Intravenous iron administration and hypophosphatemia in clinical practice

Hypophosphatemia attenuates improvements in vitality after intravenous iron treatment in patients with inflammatory bowel disease

PURPOSE

Iron deficiency anemia is common in people with inflammatory bowel disease (IBD), causing deterioration in quality of life, which can be reversed by treatment that increases iron stores and hemoglobin levels. The present post hoc analyses estimate health state utility values for patients with IBD after treatment with ferric derisomaltose or ferric carboxymaltose and evaluate the health domains driving the changes.

METHODS

SF-36v2 responses were recorded at baseline and day 14, 35, 49, and 70 from 97 patients enrolled in the randomized, double-blind, PHOSPHARE-IBD trial (ClinicalTrials.gov ID: NCT03466983), in which patients with IBD across five European countries were randomly allocated to either ferric derisomaltose or ferric carboxymaltose. Changes in SF-36v2 scale scores and SF-6Dv2 health utility values were analyzed by mixed models.

RESULTS

In both treatment arms, SF-6Dv2 utility values and all SF-36v2 scale scores, except Bodily Pain, improved significantly (p =  < 0.0001). The improvement in SF-6Dv2 utility values showed no significant treatment group difference. The improvement in utility values was completely explained by improvement in Vitality scores. Vitality scores showed significantly larger improvement with ferric derisomaltose versus ferric carboxymaltose (p = 0.026). Patients with the smallest decrease in phosphate had significantly larger improvements in Vitality scores at each time point (p =  < 0.05 for all comparisons) and overall (p = 0.0006).

CONCLUSIONS

Utility values improved significantly with intravenous iron treatment. Improvement in utility values was primarily driven by Vitality scores, which showed significantly greater improvement in the ferric derisomaltose arm. Smaller decreases in phosphate were associated with significantly higher Vitality scores, suggesting that quality of life improvement is attenuated by hypophosphatemia. The utility values can inform future cost-utility analysis.

Intravenous Iron Repletion for Patients With Heart Failure and Iron Deficiency: JACC State-of-the-Art Review

Iron deficiency and heart failure frequently co-occur, sparking clinical research into the role of iron repletion in this condition over the last 20 years. Although early nonrandomized studies and subsequent moderate-sized randomized controlled trials showed an improvement in symptoms and functional metrics with the use of intravenous iron, 3 recent larger trials powered to detect a difference in hard cardiovascular outcomes failed to meet their primary endpoints. Additionally, there are potential concerns related to side effects from intravenous iron, both in the short and long term. This review discusses the basics of iron biology and regulation, the diagnostic criteria for iron deficiency and the clinical evidence for intravenous iron in heart failure, safety concerns, and alternative therapies. We also make practical suggestions for the management of patients with iron deficiency and heart failure and outline key areas in need of future research.

A case of hypophosphatemia and elevated intact fibroblast growth factor 23 levels after short-term saccharated ferric oxide administration in a young woman and database analysis of adverse drug reactions in Japan

Intravenous iron replacement therapy is a common treatment for iron deficiency. Commonly used agents in this treatment include ferric carboxymaltose, ferric derisomaltose, and saccharated ferric oxide (SFO). These drugs are known to elevate fibroblast growth factor 23 levels, resulting in hypophosphatemia, but in past reports, hypophosphatemia attributable to SFO treatment has been associated mainly with prolonged administration over several weeks. The present study details our experience of a case of moderate hypophosphatemia (<2 mg/dL) in a 22-year-old woman who had no specific history of hypophosphatemia during the first 5 days of SFO treatment, and showed an increase in intact fibroblast growth factor 23 levels within the first week of treatment. Cases of hypophosphatemia have been reported as occurring as early as 1 week after the start of SFO administration in the Japanese Adverse Drug Event Report database. These cases, along with our case, underline the need for awareness of the possibility of hypophosphatemia from the early stage of SFO administration, regardless of the patient's age or dosage, as well as the need to monitor patients to prevent complications.

Exploring progress in iron supplement formulation approaches for treating iron deficiency anemia through bibliometric and thematic analysis

Anemia is a severe health issue that affects around one-third of the global population. Therefore, the present study aims to conduct a bibliometric analysis to investigate the research trends regarding advancements on iron formulations in treating iron deficiency anemia via oral or parenteral route. This study adopts thematic and bibliometric methods on existing research on novel iron formulations. It also provides perspective into the existing understanding on treatment strategies for iron deficiency anemia. This study is conducted on 543 papers on various ferrous and ferric formulations used in the treatment of iron deficiency anemia. The study period is from 1977 to 2022, and the papers are identified from the Scopus database. The bibliometric analysis was carried out using the R tool's Bibliometrix package. The study discusses performance analysis, including annual publications, geographic analysis, relevant affiliations, journal analysis, and citation analysis. In addition, the conceptual structure, including the co-occurrence network, thematic map, thematic evolution, intellectual structure highlighting co-citation analysis, and social structure depicting the collaboration network and collaboration world map, are presented. The results showed increased research on formulation strategies for the treatment of iron deficiency anemia from 2010 onwards. The top 5 contributing countries are the USA, Italy, India, Germany, and the UK, and peer-reviewed journals from the area of nutrition. The most trending areas of study are iron deficiency anemia in pregnancy, chronic kidney diseases, inflammatory bowel diseases, and various intravenous formulations used in its treatment. The authors from Europe collaborate the most with authors from other countries. The study concludes that a safer and more effective iron formulation is needed to reduce the prevalence of anemia. The findings of the study are helpful in advancing research on innovative formulations for treating iron deficiency anemia. The insights from the study are helpful to policymakers in designing specific health policies and investing more in research and development of novel formulations for the treatment of iron deficiency anemia.

A randomized, controlled, open label non-inferiority trial of intravenous ferric carboxymaltose versus iron sucrose in patients with iron deficiency anemia in China

Iron deficiency (ID) and ID anemia (IDA) pose significant public health concerns in China. Although iron sucrose (IS) treatment is well-established in the country, ferric carboxymaltose (FCM) offers the advantage of higher doses and fewer infusions. This open label, randomized, controlled, non-inferiority trial was conducted at multiple sites in China to compare the outcomes of FCM (maximum of 2 doses, 500 or 1000 mg iron) and IS (up to 11 infusions, 200 mg iron) treatments in subjects with IDA. The primary endpoint was the achievement of hemoglobin (Hb) response (an increase of ⩾2 g/dL from baseline) within 8 weeks, whereas secondary endpoints included changes in Hb, transferrin saturation, and serum ferritin levels. Among the 371 randomized subjects, a similar percentage of subjects treated with FCM and IS achieved Hb-response (FCM 99.4%, IS 98.3%), thereby confirming the non-inferiority of FCM compared with IS (difference 1.12 (-2.15, 4.71; 95% confidence interval (CI))). Furthermore, a significantly higher proportion of FCM-treated subjects achieved early Hb-response at Week 2 (FCM 85.2%, IS 73.2%; difference 12.1 (3.31, 20.65; 95% CI)). Additionally, the increase in TSAT and serum ferritin levels from baseline was significantly greater at all time points for FCM-treated subjects. The safety profiles of FCM and IS were comparable, with the exception of transient hypophosphatemia and pyrexia, which are consistent with FCM's known safety profile. In conclusion, FCM proves to be an efficacious treatment for IDA, providing faster Hb-response and correction of ID with fewer administrations than IS.

