Intravenous iron overdose: treat the patient not the number

Abstract

Iron overdose in its severest form is associated with fulminant hepatic failure and death. Indications for deferoxamine include a serum iron concentration greater than 500 mcg/dL. We present a case of an intravenous iron overdose to demonstrate the limitations of focusing solely on serum concentrations. A 50-year-old woman received a five-fold overdose of intravenous iron sucrose due to a medication error. Her only complaints were mild dizziness and abdominal pain. Her iron concentration 1 h after the iron infusion was 1301 mcg/dL. Due to the lack of vomiting, normal vital signs, and a normal anion gap, the treating team withheld deferoxamine and observed the patient. Her symptoms resolved spontaneously, her laboratory studies remained normal and deferoxamine was never administered. Iron sucrose is a large molecular weight compound (30,000-100,000 Daltons) designed to release iron slowly. We suspect the elevated iron concentration included iron that was complexed to carbohydrate and therefore not toxic. Clinicians need to know that intravenous iron complexed to carbohydrates may lead to serum concentrations that do not correlate with the degree of toxicity expected following iron salt ingestion. The decision to initiate chelation should depend on the patient's clinical and laboratory findings.

The Toxic Influence of Excess Free Iron on Red Blood Cells in the Biophysical Experiment: An In Vitro Study

“…Overload of free iron in the blood has different origins: chronic iron overload is a common complication of repeated packed red blood cell (pRBC) transfusions [ 1 , 4 – 6 ]; disorders of iron metabolism and chronic iron overload are observed in a number of acute and chronic inflammatory diseases and in acute respiratory distress syndrome [ 7 , 8 ]; cell-free hemoglobin can become a source of excess free iron, arising under the action of hemolytic poisons [ 9 ], sickle cell anemia [ 10 ], hemodialysis [ 11 ], cardiac bypass [ 12 ], pulmonary arterial hypertension [ 13 , 14 ], and sepsis [ 15 – 18 ], with phagocytosis of damaged RBCs [ 19 , 20 ], hereditary hemochromatosis [ 21 ], and viral diseases [ 22 – 25 ], including SARS-CoV-2 [ 8 , 26 , 27 ]. Serious toxic effects were observed in a number of extreme cases [ 28 – 30 ].…”