Iron Poisoning

Key Features

• Most children's preparations contain 12–15 mg of iron per dose; most adult preparations contain 60–90 mg of iron per dose

• Iron is corrosive to the GI tract

• Carbonyl iron

  • Powdered form of elemental iron

  • Not as irritating to the GI tract as the iron salts, and appears to be safer

• Excessive circulating free iron has depressant effects on myocardium and on peripheral vascular resistance

Clinical Findings

• Ingestion of < 30 mg of iron per kg of body weight usually produces only mild GI upset

• Ingestion of > 40–60 mg/kg may cause

  • Vomiting

  • Hematemesis

  • Diarrhea

  • Hypotension

  • Metabolic acidosis

• Death may occur from

  • Massive fluid losses and bleeding

  • Metabolic acidosis

  • Peritonitis from intestinal perforation

  • Sepsis

• Acute liver failure may occur

Diagnosis

• Serum iron levels > 350–500 mcg/dL are potentially toxic

• Serum levels > 1000 mcg/dL usually associated with severe poisoning

• Plain abdominal radiograph may reveal radiopaque tablets

Treatment

• Treat hypotension aggressively with intravenous crystalloid solutions (0.9% saline or lactated Ringer solution)

• Perform whole-bowel irrigation to remove unabsorbed pills, particularly when intact tablets are visible on abdominal radiograph

• Activated charcoal is not effective

• For symptomatic toxicity, and particularly with markedly elevated serum iron levels (eg, > 800–1000 mcg/dL)

  • Administer 10–15 mg/kg/h of deferoxamine by constant intravenous infusion

  • Higher doses (up to 40–50 mg/kg/h) have been used in massive poisonings

  • Prolonged infusion (> 36–48 h) has been associated with acute respiratory distress syndrome