Effect of intravenous iron on endogenous erythropoietin and FGF-23 secretion in patients with chronic kidney disease

INTRODUCTION

It has been observed that intravenous iron administration may suppress endogenous production of erythropoietin (EPO). We postulate that this effect may be mediated by increased FGF-23 secretion.

AIM OF THE STUDY

To evaluate the short-term effect of intravenous iron sucrose administration on endogenous EPO secretion in patients with chronic kidney disease (CKD).

MATERIALS AND METHODS

The cohort comprised 35 nondialysis patients with CKD stages 3-5. All received 100 mg of intravenous iron (III)-hydroxide sucrose complex daily for five consecutive days. Plasma EPO, iFGF-23, cFGF-23, PTH, bone alkaline phosphatase (BAP), phosphorus (PO4), calcium (Ca), and high-sensitive C-reactive protein (CRP) were measured before, and two hours after, the first and third iron infusions, and after completing iron therapy.

RESULTS

EPO concentration at the end of iron treatment was significantly lower than two hours after the first iron infusion (p = 0.0003) and before the third dose (p = 0.0006) (12.6 [10.2, 41.4] mIU/mL. vs. 30.9 [15.9, 54.2] mIU/mL and 33.4 [15.4, 56.7] mIU/mL, respectively). Conversely, plasma iFGF-23 was significantly higher before the third dose (61.1 [18.6, 420.1 4] pg/mL; p = 0.025) and after the course of treatment (92.1 [28.4, 878.1] pg/mL; p = 0.004) compared to pretreatment value (48.4 [16.2, 420] pg/mL). cFGF-23 concentration was significantly lower than baseline after the first iron dose (491.8 [257.7, 1086.3] vs. 339.2 [75.4, 951.2] RU/mL; p = 0.005) and after treatment (398.7 [90.4, 1022.3] RU/mL; p = 0.025). No significant linear correlation was found between changes in plasma EPO and FGF-23.

CONCLUSIONS

Although intravenous iron therapy causes parallel increase of FGF-23 and supression of endogenous EPO, these two effects seem to be independent.

[Hypophosphatemia after injectable iron treatments in adults: Comparison between ferric carboxymaltose and iron sucrose]

Hypophosphatemia is a recognized side effect of treatment of iron deficiency anemias with injectable iron. We analyzed 35 clinical trials that used ferric carboxymaltose (FCM) or iron sucrose (IS). Hypophosphatemia prevalence ranged from 0 to 91.7%. FCM-induced a significant (P<0.001) greater hypophosphatemia prevalence and phosphatemia decrease than IS (52.0% [95% CI: 42.2-61.8%] vs. 7.7% [95% CI: -2.8 to 18.2%] and -1.12mmol/L [95% CI: -1.36 to -0.89mmol/L] vs. -0.13mmol/L [95% CI: -0.59 to 0.32mmol/L]). FCM-induced hypophosphatemia was dose-dependent. The nadir of hypophosphatemia was reached in almost all studies after 7 and 14days. Hypophosphatemia persisted at the end of the study in 53.8% of the reported studies that used FCM and lasted up to 6months. FCM-induced an increase in intact circulating fibroblast growth factor 23 and in renal phosphorus excretion while serum 1-25 dihydroxyvitamin D was decreased. Risk factors for hypophosphatemia after FCM therapy were low basal circulating phosphate or ferritin, low body weight, high glomerular filtration rate, serum parathyroid hormone or hemoglobin and age, whereas renal insufficiency was associated with a lower risk. In conclusion, hypophosphatemia is common after treatment with injectable iron, FCM being associated with a higher risk than IS and with disorders of phosphocalcium metabolism. Monitoring of blood phosphate and 1-25 dihydroxyvitamin D could be considered during FCM therapy.

Efficacy and safety of intravenous iron sucrose in children younger than 2 years with intestinal failure

Iron-deficiency anemia (IDA) is highly prevalent in children with intestinal failure (IF) and oral iron supplementation is often ineffective in this patient population. Even though various intravenous (IV) iron formulations are available, there is a dearth of data on the use of newer parenteral iron products such as IV iron sucrose, especially in infants and young children (<2 years of age) with IF. To determine safety and efficacy, we performed a retrospective chart review on infants and children younger than 2 years with IF who received IV iron sucrose for IDA between October 2019 and August 2021. The review revealed that 10 events of IV iron sucrose replacement were administered to five children aged 4-22 months with IF and IDA. We observed a mean increase in hemoglobin of 1.9 ± 0.6 g/dl, and peak hemoglobin levels were seen at 4.3 ± 0.8 weeks after the IV iron sucrose dose. The infusions were well tolerated, and no short-term adverse reactions or laboratory abnormalities were observed. Based on these observations, the use of IV iron sucrose appears to be safe and effective in infants and young children with IF and could be considered in the management of IDA in this patient population.

High-Dose Intravenous Iron with Either Ferric Carboxymaltose or Ferric Derisomaltose: A Benefit-Risk Assessment

The intravenous iron formulations ferric carboxymaltose (FCM) and ferric derisomaltose (FDI) offer the possibility of administering a large amount of iron in one infusion. This results in faster correction of anemia and the formulations being better tolerated than oral iron formulations. This triad of logistic advantages, improved patient convenience, and fast correction of anemia explains the fact that intravenous iron formulations nowadays are frequently prescribed worldwide in the treatment of iron deficiency anemia. However, these formulations may result in hypophosphatemia by inducing a strong increase in active fibroblast growth factor-23 (FGF-23), a hormone that stimulates renal phosphate excretion. This effect is much more pronounced with FCM than with FDI, and therefore the risk of developing hypophosphatemia is remarkably higher with FCM than with FDI. Repeated use of FCM may result in severe osteomalacia, which is characterized by bone pain, Looser zones (pseudofractures), and low-trauma fractures. Intravenous iron preparations are also associated with other adverse effects, of which hypersensitivity reactions are the most important and are usually the result of a non-allergic complement activation on nanoparticles of free labile iron-Complement Activation-Related Pseudo-Allergy (CARPA). The risk on these hypersensitivity reactions can be reduced by choosing a slow infusion rate. Severe hypersensitivity reactions were reported in < 1% of prospective trials and the incidence seems comparable between the two formulations. A practical guideline has been developed based on baseline serum phosphate concentrations and predisposing risk factors, derived from published cases and risk factor analyses from trials, in order to establish the safe use of these formulations.

Severe Hypophosphatemia Following Ferric Carboxymaltose in a Patient With Inflammatory Bowel Disease

Inflammatory bowel disease is a chronic inflammatory condition that affects the large and small bowel, which includes Crohn’s disease (CD) and ulcerative colitis (UC). Iron deficiency anemia (IDA) is one of the most common complications in people with inflammatory bowel disease. The treatment of choice is intravenous iron infusion. There is a lack of awareness of side effects of intravenous iron (Ferinject) such as hypophosphatemia, which can prolong hospital admission. We present the case of a patient with iron deficiency anemia and vitamin D deficiency who developed severe hypophosphatemia after intravenous injection of ferric carboxymaltose (Ferinject). In this case presentation, our aim is to increase the awareness of prescribers about the risk of developing low phosphate levels after Ferinject and the need to monitor serum phosphate levels.

