Decreased Clinical Toxicity and Two-Phase Elimination Kinetics Observed After Intravenous Iron Sucrose Overdose

Management of oral iron overdoses is well-established, but there is limited literature regarding intravenous iron sucrose overdoses. Indications for administering deferoxamine after oral iron overdoses include clinical signs and symptoms of toxicity, along with a serum iron concentration ≥ 500 microg/dL. Reported signs and symptoms of iron sucrose overdose do not appear to correlate with those of oral iron overdoses.

We present a case of intravenous iron sucrose overdose in a clinically well-appearing patient with a presenting serum iron concentration that was several times higher than the usual threshold concentration for initiating deferoxamine treatment. A 21-year-old woman presented to the emergency department after an accidental intravenous iron sucrose overdose. The patient received a home infusion of 1000 mg iron sucrose, which was five times the prescribed dose. Her presenting serum iron concentration was 1799 microg/dL, with bicarbonate and anion gap both within normal limits and an unremarkable physical examination. Because she did not have evidence of severe iron toxicity, she was treated supportively and deferoxamine was not administered. Her serum iron concentration decreased below the toxic range over the next 14 h, and she was discharged home the next day. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This patient was managed successfully with expectant care alone, suggesting that iron sucrose overdose has much lower toxicity than oral iron salt overdose. This discrepancy between measured iron concentrations and clinical presentation may be explained by the elimination kinetics of iron sucrose having separate redistribution and elimination phases.