Hypophosphatemia is associated with some IV irons¹

Hypophosphatemia may go unnoticed because its clinical symptomology, such as fatigue, can overlap with iron deficiency anemia (IDA)^1,2

Severe hypophosphatemia (decreased phosphorus) can lead to serious complications¹:

General weakness and fatigue¹	Headaches¹	GI symptoms such as nausea, diarrhea, and vomiting¹	Vertigo¹
Depression¹	Paresthesias¹	Bone pain¹	Osteomalacia^3-5

General weakness and fatigue¹	Headaches¹
GI symptoms such as nausea, diarrhea, and vomiting¹	Vertigo¹
Depression¹	Paresthesias¹
Bone pain¹	Osteomalacia^3-5

The risk of hypophosphatemia may be linked to elevated FGF23 levels caused by some IV irons^6,7

FGF23 is a hormone produced in the osteocytes that acts on the kidney to regulate phosphate homeostasis⁶
Some IV irons increase levels of FGF23 (through an unknown mechanism), which can lead to hypophosphatemia^1,7

FGF23=fibroblast growth factor 23; GI=gastrointestinal.

There are more than just iron levels to consider in treating your patients with iron deficiency anemia

Hypophosphatemia and its complications should be considered when prescribing IV iron¹:

Hypophosphatemia can occur despite normal pre-IV iron dose phosphate levels⁸
Monitoring phosphate levels approximately 1 to 2 weeks post-infusion is recommended^9,10

Choose an IV iron formulation carefully—your choice can impact patient risk of hypophosphatemia¹

NEXT: FERAHEME vs Injectafer

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See hypophosphatemia data in a head-to-head study of two IV irons.

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Feraheme^® (ferumoxytol injection) Important Safety Information

WARNING: RISK FOR SERIOUS HYPERSENSITIVITY/ANAPHYLAXIS REACTIONS

Fatal and serious hypersensitivity reactions including anaphylaxis have occurred in patients receiving Feraheme. Initial symptoms may include hypotension, syncope, unresponsiveness, cardiac/cardiorespiratory arrest.

Only administer Feraheme as an intravenous infusion over at least 15 minutes and only when personnel and therapies are immediately available for the treatment of anaphylaxis and other hypersensitivity reactions.
Observe for signs or symptoms of hypersensitivity reactions during and for at least 30 minutes following Feraheme infusion including monitoring of blood pressure and pulse during and after Feraheme administration.
Hypersensitivity reactions have occurred in patients in whom a previous Feraheme dose was tolerated.

Feraheme^® (ferumoxytol injection) Important Safety Information

WARNING: RISK FOR SERIOUS HYPERSENSITIVITY/ANAPHYLAXIS REACTIONS

Fatal and serious hypersensitivity reactions including anaphylaxis have occurred in patients receiving Feraheme. Initial symptoms may include hypotension, syncope, unresponsiveness, cardiac/cardiorespiratory arrest.

Only administer Feraheme as an intravenous infusion over at least 15 minutes and only when personnel and therapies are immediately available for the treatment of anaphylaxis and other hypersensitivity reactions.
Observe for signs or symptoms of hypersensitivity reactions during and for at least 30 minutes following Feraheme infusion including monitoring of blood pressure and pulse during and after Feraheme administration.
Hypersensitivity reactions have occurred in patients in whom a previous Feraheme dose was tolerated.

Indication and Dosing

Feraheme is indicated for the treatment of iron deficiency anemia (IDA) in adult patients:

who have intolerance to oral iron or have had unsatisfactory response to oral iron or
who have chronic kidney disease (CKD)

The recommended dose of FERAHEME is an initial 510 mg dose followed by a second 510 mg dose as early as 3 days and up to 8 days later, each dose infused over at least 15 minutes while the patient is in a reclined or semi-reclined position.

Contraindications

Feraheme is contraindicated in patients with known hypersensitivity to Feraheme or any of its components or a history of allergic reaction to any intravenous iron product.