Intravenous Iron-Induced Hypophosphatemia: An Emerging Syndrome

Some, but not all, intravenous iron formulations have been recognized to induce renal phosphate wasting syndrome. Most commonly this has been reported following treatment of iron deficiency anemia (IDA) with ferric carboxymaltose (FCM). A search of PubMed identified relevant randomized controlled trials (RCTs), and case studies evaluating hypophosphatemia (HPP) resulting from intravenous iron treatment. While more recent larger comparative RCTs have confirmed that the majority of patients receiving FCM, especially those with normal renal function, may experience severe HPP, complete documentation is hampered by inconsistent reporting of serum phosphate in such trials. Similarly, while case series and RCTs have documented the persistence of HPP for several weeks or even months, the lack of studies lasting beyond 5–6 weeks has constrained full understanding of the duration of effect. Clinical trials have established that the mechanism involves the bone/metabolic axis with the elevation of intact fibroblast growth factor 23 playing the central role. Reports continue to accumulate of the clinical consequences of severe HPP which are, most commonly, bone abnormalities following repetitive dosing. Case reports and studies, however, have also shown that symptomatic hypophosphatemia can occur after a single FCM dose. The frequency of such events remains unknown, in part due to lack of awareness of hypophosphatemia coupled with the fact that the most common acute symptoms of HPP (fatigue and weakness) are the same for IDA and for many of the chronic diseases that cause IDA. Changes to US and European prescribing information for FCM should raise awareness of the potential for HPP and need to monitor patients at risk for it.

Newer formulations of intravenous iron: a review of their chemistry and key safety aspects - hypersensitivity, hypophosphatemia, and cardiovascular safety

Introduction: The newest intravenous (IV) iron products show an improved safety profile over predecessors, allowing for the rapid administration of relatively high doses. Ferric derisomaltose (FDI; also known as iron isomaltoside), ferric carboxymaltose (FCM), and ferumoxytol (FER), are successful treatments for iron deficiency (Europe; FDI and FCM) and iron deficiency anemia (US; FDI, FCM, and FER).Areas covered: This review focusses on the chemistry and structure of FDI, FCM, and FER, and on three key aspects of IV iron safety: (1) hypersensitivity; (2) hypophosphatemia and sequelae; (3) cardiovascular safety.Expert opinion: Although the safety of modern IV iron has improved, immediate infusion reactions and the development of hypophosphatemia must be appreciated and recognized by those who prescribe and administer IV iron. Immediate infusion reactions can occur with any IV iron and are usually mild; severe reactions - particularly anaphylaxis - are extremely rare. The recognition and appropriate management of infusion reactions is an important consideration to the successful administration of IV iron. Severe, persistent, hypophosphatemia is a specific side effect of FCM. No cardiovascular safety signal has been identified for IV iron. Ongoing trials in heart failure will provide additional long-term efficacy and safety data.

Parenteral iron therapy and phosphorus homeostasis: A review

Phosphorus has an essential role in cellular and extracellular metabolism; maintenance of normal phosphorus homeostasis is critical. Phosphorus homeostasis can be affected by diet and certain medications; some intravenous iron formulations can induce renal phosphate excretion and hypophosphatemia, likely through increasing serum concentrations of intact fibroblast growth factor 23. Case studies provide insights into two types of hypophosphatemia: acute symptomatic and chronic hypophosphatemia, while considering the role of pre‐existing conditions and comorbidities, medications, and intravenous iron. This review examines phosphorus homeostasis and hypophosphatemia, with emphasis on effects of iron deficiency and iron replacement using intravenous iron formulations.

[Hypophosphatemia following the administration of intravenous iron formulations: A case report and literature review]

Iron deficiency and iron-deficiency anemia are common medical conditions. Management of the etiology and iron supplementation are both necessary to treat this condition. Use of intravenous iron preparations is increasing due to its advantages over oral iron. Indeed, the total dose required can be provided in a single infusion, and it is more effective and increases hemoglobin levels more quickly than oral iron. Hypophosphatemia, sometimes severe, following intravenous iron administration, has been described in literature these past years, in particular with ferric carboxymaltose. We report here a case of severe hypophosphatemia with ferric carboxymaltose and carry out a literature review to determine the incidence of hypophosphatemia and to precise its clinical presentation, its pathophysiological mechanisms and its treatment. We found that hypophosphatemia is frequent with ferric carboxymaltose. Most of the time, there are no clinical manifestations, but cases of symptomatic osteomalacia have been described. Duration of hypophosphatemia is variable, from a few weeks to several months in case of prolonged administration. Hypophosphatemia owing to renal phosphate wasting is caused by an increase in intact fibroblast growth factor 23 (FGF-23) levels. However, the mechanism of ferric carboxymaltose- induced increase in intact FGF-23 is still unknown.

Hypophosphataemia, fibroblast growth factor 23 and third-generation intravenous iron compounds: a narrative review

Third-generation intravenous (i.v.) iron preparations are safe and efficacious and are increasingly used in the treatment of iron-deficiency anaemia. Hypophosphataemia is emerging as an established side-effect following the administration of certain compounds. Symptoms of hypophosphataemia can be masked by their similarity to those of iron-deficiency anaemia and both acute and chronic hypophosphataemia can be detrimental. Hypophosphataemia appears to be linked to imbalances in the metabolism of the phosphatonin fibroblast growth factor 23. In this narrative review, we discuss the possible pathophysiology behind this phenomenon, the studies comparing third-generation i.v. iron compounds, and the potential implications of the changes in fibroblast growth factor 23 and hypophosphataemia. We also present an algorithm of how to approach such patients requiring i.v. iron in anticipation of hypophosphataemia and how the impact related to it can be minimized.

Hypophosphataemia after treatment of iron deficiency with intravenous ferric carboxymaltose or iron isomaltoside-a systematic review and meta-analysis

Aims

Hypophosphataemia is an increasingly recognized side‐effect of ferric carboxymaltose (FCM) and possibly iron isomaltoside/ferric derisomaltose (IIM), which are used to treat iron deficiency. The aim of this study was to determine frequency, severity, duration and risk factors of incident hypophosphataemia after treatment with FCM and IIM.

Methods

A systematic literature search for articles indexed in EMBASE, PubMed and Web of Science in years 2005–2020 was carried out using the search terms ‘ferric carboxymaltose’ OR ‘iron isomaltoside’. Prospective clinical trials reporting outcomes on hypophosphataemia rate, mean nadir serum phosphate and/or change in mean serum phosphate from baseline were selected. Hypophosphataemia rate and severity were compared for studies on IIM vs. FCM after stratification for chronic kidney disease. Meta‐regression analysis was used to investigate risk factors for hypophosphataemia.

Results

Across the 42 clinical trials included in the meta‐analysis, FCM induced a significantly higher incidence of hypophosphataemia than IIM (47%, 95% CI 36–58% vs. 4%, 95% CI 2–5%), and significantly greater mean decreases in serum phosphate (0.40 vs. 0.06 mmol/L). Hypophosphataemia persisted at the end of the study periods (maximum 3 months) in up to 45% of patients treated with FCM. Meta‐regression analysis identified low baseline serum ferritin and transferrin saturation, and normal kidney function as significant predictors of hypophosphataemia.

Conclusion

FCM is associated with a high risk of hypophosphataemia, which does not resolve for at least 3 months in a large proportion of affected patients. More severe iron deficiency and normal kidney function are risk factors for hypophosphataemia.

