Interventions for treating iron deficiency anaemia in inflammatory bowel disease
The Cochrane database of systematic reviews. 2021;1:Cd013529
BACKGROUND Inflammatory bowel disease affects approximately seven million people globally. Iron deficiency anaemia can occur as a common systemic manifestation, with a prevalence of up to 90%, which can significantly affect quality of life, both during periods of active disease or in remission. It is important that iron deficiency anaemia is treated effectively and not be assumed to be a normal finding of inflammatory bowel disease. The various routes of iron administration, doses and preparations present varying advantages and disadvantages, and a significant proportion of people experience adverse effects with current therapies. Currently, no consensus has been reached amongst physicians as to which treatment path is most beneficial. OBJECTIVES The primary objective was to evaluate the efficacy and safety of the interventions for the treatment of iron deficiency anaemia in people with inflammatory bowel disease. SEARCH METHODS We searched CENTRAL, MEDLINE, Embase, and two other databases on 21st November 2019. We also contacted experts in the field and searched references of trials for any additional trials. SELECTION CRITERIA Randomised controlled trials investigating the effectiveness and safety of iron administration interventions compared to other iron administration interventions or placebo in the treatment of iron deficiency anaemia in inflammatory bowel disease. We considered both adults and children, with studies reporting outcomes of clinical, endoscopic, histologic or surgical remission as defined by study authors. DATA COLLECTION AND ANALYSIS Two review authors independently conducted data extraction and 'Risk of bias' assessment of included studies. We expressed dichotomous and continuous outcomes as risk ratios and mean differences with 95% confidence intervals. We assessed the certainty of the evidence using the GRADE methodology. MAIN RESULTS We included 11 studies (1670 randomised participants) that met the inclusion criteria. The studies compared intravenous iron sucrose vs oral iron sulphate (2 studies); oral iron sulphate vs oral iron hydroxide polymaltose complex (1 study); oral iron fumarate vs intravenous iron sucrose (1 study); intravenous ferric carboxymaltose vs intravenous iron sucrose (1 study); erythropoietin injection + intravenous iron sucrose vs intravenous iron sucrose + injection placebo (1 study); oral ferric maltol vs oral placebo (1 study); oral ferric maltol vs intravenous ferric carboxymaltose (1 study); intravenous ferric carboxymaltose vs oral iron sulphate (1 study); intravenous iron isomaltoside vs oral iron sulphate (1 study); erythropoietin injection vs oral placebo (1 study). All studies compared participants with CD and UC together, as well as considering a range of disease activity states. The primary outcome of number of responders, when defined, was stated to be an increase in haemoglobin of 20 g/L in all but two studies in which an increase in 10g/L was used. In one study comparing intravenous ferric carboxymaltose and intravenous iron sucrose, moderate-certainty evidence was found that intravenous ferric carboxymaltose was probably superior to intravenous iron sucrose, although there were responders in both groups (150/244 versus 118/239, RR 1.25, 95% CI 1.06 to 1.46, number needed to treat for an additional beneficial outcome (NNTB) = 9). In one study comparing oral ferric maltol to placebo, there was low-certainty evidence of superiority of the iron (36/64 versus 0/64, RR 73.00, 95% CI 4.58 to 1164.36). There were no other direct comparisons that found any difference in the primary outcomes, although certainty was low and very low for all outcomes, due to imprecision from sparse data and risk of bias varying between moderate and high risk. The reporting of secondary outcomes was inconsistent. The most common was the occurrence of serious adverse events or those requiring withdrawal of therapy. In no comparisons was there a difference seen between any of the intervention agents being studied, although the certainty was very low for all comparisons made, due to risk of bias and significant imprecision due to the low numbers of events. Time to remission, histological and biochemical outcomes were sparsely reported in the studies. None of the other secondary outcomes were reported in any of the studies. An analysis of all intravenous iron preparations to all oral iron preparations showed that intravenous administration may lead to more responders (368/554 versus 205/373, RR 1.17, 95% CI 1.05 to 1.31, NNTB = 11, low-certainty due to risk of bias and inconsistency). Withdrawals due to adverse events may be greater in oral iron preparations vs intravenous (15/554 versus 31/373, RR 0.39, 95% CI 0.20 to 0.74, low-certainty due to risk of bias, inconsistency and imprecision). AUTHORS' CONCLUSIONS Intravenous ferric carboxymaltose probably leads to more people having resolution of IDA (iron deficiency anaemia) than intravenous iron sucrose. Oral ferric maltol may lead to more people having resolution of IDA than placebo. We are unable to draw conclusions on which of the other treatments is most effective in IDA with IBD (inflammatory bowel disease) due to low numbers of studies in each comparison area and clinical heterogeneity within the studies. Therefore, there are no other conclusions regarding the treatments that can be made and certainty of all findings are low or very low. Overall, intravenous iron delivery probably leads to greater response in patients compared with oral iron, with a NNTB (number needed to treat) of 11. Whilst no serious adverse events were specifically elicited with any of the treatments studied, the numbers of reported events were low and the certainty of these findings very low for all comparisons, so no conclusions can be drawn. There may be more withdrawals due to such events when oral is compared with intravenous iron delivery. Other outcomes were poorly reported and once again no conclusions can be made as to the impact of IDA on any of these outcomes. Given the widespread use of many of these treatments in practice and the only guideline that exists recommending the use of intravenous iron in favour of oral iron, research to investigate this key issue is clearly needed. Considering the current ongoing trials identified in this review, these are more focussed on the impact in specific patient groups (young people) or on other symptoms (such as fatigue). Therefore, there is a need for studies to be performed to fill this evidence gap.
