-protocol population as hemoglobin changes compared with baseline differed by -0.47 g/dl (95% confidence interval, -0.95 to 0.01) in the ferric carboxymaltose arm compared with the iron sucrose arm. Proportional changes from baseline to week 40 differed by -31% (98.3% confidence interval, -52 to -0.1) for ferritin, by 1% (98.3% confidence interval, -7 to 10) for transferrin, and by -27% (98.3% confidence interval, -39 to -13) for transferrin saturation in the ferric carboxymaltose arm compared with the iron sucrose arm. Erythropoiesis-stimulating agent dosing did not differ between groups. The overall number of adverse events was similar; however, more infections were observed in the iron sucrose arm.

CONCLUSIONS

An equal cumulative dose of ferric carboxymaltose administered less frequently did not meet noninferiority for maintaining hemoglobin levels compared with iron sucrose administered more frequently.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Comparison Study of Two Iron Compounds for Treatment of Anemia in Hemodialysis Patients (COPEFER), NCT02198495.

Metabolic requirements of NK cells during the acute response against retroviral infection

Natural killer (NK) cells are important early responders against viral infections. Changes in metabolism are crucial to fuel NK cell responses, and altered metabolism is linked to NK cell dysfunction in obesity and cancer. However, very little is known about the metabolic requirements of NK cells during acute retroviral infection and their importance for antiviral immunity. Here, using the Friend retrovirus mouse model, we show that following infection NK cells increase nutrient uptake, including amino acids and iron, and reprogram their metabolic machinery by increasing glycolysis and mitochondrial metabolism. Specific deletion of the amino acid transporter Slc7a5 has only discrete effects on NK cells, but iron deficiency profoundly impaires NK cell antiviral functions, leading to increased viral loads. Our study thus shows the requirement of nutrients and metabolism for the antiviral activity of NK cells, and has important implications for viral infections associated with altered iron levels such as HIV and SARS-CoV-2.

Metabolic alterations control the fate and function of immune cells in response to infections, but the function of NK cell metabolism in the context of acute viral infections is unclear. Here the authors show that acute NK cell responses to Friend retrovirus involve increased glycolysis and mitochondrial metabolism and require amino acid transport as well as iron sufficiency.

Towards manufactured red blood cells for the treatment of inherited anemia

Patients with inherited anemia and hemoglobinopathies (such as sickle cell disease and β-thalassemia) are treated with red blood cell (RBC) transfusions to alleviate their symptoms. Some of these patients may have rare blood group types or go on to develop alloimmune reactions, which can make it difficult to source compatible blood in the donor population. Laboratory-grown RBC represent a particularly attractive alternative which could satisfy an unmet clinical need. The challenge, however, is to produce - from a limited number of stem cells - the 2x1012 RBC required for a standard adult therapeutic dose. Encouraging progress has been made in RBC production from adult stem cells under good manufacturing practice. In 2011, the Douay group conducted a successful proof-of-principle mini-transfusion of autologous manufactured RBC in a single volunteer. In the UK, a trial is planned to assess whether manufactured RBC are equivalent to RBC produced naturally in donors, by testing an allogeneic mini-dose of laboratory-grown manufactured RBC in multiple volunteers. This review discusses recent progress in the erythroid culture field as well as opportunities for further scaling up of manufactured RBC production for transfusion practice.

Intravenous ferric carboxymaltose does not provide benefits in reperfused acute myocardial infarction in the rat with normal iron status

BACKGROUND

Iron deficiency has been implicated in the pathophysiology of heart failure and myocardial ischemia and reperfusion injury. Moreover, reperfused heart seems to lose iron, thus even subjects with normal iron status could benefit from iron therapy. Impaired mitochondrial respiration and energy starvation may be among possible consequences of myocardial iron deficiency. So far no attempts have been made to treat acute coronary syndromes with iron. Thus our aim was to verify the hypothesis that intravenous iron therapy given during reperfusion of an acute myocardial infarction will reduce left ventricular remodeling and hemodynamic abnormalities in a 2-month follow-up as well as early mitochondrial dysfunction and mortality, in the rat with normal iron status.