A Pooled Analysis of Serum Phosphate Measurements and Potential Hypophosphataemia Events in 45 Interventional Trials with Ferric Carboxymaltose

Ferric carboxymaltose (FCM) has been shown to achieve rapid replenishment of iron stores and correction of anaemia in various populations with iron deficiency. A decrease in serum phosphate (PO₄³⁻) levels, which in most cases is asymptomatic, has been reported with IV iron preparations. Hypophosphataemia (HP) is a known adverse drug reaction with FCM. This post hoc pooled analysis investigates the frequency, duration, risk factors, and clinical signs of HP as reported in interventional clinical trials with FCM. Pooled data from subjects enrolled across 45 clinical trials in different therapy areas were included. A three-step adjudication process was utilised to identify adverse events of HP. Stratified analyses by therapy group and stepwise logistic regression analysis were used to identify predictors of HP. This pooled analysis confirms that FCM is associated with increased rates of serum PO₄³⁻ lowering, but mean serum PO₄³⁻ values were seen to recover at Week 4 and further recover at Week 8. Among all subjects receiving FCM therapy (n = 6879), 41.4% (n = 2847) reached a PO₄³⁻ nadir value <2.5 mg/dL at any point on study and 0.7% (n = 49) reached a nadir <1 mg/dL. Although gastroenterology and women’s health subjects were identified to be at higher risk, occurrence of severe HP (<1 mg/dL [0.3 mmol/L]) following FCM administration was not observed to be common among subjects in these studies. Furthermore, there was no correlation between laboratory serum PO₄³⁻ values and the occurrence of reported adverse events related to low PO₄³⁻ levels.

Severe Symptomatic Hypophosphataemia as a Complication of Parenteral Iron Replacement

Parental iron replacement is given to patients with severe iron deficiency or intolerance to oral iron. Hypophosphataemia has been reported to occur as a complication of parental iron replacement, and is postulated to be related to the carbohydrate moieties used in the parenteral preparations. Hypophosphataemia is under-diagnosed as symptoms such as fatigue, muscle weakness and poor effort tolerance mimic anaemia. Severe hypophosphataemia (<0.32 mmol/l) can result in significant complications such as confusion, rhabdomyolysis and arrhythmias. We report a patient with recurrent admissions for non-specific symptoms attributed to iron deficiency anaemia who received multiple doses of parenteral ferric carboxymaltose (FCM). He was found to have severe hypophosphataemia, with further evaluation showing increased renal phosphate wasting and elevated serum levels of fibroblast-growth-factor 23 (FGF23). FCM was stopped and he was given high-dose oral iron supplementation, with no further episodes of hypophosphataemia.

LEARNING POINTS

The carbohydrate moieties used in parenteral iron preparations are different, and may have a dose-dependent relationship with the development of hypophosphataemia.The mechanism by which hypophosphataemia occurs after parenteral iron replacement is related to increased serum levels of FGF23, which increases renal phosphate wasting.The serum phosphate levels of patients receiving parenteral iron replacement (especially ferric carboxymaltose or iron polymaltose) should be routinely monitored for hypophosphataemia, which is an under-diagnosed complication.

Hypophosphataemia after ferric carboxymaltose is unrelated to symptoms, intestinal inflammation or vitamin D status

Background

Intravenous iron replacement is recommended for iron-deficient patients with inflammatory bowel disease (IBD), but may be associated with hypophosphataemia, predisposing to osteomalacia and fractures. This study aimed to evaluate the incidence and risk factors for hypophosphataemia following intravenous ferric carboxymaltose (FCM) in patients with IBD.

Methods

This prospective observational study of patients with and without IBD evaluated serum phosphate for 28 days following intravenous FCM, and assessed associations with symptoms, markers of inflammation and vitamin D status.

Results

Twenty-four patients with IBD (11 with Crohn’s disease [CD], 13 with ulcerative colitis [UC], mean age 45 years [range 19–90], 7 female), and 20 patients without IBD (mean age 56 [22–88] y, 11 female), were included. Overall, serum phosphate declined by a mean of 36% at Day 7, with a mean fall of 42% (SD 19%) at some time point over 28 days (p <  0.001). Twenty-four of 44 (55%) patients developed moderate to severe hypophosphataemia (serum phosphate < 0.6 mmol/L). No differences between patients with and without IBD were seen, but patients with CD had greater decline in phosphate than those with UC. There was no association between hypophosphataemia and symptomatic adverse events, faecal calprotectin, C-reactive protein, albumin, platelet count, 25(OH) vitamin D, or 1,25(di-OH) vitamin D. Serum phosphate < 1.05 mmol/L on Day 2 predicted susceptibility to moderate-severe hypophosphataemia (OR 7.0).

Conclusions

Hypophosphataemia following FCM is common, unrelated to symptomatic adverse events, baseline intestinal or systemic inflammation, or vitamin D status.

Hypophosphatemia Associated with Intravenous Iron Therapies for Iron Deficiency Anemia: A Systematic Literature Review

Background

Iron deficiency anemia (IDA) is a prevalent yet underdiagnosed condition with a significant impact on quality of life. Oral iron supplementation is often poorly tolerated or yields inadequate response, requiring the use of intravenous iron (IVI) in some patients. Administration of certain IVI preparations has been associated with decreases in serum phosphate levels and clinically significant hypophosphatemia, which has been reported to lead to adverse events including serious fatigue and osteomalacia.

Objective

The purpose of this study was to systematically assess the prevalence, clinical consequences, and reporting of treatment-emergent hypophosphatemia within literature investigating IVI therapies marketed in the United States (US).

Methods

A systematic literature review (SLR) was conducted using the PubMed database to identify publications reporting serum phosphate levels or rates of hypophosphatemia within adult IDA patient populations receiving current US-marketed IVIs.

Results

The SLR yielded 511 unique publications, with 40 records meeting the final inclusion criteria. Most studies did not report phosphate monitoring methodology or an explicit definition of hypophosphatemia. Hypophosphatemia rates ranged from 0.0% to 92.1% for ferric carboxymaltose (FCM), 0.0% to 40.0% for iron sucrose, 0.4% for ferumoxytol, and 0.0% for low-molecular-weight (LMW) iron dextran. Randomized controlled studies described hypophosphatemia as “asymptomatic” or did not report on other associated sequelae. Eleven case reports detailed treatment-emergent hypophosphatemia in patients treated with FCM. Patients with acute hypophosphatemia primarily developed severe fatigue; those with repeated FCM dosing developed chronic hypophosphatemia associated with osteomalacia and bone deformities.

Conclusion

Studies analyzed in this SLR reported a range of hypophosphatemia rates, with the highest consistently seen in patients treated with FCM. Across the clinical literature, there appeared to be minimal standardization of phosphate monitoring and definitions of hypophosphatemia. Although multiple cases have documented serious clinical consequences of hypophosphatemia associated with certain IVIs, current trials neither consistently nor adequately assess the frequency and severity of treatment-emergent hypophosphatemia and may underestimate its prevalence.

High Risk of Hypophosphatemia in Patients with Previous Bariatric Surgery Receiving Ferric Carboxymaltose: A Prospective Cohort Study

BACKGROUND

Iron deficiency is a common finding in patients with previous bariatric surgery, and parenteral supplementation is frequently required. Ferric carboxymaltose (FCM) is among the preferred compounds used but may be associated with new-onset hypophosphatemia. This study was undertaken to study the prevalence of hypophosphatemia following FCM in patients with previous bariatric surgery, a population that may be at particular risk due to highly prevalent secondary hyperparathyroidism.