Systematic review with network meta-analysis: comparative efficacy and tolerability of different intravenous iron formulations for the treatment of iron deficiency anaemia in patients with inflammatory bowel disease
Alimentary Pharmacology & Therapeutics. 2017;45((10):):1303-1318
BACKGROUND Iron deficiency anaemia (IDA) is a common complication of inflammatory bowel disease (IBD) associated with reduced quality of life and increased hospitalisation rates. While the best way of treating IDA in IBD patients is not clearly established, current European guidelines recommend intravenous iron therapy in IBD patients with severe anaemia or intolerance to oral iron compounds. AIM: To compare the efficacy and tolerability of different intravenous iron formulations used to treat IDA in IBD patients in a systematic review and Bayesian network meta-analysis (NMA), PROSPERO registration number: 42016046565. METHODS In June 2016, we systematically searched for studies analysing efficacy and safety of intravenous iron for IDA therapy in IBD. Primary outcome was therapy response, defined as Hb normalisation or increase ≥2 g/dL. RESULTS Five randomised, controlled trials (n = 1143 patients) were included in a network meta-analysis. Only ferric carboxymaltose was significantly more effective than oral iron [OR=1.9, 95% CrI: (1.1;3.2)]. Rank probabilities showed ferric carboxymaltose to be most effective, followed by iron sucrose, iron isomaltose and oral iron. Pooled data from the systematic review (n = 1746 patients) revealed adverse event rates of 12.0%, 15.3%, 12.0%, 17.0% for ferric carboxymaltose, iron sucrose, iron dextran and iron isomaltose respectively. One drug-related serious adverse event (SAE) each was reported for ferric carboxymaltose and iron isomaltoside, and one possibly drug-related SAE for iron sucrose. CONCLUSIONS Ferric carboxymaltose was the most effective intravenous iron formulation, followed by iron sucrose. In addition, ferric carboxymaltose tended to be better tolerated. Thus, nanocolloidal IV iron products exhibit differing therapeutic and safety characteristics and are not interchangeable.
Intravenous versus oral iron for the treatment of anemia in inflammatory bowel disease: a systematic review and meta-analysis of randomized controlled trials
Anemia is the most prevalent extraintestinal complication of inflammatory bowel disease (IBD). Our aim was to evaluate the comparative efficacy and harm of intravenous (IV) versus oral iron supplementation for correcting anemia in adult IBD patients.We conducted a systematic review and meta-analysis to integrate evidence from randomized controlled trials having enrolled adults with IBD, and comparing IV versus oral iron (head-to-head) for correcting iron-deficiency anemia. Medline, Embase, Scopus, and the Web of Science database were searched through July 2015. The Cochrane Central Register of Controlled Trials, the WHO International Clinical Trials Registry Platform, the ClinicalTrials.gov, and international conference proceedings were also investigated. Two reviewers independently abstracted study data and outcomes, and rated each trial's risk-of-bias. Pooled odds ratio (OR) estimates with their 95% CIs were calculated using fixed- and random-effects models.Five eligible studies, including 694 IBD patients, were identified. In meta-analysis, IV iron demonstrated a higher efficacy in achieving a hemoglobin rise of >2.0 g/dL as compared to oral iron (OR: 1.57, 95% CI: 1.13, 2.18). Treatment discontinuation rates, due to adverse events or intolerance, were lower in the IV iron groups (OR: 0.27, 95% CI: 0.13, 0.59). Similarly, the occurrence of gastrointestinal adverse events was consistently lower in the IV iron groups. On the contrary, serious adverse events (SAEs) were more frequently reported among patients receiving IV iron preparations (OR: 4.57, 95% CI: 1.11, 18.8); however, the majority of the reported SAEs were judged as unrelated or unlikely to be related to the study medication. We found no evidence of publication bias, or between-study heterogeneity, across all analyses. Risk of bias was high across primary studies, because patients and personnel were not blinded to the intervention.IV iron appears to be more effective and better tolerated than oral iron for the treatment of IBD-associated anemia.
Management of iron-deficiency anemia in inflammatory bowel disease: a systematic review
Anemia is the most frequent complication of inflammatory bowel disease (IBD), but anemia, mostly due to iron deficiency, has long been neglected in these patients.The aim was to briefly present the pathophysiology, followed by a balanced overview of the different forms of iron replacement available, and subsequently, to perform a systematic review of studies performed in the last decade on the treatment of iron-deficiency anemia in IBD.Given that intravenous therapies have been introduced in the last decade, a systematic review performed in PubMed, EMBASE, the Cochrane Library, and the websites of WHO, FDA, and EMA covered prospective trials investigating the management of iron-deficiency anemia in IBD published since 2004.A total of 632 articles were reviewed, and 13 articles (2906 patients) with unique content were included. In general, oral supplementation in iron-deficiency anemia should be administered with a target to restore/replenish the iron stores and the hemoglobin level in a suitable way. However, in patients with IBD flares and inadequate responses to or side effects with oral preparations, intravenous iron supplementation is the therapy of choice. Neither oral nor intravenous therapy seems to exacerbate the clinical course of IBD, and intravenous iron therapy can be administered even in active disease stages and concomitantly with biologics.In conclusion, because many physicians are in doubt as to how to manage anemia and iron deficiency in IBD, there is a clear need for the implementation of evidence-based recommendations on this matter. Based on the data presented, oral iron therapy should be preferred for patients with quiescent disease stages and trivial iron deficiency anemia unless such patients are intolerant or have an inadequate response, whereas intravenous iron supplementation may be of advantage in patients with aggravated anemia or flares of IBD because inflammation hampers intestinal absorption of iron.