METHODS AND RESULTS

A single dose of ferric carboxymaltose was administered intravenously at 30 min of reperfusion following 30 min of ischemia in the rat model of myocardial infarction. Ventricular arrhythmias were monitored using a telemetric system, activity of mitochondrial enzymes was assessed using spectrophotometry, serum markers of oxidative stress and inflammation were determined and left ventricular function and remodeling were monitored using echocardiography and pressure-volume loops. Intravenous iron therapy did not affect post-myocardial infarction mortality, left ventricular size or function, ventricular arrhythmias, activity of mitochondrial respiratory chain, oxidative stress or markers of inflammation, but was not associated with any adverse effects.

CONCLUSIONS

Although ferric carboxymaltose given at reperfusion was safe, it was ineffective in this model of reperfused myocardial infarction in the rat with normal iron status.

Serum iron and risk of nonalcoholic fatty liver disease and advanced hepatic fibrosis in US adults

Epidemiological evidence on the relationship between serum iron and liver diseases is limited. This study aims to investigate whether serum iron is associated with nonalcoholic fatty liver disease (NAFLD) and advanced hepatic fibrosis (AHF). Cross-sectional data for adults aged ≥ 18 years who participated in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018 were analyzed. Odds ratio (ORs) and 95% confidence intervals (CIs) of NAFLD and AHF associated with serum iron were estimated using multivariable logistic regression models. A total of 18,031 males and 18,989 females were included in the analysis. After multivariable adjustment for potential confounders, serum iron was significantly and inversely associated with NAFLD in both genders (P-trend < 0.001) and AHF in females (P-trend = 0.018). Compared to the bottom quartile, those in higher quartiles of serum iron had no significant ORs for AHF in males, but the trend across the quartiles was significant (P-trend = 0.046). In conclusion, higher serum iron level was associated with lower risk of NAFLD in males and females, and with lower risk of AHF in females but not in males. No significant racial/ethnical differences in these associations were observed.

Evaluation of the Physicochemical Properties of the Iron Nanoparticle Drug Products: Brand and Generic Sodium Ferric Gluconate

Complex iron nanoparticle-based drugs are one of the oldest and most frequently administered classes of nanomedicines. In the US, there are seven FDA-approved iron nanoparticle reference drug products, of which one also has an approved generic drug product (i.e., sodium ferric gluconate (SFG)). These products are indicated for the treatment of iron deficiency anemia and are administered intravenously. On the molecular level, iron nanomedicines are colloids composed of an iron oxide core with a carbohydrate coating. This formulation makes nanomedicines more complex than conventional small molecule drugs. As such, these products are often referred to as nonbiological complex drugs (e.g., by the nonbiological complex drugs (NBCD) working group) or complex drug products (e.g., by the FDA). Herein, we report a comprehensive study of the physiochemical properties of the iron nanoparticle product SFG. SFG is the single drug for which both an innovator (Ferrlecit) and generic product are available in the US, allowing for comparative studies to be performed. Measurements focused on the iron core of SFG included optical spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), X-ray powder diffraction (XRPD), ⁵⁷Fe Mössbauer spectroscopy, and X-ray absorbance spectroscopy (XAS). The analysis revealed similar ferric-iron-oxide structures. Measurements focused on the carbohydrate shell comprised of the gluconate ligands included forced acid degradation, dynamic light scattering (DLS), analytical ultracentrifugation (AUC), and gel permeation chromatography (GPC). Such analysis revealed differences in composition for the innovator versus the generic SFG. These studies have the potential to contribute to future quality assessment of iron complex products and will inform on a pharmacokinetic study of two therapeutically equivalent iron gluconate products.

An overview on mechanism, cause, prevention and multi-nation policy level interventions of dietary iron deficiency

Iron deficiency anemia (IDA) is probably the most ignored situation in the world of malnutrition-largely due to its slow progression. Multiple reasons can be attributed as the cause of IDA, which is not limited to any specific region or population; therefore, making it a matter of global concern. Despite the human body's ability to absorb and conserve iron stores, the gradual loss due to various physiological conditions leads to net deficiency of iron. Countless commercial iron supplements are available, but at given physiological conditions, almost all of these "Bio-not-available" iron forms quite often become ineffective. World Health Organization and other government bodies have jointly developed health advisories and tried to developed nutrition supplements several times in the last two decades. IDA, when combined with other disease conditions, becomes a life-threatening situation. At the same time, an overdose of iron could also be very harmful to the body. Therefore, it is important to deal with this situation with caution. This article covers iron metabolism, available options for iron supplementation, regulatory aspects and strategies to prevent IDA.