METHODS

Patients with previous bariatric surgery and iron depletion scheduled for FCM infusion were prospectively studied before and one week after FCM application. The primary endpoint was new-onset hypophosphatemia. Patients were followed until plasma phosphate had normalized without replacement.

RESULTS

Fifty-two patients (40 females) following Roux-en-Y gastric bypass (n = 50) or sleeve gastrectomy (n = 2), with a median age of 46 years (range 22-68) and a BMI of 32.2 kg/m² (27.5-37.3), were analyzed. Fifteen patients (29%) developed new-onset hypophosphatemia, with 11 (21%) requiring oral phosphate supplementation for a median duration of 14 days (14-25). The plasma phosphate decreased by 0.3 mmol/l (-0.5--0.2; p < 0.001) secondary to a 56% increase in the fractional urinary phosphate excretion (p < 0.001). This was associated with a significant increase in serum intact FGF23 (+30%; p < 0.001) and a decrease in serum 1,25(OH)2 vitamin D3 concentrations (-37.6%; p < 0.001).

CONCLUSION

Patients with previous bariatric surgery receiving FCM are at considerable risk of developing significant hypophosphatemia secondary to increased renal phosphate wasting through a mechanism involving FGF23. Monitoring plasma phosphate should be considered following FCM in patients with previous bariatric surgery.

CLINICAL TRIAL REGISTRATION

ISRCTN registry, ISRCTN12291677, https://www.isrctn.com.

Iron and Heart Failure: Diagnosis, Therapies, and Future Directions

To date, 3 clinical trials have shown symptomatic benefit from the use of intravenous (IV) iron in patients with heart failure (HF) with low serum iron. This has led to recommendations in support of the use of IV iron in this population. However, the systemic and cellular mechanisms of iron homeostasis in cardiomyocyte health and disease are distinct, complex, and poorly understood. Iron metabolism in HF appears dysregulated, but it is still unclear whether the changes are maladaptive and pathologic or compensatory and protective for the cardiomyocytes. The serum markers of iron deficiency in HF do not accurately reflect cellular and mitochondrial iron levels, and the current definition based on the ferritin and transferrin saturation values is broad and inclusive of patients who do not need IV iron. This is particularly relevant in view of the potential risks that are associated with the use of IV iron. Reliable markers of cellular iron status may differentiate subgroups of HF patients who would benefit from cellular and mitochondrial iron chelation rather than IV iron.

Recurrent severe hypophosphatemia following intravenous iron administration

Hypophosphatemia postintravenous iron is frequent but under-recognized. If prolonged or recurrent, it can cause osteomalacia. The likely mechanisms are direct toxicity to proximal tubular cells causing phosphate wasting, elevated Fibroblast growth factor-23 (FGF-23), and reduced 1,25-dihydroxyvitamin D (1,25(OH)2D). Hypophosphatemia may be severe and persist for months, necessitating phosphate replacement until normalization of serum levels occurs.

Intravenous ferric carboxymaltose is effective and safe in patients with inflammatory rheumatic diseases

BACKGROUND

The aim of this study was to evaluate the efficacy and safety of ferric carboxymaltose in rheumatic patients with iron deficiency anaemia.

MATERIALS AND METHODS

The study retrospectively evaluated a cohort of 34 patients with iron deficiency anaemia affected by inflammatory rheumatic diseases that are refractory or intolerant to oral iron therapy. They were treated with ferric carboxymaltose for a total of 56 cycles of treatment. The primary end point was to evaluate the increase of haemoglobin after ferric carboxymaltose treatment. The secondary end point was safety, including the occurrence of disease flare.

RESULTS

Median age of the cohort was 60 years (range 31-91 years), with a male/female ratio of 4/30. Nine (26.5%) were affected by rheumatoid arthritis, 10 (29.4%) by spondyloarthritis, and 15 (44.1%) by other autoimmune connective tissue diseases. Median time from diagnosis was 7 years (IQR 2-12). At time of treatment (T₀), median haemoglobin was 9.3 g/dL (IQR 8.2-10.3), transferrin saturation 6.2% (IQR 3.8-9.8), and ferritin 8.5 ng/mL (IQR 6.0-12.8). Median ferric carboxymaltose dose was 1,000 mg. At 6 weeks from T₀, median haemoglobin was 12.3 g/dL (IQR 11.6-13.3), with a mean increase of 3.0 g/dL (p<0.01). Twelve (35.3%) patients needed re-treatment with ferric carboxymaltose for recurrence of iron deficiency anaemia. Four (4.3%) patients developed mild grade side effects. One suspected flare reaction has been observed.

DISCUSSION

In patients affected by inflammatory rheumatic diseases, ferric carboxymaltose is safe and effective in correcting iron deficiency anaemia.

Metabolic bone diseases in intestinal failure

Metabolic bone diseases are a group of conditions that are common complications in patients with intestinal failure. These may occur as a result of the underlying condition, leading to intestinal failure, particularly inflammatory conditions such as Crohn's disease and their associated treatments including corticosteroids. Malabsorption, as a result of a loss of enterocyte mass or gut function, of many nutrients, including vitamin D, may further compound metabolic bone problems, and there has been historical contamination of parenteral nutrition with aluminium that has prevented normal bone metabolism contributing to osteoporosis. This review looks at the diagnosis and current management of bone health in patients with intestinal failure.

Symptomatic hypophosphataemia after intravenous iron therapy: an underrated adverse reaction

Iron (ferric carboxymaltose) infusion therapy is used to treat severe iron deficiency which is not responding to the first-line oral iron therapy. However, it can also cause severe renal wasting of phosphate resulting in severe hypophosphataemia in some patients. Despite the growing number of case reports, this side effect is not well known to healthcare professionals. The product labelling information sheet does mention that hypophosphataemia can be a side effect, but also says that this side effect is usually transient and asymptomatic. We report a challenging case of a patient who developed severe, symptomatic and prolonged hypophosphataemia after an intravenous iron infusion for severe iron deficiency.

Ferric Carboxymaltose: A Review in Iron Deficiency

Intravenous ferric carboxymaltose (Ferinject^®; Injectafer^®) is a colloidal solution of nanoparticles which consist of a polynuclear iron (III)-(oxyhydr)oxide core stabilized by carboxymaltose and may be given as a single high-dose, 15-min infusion. This article reviews the clinical use of ferric carboxymaltose in various patient populations with iron deficiency (ID) [± anaemia] and briefly summarizes its pharmacological properties. Based on extensive experience in the clinical trial and real-world settings, ferric carboxymaltose is an effective and generally well tolerated treatment for rapidly replenishing iron stores and correcting anaemia in patients with ID (± anaemia) of various aetiologies, including patients with chronic heart failure (CHF), chronic kidney disease, inflammatory bowel disease or perioperative anaemia, and women with ID during pregnancy, postpartum or associated with heavy uterine bleeding. As it may be given as a single high-dose infusion, ferric carboxymaltose has the potential to provide cost savings from a healthpayer perspective. Thus, ferric carboxymaltose remains an important option for the treatment of ID in adults and, where approved, children aged ≥ 14 years, when oral iron preparations are ineffective or cannot be used.