Warnings and Precautions

Hypersensitivity: In addition to the fatal and serious adverse reactions in the Boxed Warning, other adverse reactions associated with hypersensitivity have occurred (pruritus, rash, urticaria, and wheezing). Allergic reactions have occurred following the first dose or subsequent doses in patients in whom a previous dose was tolerated. Patients with a history of multiple drug allergies may have a greater risk of anaphylaxis with parenteral iron products. Carefully consider the potential risks and benefits before administering Feraheme to these patients. Elderly patients with multiple or serious co-morbidities who experience hypersensitivity reactions and/or hypotension following administration of Feraheme may have more severe outcomes.

Hypotension: Feraheme may cause clinically significant hypotension. Monitor patients for signs and symptoms of hypotension following each Feraheme administration.

Iron Overload: Excessive therapy with parenteral iron can lead to excess storage of iron with the possibility of iatrogenic hemosiderosis. Regularly monitor the hematologic response during parenteral iron therapy. Do not administer Feraheme to patients with iron overload.

Magnetic Resonance (MR) Imaging Test Interference: Administration of Feraheme may transiently affect the diagnostic ability of MR imaging. Alteration of MR imaging studies may persist for up to 3 months following the last Feraheme dose. Maximum alteration of vascular MR imaging is anticipated to be evident for 1 – 2 days following Feraheme administration.

Adverse Reactions

The most common adverse reactions (≥ 2%) are diarrhea, headache, nausea, dizziness, hypotension, constipation, and peripheral edema.

You may report an adverse event related to AMAG Pharmaceuticals’ products by calling 1-877-411-2510 or emailing [email protected]. If you prefer, you may contact the U.S. Food and Drug Administration (FDA) directly at fda.gov/medwatch or call 1-800-FDA-1088.

Please see Full Prescribing Information, including Boxed Warning.

References: 1. Zoller H, Schaefer B, Glodny B. Iron-induced hypophosphatemia: an emerging complication. Curr Opin Nephrol Hypertens. 2017;26(4):266-275. 2. Imel EA, Econs MJ. Approach to the hypophosphatemic patient. J Clin Endocrinol Metab. 2012;97(3):696-706. 3. Urbina T, Belkhir R, Rossi G, et al. Iron supplementation-induced phosphaturic osteomalacia: FGF23 is the culprit. J Bone Miner Res. 2018;33(3):540-542. 4. Bartko J, Roschger P, Zandieh S, Brehm A, Zwerina J, Klaushofer K. Hypophosphatemia, severe bone pain, gait disturbance, and fatigue fractures after iron substitution in inflammatory bowel disease: a case report. J Bone Miner Res. 2018;33(3):534-539. 5. Klein K, Asaad S, Econs M, Rubin JE. Severe FGF23-based hypophosphataemic osteomalacia due to ferric carboxymaltose administration. BMJ Case Rep. 2018. pii:bcr-2017-222851. doi:10.1136/bcr-2017-222851. 6. Liu S, Quarles LD. How fibroblast growth factor 23 works. J Am Soc Nephrol. 2007;18(6):1637-1647. 7. Wolf M, Koch TA, Bregman DB. Effects of iron deficiency anemia and its treatment on fibroblast growth factor 23 and phosphate homeostasis in women. J Bone Miner Res. 2013;28(8):1793-1803. 8. Wolf M, Chertow GM, Macdougall IC, Kaper R, Krop J, Strauss W. Randomized trial of intravenous iron-induced hypophosphatemia. JCI Insight. 2018;3(23):1-12. 9. Blazevic A, Hunze J, Boots JM. Severe hypophosphataemia after intravenous iron administration. Neth J Med. 2014;72(1):49-53. 10. Huang LL, Lee D, Troster SM, et al. A controlled study of the effects of ferric carboxymaltose on bone and haematinic biomarkers in chronic kidney disease and pregnancy. Nephrol Dial Transplant. 2018;33(9):1628-1635.