Incidence, mechanism, and consequences of IV iron-induced hypophosphatemia

AGA Clinical Practice Update on Management of Iron Deficiency Anemia: Expert Review

DESCRIPTION

In this Clinical Practice Update (CPU), we will Best Practice Advice (BPA) guidance on the appropriate management of iron deficiency anemia.

METHODS

This expert review was commissioned and approved by the AGA Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the CPUC and external peer review through standard procedures of Clinical Gastroenterology and Hepatology. These Best Practice Advice (BPA) statements were drawn from a review of the published literature and from expert opinion. Since systematic reviews were not performed, these BPA statements do not carry formal ratings regarding the quality of evidence or strength of the presented considerations. BEST PRACTICE ADVICE 1: No single formulation of oral iron has any advantages over any other. Ferrous sulfate is preferred as the least expensive iron formulation. BEST PRACTICE ADVICE 2: Give oral iron once a day at most. Every-other-day iron dosing may be better tolerated for some patients with similar or equal rates of iron absorption as daily dosing. BEST PRACTICE ADVICE 3: Add vitamin C to oral iron supplementation to improve absorption. BEST PRACTICE ADVICE 4: Intravenous iron should be used if the patient does not tolerate oral iron, ferritin levels do not improve with a trial of oral iron, or the patient has a condition in which oral iron is not likely to be absorbed. BEST PRACTICE ADVICE 5: Intravenous iron formulations that can replace iron deficits with 1 or 2 infusions are preferred over those that require more than 2 infusions. BEST PRACTICE ADVICE 6: All intravenous iron formulations have similar risks; true anaphylaxis is very rare. The vast majority of reactions to intravenous iron are complement activation-related pseudo-allergy (infusion reactions) and should be treated as such. BEST PRACTICE ADVICE 7: Intravenous iron therapy should be used in individuals who have undergone bariatric procedures, particularly those that are likely to disrupt normal duodenal iron absorption, and have iron-deficiency anemia with no identifiable source of chronic gastrointestinal blood loss. BEST PRACTICE ADVICE 8: In individuals with inflammatory bowel disease and iron-deficiency anemia, clinicians first should determine whether iron-deficiency anemia is owing to inadequate intake or absorption, or loss of iron, typically from gastrointestinal bleeding. Active inflammation should be treated effectively to enhance iron absorption or reduce iron depletion. BEST PRACTICE ADVICE 9: Intravenous iron therapy should be given in individuals with inflammatory bowel disease, iron-deficiency anemia, and active inflammation with compromised absorption. BEST PRACTICE ADVICE 10: In individuals with portal hypertensive gastropathy and iron-deficiency anemia, oral iron supplements initially should be used to replenish iron stores. Intravenous iron therapy should be used in patients with ongoing bleeding who do not respond to oral iron therapy. BEST PRACTICE ADVICE 11: In individuals with portal hypertensive gastropathy and iron-deficiency anemia without another identified source of chronic blood loss, treatment of portal hypertension with nonselective β-blockers can be considered. BEST PRACTICE ADVICE 12: In individuals with iron-deficiency anemia secondary to gastric antral vascular ectasia who have an inadequate response to iron replacement, consider endoscopic therapy with endoscopic band ligation or thermal methods such as argon plasma coagulation. BEST PRACTICE ADVICE 13: In patients with iron-deficiency anemia and celiac disease, ensure adherence to a gluten-free diet to improve iron absorption. Consider oral iron supplementation based on the severity of iron deficiency and patient tolerance, followed by intravenous iron therapy if iron stores do not improve. BEST PRACTICE ADVICE 14: Deep enteroscopy performed in patients with iron-deficiency anemia suspected to have small-bowel bleeding angioectasias should be performed with a distal attachment to improve detection and facilitate treatment. Small-bowel angioectasias may be treated with ablative thermal therapies such as argon plasma coagulation or with mechanical methods such as hemostatic clips. BEST PRACTICE ADVICE 15: Endoscopic treatment of angioectasias should be accompanied with iron replacement. Medical therapy for small-bowel angioectasias should be reserved for compassionate treatment in refractory cases when iron replacement and endoscopic therapy are ineffective.

Expert consensus guidelines: Intravenous iron uses, formulations, administration, and management of reactions

Intravenous iron has become an essential component for the treatment of iron deficiency and iron deficiency anemia. Individuals administering Intravenous iron should have knowledge in intravenous iron administration, including a pre-infusion assessment to evaluate infusion reaction risks, pre- and post-infusion monitoring, identification of and management of infusion reactions, accurate documentation of these reactions, laboratory monitoring and recognition and management of treatment-emergent hypophosphatemia. This comprehensive consensus provides step-by-step guidance and tools for practitioners to promote safe delivery of intravenous iron, recognition, and management of infusion reactions and treatment-emergent hypophosphatemia.