Symptomatic severe hypophosphatemia after intravenous ferric carboxymaltose

Intravenous iron is commonly prescribed for treatment of iron deficiency, with modern formulations demonstrating an acceptable safety profile in the majority of patients. We report the case of a patient who was hospitalised with muscle pain, deteriorating mobility and multiple fractures following repeated ferric carboxymaltose infusions. Investigations revealed severe hypophosphatemia with serum phosphate of 0.27 mmol/L, 25‐hydroxyvitamin D (25OHD) level of 32 nmol/L and insufficiency fractures of the sacrum and L5 transverse process. The patient's hypophosphatemia was corrected with several infusions of intravenous phosphate, as well as oral phosphate and calcitriol, with subsequent resolution of her muscle aches, back pain and immobility.

The risk of persistent hypophosphatemia and osteomalacia may be higher with iron carboxymaltose than other iron formulations and a transient increase in intact fibroblast growth factor‐23 with reduced renal tubular phosphate absorption has been postulated as the key mechanism. This risk appears increased by repeated iron infusions, underlying malnutrition, hypophosphatemia at baseline, vitamin D deficiency, hyperparathyroidism or anti‐resorptive medication use. The true risk and incidence of hypophosphatemia need to be clarified so that appropriate monitoring, prevention and treatment strategies can be developed.

Randomized trial of intravenous iron-induced hypophosphatemia

BACKGROUND

Hypophosphatemia can complicate intravenous iron therapy, but no head-to-head trials compared the effects of newer intravenous iron formulations on risks and mediators of hypophosphatemia.

METHODS

In a randomized, double-blinded, controlled trial of adults with iron deficiency anemia from February 2016 to January 2017, we compared rates of hypophosphatemia in response to a single FDA-approved course of ferric carboxymaltose (n = 1,000) or ferumoxytol (n = 997). To investigate pathophysiological mediators of intravenous iron-induced hypophosphatemia, we nested within the parent trial a physiological substudy (ferric carboxymaltose, n = 98; ferumoxytol, n = 87) in which we measured fibroblast growth factor 23 (FGF23), calcitriol, and parathyroid hormone (PTH) at baseline and 1, 2, and 5 weeks later.

RESULTS

The incidence of hypophosphatemia was significantly higher in the ferric carboxymaltose versus the ferumoxytol group (<2.0 mg/dl, 50.8% vs. 0.9%; <1.3 mg/dl, 10.0% vs. 0.0%; P < 0.001), and hypophosphatemia persisted through the end of the 5-week study period in 29.1% of ferric carboxymaltose-treated patients versus none of the ferumoxytol-treated patients (P < 0.001). Ferric carboxymaltose, but not ferumoxytol, increased circulating concentrations of biologically active FGF23 (mean within-patient percentage change from baseline to week 2 peak: +302.8 ± 326.2% vs. +10.1 ± 61.0%; P < 0.001), which was significantly associated with contemporaneous hypophosphatemia, renal phosphate wasting, and decreased serum calcitriol and calcium, and increased PTH concentrations.

CONCLUSIONS

Ferric carboxymaltose rapidly increases biologically active FGF23 in patients with iron deficiency anemia. Paralleling hereditary and other acquired syndromes of hypophosphatemic rickets/osteomalacia, ferric carboxymaltose-induced FGF23 elevation triggers a pathophysiological cascade of renal phosphate wasting, calcitriol deficiency, and secondary hyperparathyroidism that frequently culminates in hypophosphatemia.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02694978FUNDING. AMAG Pharmaceuticals, Inc.Role of the funding source: This study was supported by AMAG Pharmaceuticals, Inc. The academic investigators designed the clinical trial, performed the analyses, and authored the manuscript with input from the coauthors from AMAG Pharmaceuticals, Inc.

Switching iron sucrose to ferric carboxymaltose associates to better control of iron status in hemodialysis patients

BACKGROUND

Although the efficacy of iron sucrose (IS) and ferric carboxymaltose (FCM) in treating anemia in hemodialysis (HD) patients has been studied individually, a comparison of these two intravenous iron formulations has not yet been performed in HD patients.

METHODS

We performed a retrospective audit on records of 221 stable HD patients from different HD centers in the Netherlands, who were switched from IS to FCM on a 1:1 ratio. To assess the effect of the switch on iron status parameters, data from 3 time points before and 3 time points after the switch were analyzed using linear mixed effects models. Subanalyses were done in 2 subgroups of patients anemic or iron deficient at baseline.

RESULTS

Hemoglobin increased in all groups (anemic [1.4 g/dL, P < 0.001] iron deficient [0.6 g/dL, P < 0.001]), while the weekly iron dose was significantly lower when patients received FCM compared to IS (48 vs 55 mg/week, P = 0.04). Furthermore, serum ferritin and transferrin saturation increased in all groups (anemic [64 μg/L, 5.0%, P < 0.001] iron deficient [76 μg/L, 3.6%, P < 0.001]). Finally, the darbepoetin α dose decreased significantly in all groups (anemic [- 16 μg/wk., P = 0.01] iron deficient [- 11 μg/wk., P < 0.001]).

CONCLUSIONS

In this real-life study in HD patients, a switch from IS to FCM resulted in an improvement of iron status parameters despite a lower weekly dose of FCM. Furthermore, the ESA dose was reduced during FCM, while hemoglobin levels increased.

Mineral and Bone Disorders After Kidney Transplantation

The risk of mineral and bone disorders among patients with chronic kidney disease is substantially elevated, owing largely to alterations in calcium, phosphorus, vitamin D, parathyroid hormone, and fibroblast growth factor 23. The interwoven relationship among these minerals and hormones results in maladaptive responses that are differentially affected by the process of kidney transplantation. Interpretation of conventional labs, imaging, and other fracture risk assessment tools are not standardized in the post-transplant setting. Post-transplant bone disease is not uniformly improved and considerable variation exists in monitoring and treatment practices. A spectrum of abnormalities such as hypophosphatemia, hypercalcemia, hyperparathyroidism, osteomalacia, osteopenia, and osteoporosis are commonly encountered in the post-transplant period. Thus, reducing fracture risk and other bone-related complications requires recognition of these abnormalities along with the risk incurred by concomitant immunosuppression use. As kidney transplant recipients continue to age, the drivers of bone disease vary throughout the post-transplant period among persistent hyperparathyroidism, de novo hyperparathyroidism, and osteoporosis. The use of anti-resorptive therapies require understanding of different options and the clinical scenarios that warrant their use. With limited studies underscoring clinical events such as fractures, expert understanding of MBD physiology, and surrogate marker interpretation is needed to determine ideal and individualized therapy.

Current misconceptions in diagnosis and management of iron deficiency

The prevention and treatment of iron deficiency is a major public health goal. Challenges in the treatment of iron deficiency include finding and addressing the underlying cause and the selection of an iron replacement product which meets the needs of the patient. However, there are a number of non-evidence-based misconceptions regarding the diagnosis and management of iron deficiency, with or without anaemia, as well as inconsistency of terminology and lack of clear guidance on clinical pathways. In particular, the pathogenesis of iron deficiency is still frequently not addressed and iron not replaced, with indiscriminate red cell transfusion used as a default therapy. In our experience, this imprudent practice continues to be endorsed by non-evidence-based misconceptions. The intent of the authors is to provide a consensus that effectively challenges these misconceptions, and to highlight evidence-based alternatives for appropriate management (referred to as key points). We believe that this approach to the management of iron deficiency may be beneficial for both patients and healthcare systems. We stress that this paper solely presents the Authors' independent opinions. No pharmaceutical company funded or influenced the conception, development or writing of the manuscript.