Effectiveness of iron polymaltose complex in treatment and prevention of iron deficiency anemia in children: a systematic review and meta-analysis

Background

Iron deficiency anemia (IDA) is commonly treated with iron formulations. Despite the expanding acceptance of iron polymaltose complex (IPC) among clinicians, there is sparse and contradictory evidence regarding its efficacy in the management of IDA in children. This systematic review and meta-analysis aimed to assess the effectiveness of IPC in the treatment and prevention of IDA in children.

Methods

We searched the Cochrane Central Register of Controlled Trials, MEDLINE and Epistemonikos for all randomized control trials (RCTs) comparing oral IPC with standard oral iron supplementation for the treatment or prevention of IDA in children. We independently screened the titles and abstracts of identified trials before the full text of relevant trials was evaluated for eligibility. We then independently extracted data on the methods, interventions, outcomes, and risk of bias from the included trials. A random-effects model was used to estimate the risk ratios and mean differences with 95% confidence intervals.

Results

Eight trials comprising 493 randomized patients were included and analyzed using three comparison groups. The comparison group of which was used to evaluate IPC and ferrous sulphate (FS) for treatment of IDA showed that IPC is less effective in increasing Hb (MD −0.81, 95% CI −1.08 to −0.53; I² = 48%, P < 0.001; six studies, 368 participants; high certainty of evidence), ferritin (MD −21.24, 95% CI −39.26 to −3.23, random-effects; I² = 65%, P = 0.020; 3 studies, 183 participants; moderate certainty of evidence) and MCV levels (MD −3.20, 95% CI −5.35 to −1.05; P = 0.003; one study, 103 participants; low certainty of evidence). There was no difference in the occurrence of side effects between IPC and FS group (MD 0.78, 95% CI 0.47 to 1.31; I² = 4%, P = 0.35; three studies, 274 participants; high certainty of evidence).

Conclusions

There was moderate to high certainty evidence that FS is superior to IPC with a clinically meaningful difference in improving the Hb and ferritin levels in the treatment of IDA in children. There was no difference in the occurrence of gastrointestinal side effects with high certainty evidence between the IPC and FS groups. The body of evidence did not allow a clear conclusion regarding the effectiveness of IPC with iron gluconate and iron bisglycinate in the prevention and treatment of IDA. The certainty of evidence was low. Adequately powered and high-quality trials with large sample sizes that assess both hematological and clinical outcomes are required.

PROSPERO registration number: CRD42019145020

The versatile biochemistry of iron in macrophage effector functions

Macrophages are mononuclear phagocytes with remarkable polarization ability that allow them to have tissue-specific functions during development, homeostasis, inflammatory and infectious disease. One particular trophic factor in the tissue environment is iron, which is intimately linked to macrophage effector functions. Macrophages have a well-described role in the control of systemic iron levels, but their activation state is also depending on iron-containing proteins/enzymes. Haemoproteins, dioxygenases and iron-sulphur (Fe-S) enzymes are iron-binding proteins that have bactericidal, metabolic and epigenetic-related functions, essential to shape the context-dependent macrophage polarization. In this review, I describe mainly pro-inflammatory macrophage polarization focussing on the role of iron biochemistry in selected haemoproteins and Fe-S enzymes. I show how iron, as part of haem or Fe-S clusters, participates in the cellular control of pro-inflammatory redox reactions in parallel with its role as enzymatic cofactor. I highlight a possible coordinated regulation of haemoproteins and Fe-S enzymes during classical macrophage activation. Finally, I describe tryptophan and α-ketoglutarate metabolism as two essential effector pathways in macrophages that use diverse iron biochemistry at different enzymatic steps. Through these pathways, I show how iron participates in the regulation of essential metabolites that shape macrophage function.