Choice of High-Dose Intravenous Iron Preparation Determines Hypophosphatemia Risk

• Published in: PloS one Vol. 11; no. 12; p. e0167146
• Main Authors: Schaefer, Benedikt, Würtinger, Philipp, Finkenstedt, Armin, Braithwaite, Vickie, Viveiros, André, Effenberger, Maria, Sulzbacher, Irene, Moschen, Alexander, Griesmacher, Andrea, Tilg, Herbert, Vogel, Wolfgang, Zoller, Heinz
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01-12-2016; Public Library of Science (PLoS)
• Subjects: Administration, Intravenous; Adult; Aged; Anemia; Anemia, Iron-Deficiency - complications; Anemia, Iron-Deficiency - diagnosis; Anemia, Iron-Deficiency - drug therapy; Anemia, Iron-Deficiency - etiology; Archives & records; Biology and Life Sciences; Biomarkers; Complications and side effects; Diagnosis; Disaccharides - administration & dosage; Disaccharides - adverse effects; Dosage and administration; Drug dosages; Drug therapy; Electronic health records; Electronic medical records; Endocrinology; Female; Ferric carboxymaltose; Ferric Compounds - administration & dosage; Ferric Compounds - adverse effects; Fibroblast growth factor; Fibroblast growth factor 23; Fibroblasts; Gastroenterology; Growth factors; Hepatology; Hospitals; Humans; Hypophosphatemia; Hypophosphatemia - diagnosis; Hypophosphatemia - epidemiology; Hypophosphatemia - etiology; Inflammatory bowel disease; Infusion; Intravenous administration; Iron; Iron deficiency; Iron deficiency diseases; Laboratories; Male; Maltose - administration & dosage; Maltose - adverse effects; Maltose - analogs & derivatives; Medical records; Medicine; Medicine and Health Sciences; Metabolism; Middle Aged; Nutrient deficiency; Nutrition research; Patients; Phosphatase; Phosphates; Phosphates - blood; Physical Sciences; Plasma; Prevalence; Prognosis; Research and Analysis Methods; Retrospective Studies; Risk; Risk factors; Transplants & implants; Austria
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0167146

Ferric carboxymaltose (FCM) and iron isomaltoside 1000 (IIM) are increasingly used because they allow correction of severe iron deficiency in a single infusion. A transient decrease in serum phosphate concentrations is a frequent side effect of FCM.
To characterize this adverse event and search for its predictors in a gastroenterology clinic patient cohort.
Electronic medical records of patients attending the University Hospital of Innsbruck were searched for the keywords ferric carboxymaltose or iron isomaltoside. Eighty-one patients with documented administration of FCM or IIM with plasma phosphate concentrations before and after treatment were included.
The prevalence of hypophosphatemia (<0.8 mmol/L) increased from 11% to 32.1% after treatment with i.v. iron. The hypophosphatemia risk was greater after FCM (45.5%) compared with IIM (4%). Severe hypophosphatemia (<0.6 mmol/L) occurred exclusively after FCM (32.7%). The odds for hypophosphatemia after i.v. iron treatment were independently determined by baseline phosphate and the choice of i.v. iron preparation (FCM vs. IIM-OR = 20.8; 95% CI, 2.6-166; p = 0.004). The median time with hypophosphatemia was 41 days, but prolonged hypophosphatemia of ≥ 2 months was documented in 13 of 17 patients in whom follow-up was available. A significant increase in the phosphaturic hormone intact FGF-23 in hypophosphatemic patients shows that this adverse event is caused by FCM-induced hormone dysregulation.
Treatment with FCM is associated with a high risk of developing severe and prolonged hypophosphatemia and should therefore be monitored. Hypophosphatemia risk appears to be substantially lower with IIM.