Severe FGF23-based hypophosphataemic osteomalacia due to ferric carboxymaltose administration

Ferric carboxymaltose (FCM) is a novel iron formulation increasingly prescribed due to its effectiveness and fast infusion time. FCM administration can cause an asymptomatic hypophosphataemia secondary to fibroblast growth factor 23 (FGF23) dysregulation. In patients with chronic iron needs, however, a severe, long-lasting hypophosphataemia can lead to osteomalacia with associated bone pain. Lack of awareness of this complication results in delayed time to diagnosis and significant morbidity. We report a case of a patient with Crohn's disease and chronic iron-deficiency anaemia receiving multiple doses of FCM who developed severe hypophosphataemic osteomalacia with urinary phosphate loss and increased FGF23. FGF23 excess and osteomalacia resolved only months after FCM discontinuation and aggressive phosphate repletion. Potential mechanisms of FGF23 dysregulation are discussed, with the aim of raising awareness of this significant side effect for prescribers of chronic intravenous iron supplementation, and to help guide future studies to determine the safety of FCM in all patient populations.

Management of anemia in inflammatory bowel disease: a challenge in everyday clinical practice

Anemia is the most common extraintestinal manifestation and complication of inflammatory bowel disease (IBD). Its etiology is multifactorial and mostly is a combination of iron deficiency anemia (IDA) and chronic anemia (ACD). Because of its high incidence in patients with IBD and its influence on their quality of life, regular screening is recommended. In case of IDA type of medication and route of administration should be determined by many factors such as general condition of the patient, IBD activity or anemia severity. Intravenous iron supplementation is the preferred route but may be associated with phosphate drop or even severe hypophosphatemia (HP). The mechanism of HP related to the intravenous iron infusions is not clearly known yet, but it might be related to the change of FGF-23 levels. What more not all parenteral forms of iron are equal and some may have a higher risk of HP than others.

Management of inflammatory bowel disease-related anemia and iron deficiency with specific reference to the role of intravenous iron in current practice

INTRODUCTION

Anemia is a common extraintestinal manifestation in patients with inflammatory bowel disease, impacting disease prognosis, morbidity, hospitalization rates and time lost from work. While iron deficiency anemia and anemia of chronic inflammation predominate, combinations of hematimetric and biochemical markers facilitate the diagnosis and targeted therapy of other etiologies according to their underlying pathophysiological causes. Intravenous iron replacement is currently recommended in IBD patients with moderate to severe anemia or intolerance to oral iron. Areas covered: This review examines the impact, pathophysiology and diagnostics of iron deficiency and anemia, compares the characteristics and safety profiles of available oral and intravenous iron preparations, and highlights issues which require consideration in decision making for therapy administration and monitoring. Expert opinion: Modern intravenous iron formulations have been shown to be safe and effective in IBD patients, allowing rapid anemia correction and repletion of iron stores. While traditional oral iron preparations are associated with increased inflammation, negative effects on the microbiome, and poor tolerance and compliance, first clinical trial data indicate that newer oral compounds such as ferric maltol and sucrosomial iron offer improved tolerability and may thus offer a viable alternative for the future.

Severe hypophosphataemia after intravenous iron administration

Iron deficiency is common and can be effectively treated with parenteral iron infusion. We report a case of an iron-deficient and vitamin D-deficient woman who developed severe symptomatic hypophosphataemia following intravenous ferric carboxymaltose administration. We stress the need of increased awareness of this potential complication among physicians. Patients should be informed of this complication and instructed to report for follow-up if they experience new musculoskeletal symptoms or worsening of tiredness. As severe hypophosphataemia is usually symptomatic, we recommend screening symptomatic patients for this complication. Recognising and treating the possible exacerbating factors, especially vitamin D deficiency, might be a simple measure to mitigate this complication.

Drug-specific hypophosphatemia and hypersensitivity reactions following different intravenous iron infusions

AIMS

Intravenous (IV) iron infusions have been associated with hypophosphataemia (HP) and hypersensitivity reactions (HSRs). No studies have compared the side effects of ferric carboxymaltose (FCM) with those of isomaltoside 1000 (ISM). This study aimed to describe the occurrence of HP and HSRs following the administration of either FCM or ISM.

METHODS

Data on 231 outpatients treated with IV iron infusions, between November 2011 and April 2014, were collected. During that period, the department made a switch from FCM to ISM and then back to FCM. Of the 231 patients, 39 received both FCM and ISM during the period. The prevalences of HP and HSRs were compared between the two drugs.

RESULTS

We found more HP events when FCM was given (64 vs. 9; P < 0.01). In contrast, more patients had mild HSRs when ISM was given (2.5% vs. 10.7%; P < 0.01). A comparison of the two drugs in the subpopulation who received both drug types (n = 39) revealed a difference in phosphate decrease (P < 0.01), with the most marked decrease occurring with FCM. Nine patients who had HSRs were exposed to both drugs. No potential HSR crossover between the two drugs was found.

CONCLUSION

We found a higher risk of HP with FCM administration when compared to ISM administration. Conversely, we found a higher risk of mild HSRs with ISM administration when compared to FCM administration. The impacts of the two types of side effects should be considered when choosing an IV iron drug.

Long-term iron polymaltose infusions associated with hypophosphataemic osteomalacia: a report of two cases and review of the literature

Iron-induced hypophosphataemic osteomalacia remains under-recognized as a potential complication of parenteral iron therapy. We here report two cases of symptomatic hypophosphataemic osteomalacia with multiple insufficiency fractures in the context of chronic gastrointestinal blood loss, necessitating monthly iron polymaltose infusions over prolonged periods of time. Respective blood tests revealed severe hypophosphataemia [0.29 and 0.43; normal range (NR) 0.8-1.5 mmol/l] in the presence of normal serum calcium and 25-hydroxy vitamin D levels. Urinary fractional phosphate excretion was elevated (16% and 24%; NR < 5%) and the tubular maximum phosphate reabsorption was reduced, consistent with renal phosphate wasting. Serum fibroblast growth factor 23 (FGF23) obtained in one patient was significantly elevated at 285 pg/ml (NR < 54 pg/ml). Bone mineral density was significantly reduced and whole-body bone scans revealed metabolic bone disease and multiple insufficiency fractures consistent with osteomalacia. Cessation of iron infusions resulted in clinical and biochemical improvement within 2 months in one patient whereas the second patient required phosphate and calcitriol supplementation to improve symptomatically. Iron-induced hypophosphataemic osteomalacia is thought to be due to reduced degradation of FGF23, resulting in phosphaturia and reduced synthesis of 1,25-dihydroxy vitamin D. Monitoring of patients on long-term parenteral iron is recommended to avoid clinically serious adverse effects.

High-dose intravenously administered iron versus orally administered iron in blood donors with iron deficiency: study protocol for a randomised, controlled trial

Background

About 2–3 % of the population participates in blood donation programmes. Each whole blood donation or ten apheresis donations cause a loss of 200–250 mg of iron. As a result, one of the most common risks of regular blood donors is iron deficiency. Although this has been known for decades, in most countries, iron status is currently not assessed or treated in this population. Premenopausal women are particularly affected, as they have lower iron reserves and higher daily requirements. Besides anaemia, iron deficiency may lead to fatigue and impaired cognitive and physical performance. Current iron preparations for intravenous administration are well tolerated and allow for application of large doses up to 1 g in one visit. Our hypothesis is that in blood donors with iron deficiency, intravenously administered iron is more efficient and as safe as oral iron supplementation. Since anaemia is one of the most frequent reasons for permanent or intermittent donor deferral, maintaining an iron-replete donor pool may help to prevent shortages in blood supply and to avoid iron deficiency-related comorbidities.

Methods/design

In this randomised clinical trial we include male and female blood donors aged ≥18 and ≤65 years with a ferritin value of ≤30 ng/ml. Stratified by gender, participants are randomized with a web-based randomisation tool in a 1:1 ratio to either 1 g of intravenously administered ferric carboxymaltose or 10 g of iron fumarate supplements at one to two daily doses of 100 mg each. Eight to 12 weeks after the first visit, iron status, blood count and symptoms are assessed in both groups. The primary endpoint is the difference in transferrin saturation (%) following the intervention between both groups. Secondary endpoints include other parameters of iron metabolism and red blood cell count, the number of patients with drug-related adverse events, and subjective symptoms including those of the restless legs syndrome, quality of life, and fatigue.

Discussion

Iron supplementation administered intravenously in non-anaemic but iron-deficient blood donors could represent an effective strategy to protect blood donors from comorbidities related with iron deficiency and therefore improve blood donor wellbeing. Furthermore, iron supplementation will help to maintain an iron-replete blood donor pool.

Trial registration

EudraCT: 2013-000327-14, Clinical Trials Identifier: NCT01787526. Registered on 6 February 2013.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1648-y) contains supplementary material, which is available to authorized users.

Ferric carboxymaltose reduces the number of red blood cell units transfused and allows transfusion independence to be obtained in patients with iron deficiency anemia secondary to gastrointestinal chronic blood loss

BACKGROUND

The aim of this study was to evaluate the effectiveness of ferric carboxymaltose (FCM) in patients with iron deficiency anemia (IDA) secondary to gastrointestinal chronic blood loss (CBL), who received chronic transfusion support.

STUDY DESIGN AND METHODS

We retrospectively evaluated 38 patients with IDA (hemoglobin [Hb] < 10 g/dL and ferritin < 12 ng/mL or transferrin saturation [TSAT] < 16%) refractory or intolerant to oral iron therapy that necessitated transfusion support in the previous 12 months. They were treated with FCM (500-2500 mg). The primary endpoint was to evaluate the reduction of transfusion requirements (red blood cell [RBC] units) after FCM treatment.

RESULTS

The median age of the cohort was 78 years, with a male:female ratio of 22:16. Before FCM treatment a median of 6 RBC units had been transfused. At the treatment (T0) the median value of Hb was 8.7 g/dL, the TSAT 6%, and ferritin 12 ng/mL. The median FCM dose was 1000 mg. At 5 weeks from T0 the median Hb level was 11 g/dL, with a median increase of 2.4 g/dL. With a median follow-up of 326 days, the median transfusion requirement was 0 RBC units, significantly lower than before T0 (p < 0.001). Overall 17 patients still necessitated transfusion support. Twenty-three patients needed retreatment with FCM for recurrence of IDA: 10 of them obtained a response again. The percentage of transfusion-independent patients at median follow-up was equal to 52%.

CONCLUSION

In patients with IDA secondary to CBL, FCM significantly reduces the need of transfusions and achieves transfusion independence in half of the cases.

Iron deficiency or anemia of inflammation? : Differential diagnosis and mechanisms of anemia of inflammation

Iron deficiency and immune activation are the two most frequent causes of anemia, both of which are based on disturbances of iron homeostasis. Iron deficiency anemia results from a reduction of the body’s iron content due to blood loss, inadequate dietary iron intake, its malabsorption, or increased iron demand. Immune activation drives a diversion of iron fluxes from the erythropoietic bone marrow, where hemoglobinization takes place, to storage sites, particularly the mononuclear phagocytes system in liver and spleen. This results in iron-limited erythropoiesis and anemia. This review summarizes current diagnostic and pathophysiological concepts of iron deficiency anemia and anemia of inflammation, as well as combined conditions, and provides a brief outlook on novel therapeutic options.

Efficacy and safety of iron isomaltoside (Monofer(®)) in the management of patients with iron deficiency anemia

New intravenous (IV) iron preparations should ideally be capable of delivering a wide dosing range to allow iron correction in a single or low number of visits, a rapid infusion (doses up to 1,000 mg must be administered over more than 15 minutes and doses exceeding 1,000 mg must be administered over 30 minutes or more), and minimal potential side effects including low catalytic/labile iron release with minimal risk of anaphylaxis. Furthermore, they should be convenient for the patient and health-care professional, and cost effective for the health-care system. The intention behind the development of iron isomaltoside (Monofer(®)) was to fulfill these requirements. Iron isomaltoside has been shown to be effective in treating iron deficiency anemia across multiple therapeutic patient groups and compared to placebo, IV iron sucrose, and oral iron. Iron isomaltoside consists of iron and a carbohydrate moiety where the iron is tightly bound in a matrix structure. It has a low immunogenic potential, a low potential to release labile iron, and does not appear to be associated with clinically significant hypophosphatemia. Due to the structure of iron isomaltoside, it can be administered in high doses with a maximum single dosage of 20 mg/kg body weight. Clinical trials and observational studies of iron isomaltoside show that it is an effective and well-tolerated treatment of anemia across different therapeutic areas with a favorable safety profile.

A fast-track anaemia clinic in the Emergency Department: feasibility and efficacy of intravenous iron administration for treating sub-acute iron deficiency anaemia

BACKGROUND

Clinically significant anaemia, requiring red blood cell transfusions, is frequently observed in Emergency Departments (ED). To optimise blood product use, we developed a clinical protocol for the management of iron-deficiency anaemia in a fast-track anaemia clinic within the ED.

MATERIALS AND METHODS

From November 2010 to January 2014, patients presenting with sub-acute, moderate-to-severe anaemia (haemoglobin [Hb] <11 g/dL) and confirmed or suspected iron deficiency were referred to the fast-track anaemia clinic. Those with absolute or functional iron deficiency were given intravenous (IV) ferric carboxymaltose 500-1,000 mg/week and were reassessed 4 weeks after receiving the total iron dose. The primary study outcome was the haematological response (Hb≥12 g/dL and/or Hb increment ≥2 g/dL). Changes in blood and iron parameters, transfusion rates and IV iron-related adverse drug effects were secondary outcomes.

RESULTS

Two hundred and two anaemic patients with iron deficiency (150 women/52 men; mean age, 64 years) were managed in the fast-track anaemia clinic, and received a median IV iron dose of 1,500 mg (1,000-2,000 mg). Gastro-intestinal (44%) or gynaecological (26%) bleeding was the most frequent cause of the anaemia. At follow-up (183 patients), the mean Hb increment was 3.9±2.2 g/dL; 84% of patients were classified as responders and blood and iron parameters normalised in 90%. During follow-up, 35 (17%) patients needed transfusions (2 [range: 1-3] units per patient) because they had low Hb levels, symptoms of anaemia and/or were at risk. Eight mild and one moderate, self-limited adverse drug effects were witnessed.

DISCUSSION

Our data support the feasibility of a clinical protocol for management of sub-acute anaemia with IV iron in the ED. IV iron was efficacious, safe and well tolerated. Early management of anaemia will improve the use of blood products in the ED.