II. Precautions
- Iron supplements in overdosage may be lethal in children (FDA black box warning)
-
Iron toxicity after acute ingestion is difficult to gauge
- Variable effects depending on formulation (Serum Iron levels are better correlates)
- Toxic Overdoses may occur with ingestions as low as 10 to 20 mg/kg elemental iron
- Elemental iron varies by formulation (see Iron Supplementation)
- Ferrous Fumarate contains 33% elemental iron
- Ferrous Sulfate contains 20% elemental iron
- Ferrous Gluconate contains 12% elemental iron
III. Pathophysiology: Iron Toxicity
- Stage 1: Gastrointestinal (0.5 to 6 hours)
- Abdominal Pain
- Nausea and Vomiting
- Diarrhea
- Hematemesis
- Melana
- Lethargy
- Stage 2: Latent Period (6 to 24 hours)
- Metabolic Acidosis may be present
- Lethargy may be present
- Hypotension may be present
- Stage 3: Systemic Toxicity and Shock (6-72 hours)
- Cyanosis
- Hypovolemia and Hypotension (shock)
- Lactic Acidosis
- Lethargy
- Restlessness
- Disorientation to Coma
- Convulsions
- Coagulopathy
- Stage 4: Hepatic (12-96 hours)
- Hepatotoxicity (onset within 48 hours)
- Hepatic Failure
- Jaundice
- Hypoglycemia
- Coagulopathy
- Stage 5: Delayed (2-4 weeks)
- Gastric outlet obstruction or Small Bowel Obstruction (2-8 weeks)
- Pyloric scarring
IV. Labs
- See Overdose for Unknown Ingestion evaluation
-
Serum Iron levels predict severity of ingestion
- Serum Iron 300 to 500 mcg/dl
- Primarily signficant gastrointestinal symptoms with mild systemic toxicity
- Serum Iron 500 to 1000 mcg/dl
- Moderate systemic toxicity
- Serum Iron >1000 mcg/dl
- Severe toxicity and morbidity
- Serum Iron 300 to 500 mcg/dl
-
Complete Blood Count
- Leukocytosis may be present (but does not predict toxicity)
- Comprehensive Metabolic Panel (with Electrolytes, Liver Function Tests, Renal Function tests)
- Hypoglycemia may be present (but does not predict toxicity)
- Coagulation Studies (INR, PTT)
V. Management
- ABC Management
- Contact poison control
- Initial emergent supportive care for shock
- Crystalloid (NS or LR) replacement for Hypovolemia
- Transfuse pRBCs
- Correct Metabolic Acidosis
- Discuss Gastric Decontamination with poison control
- Whole Bowel Irrigation may be recommended
- Polyethylene glycol (typically via Nasogastric Tube)
- Children: 25 ml/kg/h (typically 250-500 ml/h) for 6-10 hours
- Adults: 2 L/h for 6-10 hours
- Avoid Activated Charcoal (ineffective in iron absorption)
- Deferoxamine Chelation
- Indications (once hemodynamically stable)
- Vomiting, diarhea and signs of shock
- Peak iron level >500 mcg/dl (90 mmol/L)
- Peak iron level >350 mcg/dl AND symptomatic (including persistent Vomiting)
- Pills seen on abdominal XRay
- Metabolic Acidosis
- Protocol
- Deferoxamine started at 5 mg/kg/h and observe for Hypotension over the subsequent hour
- May titrate to a maximum of 15 mg/kg/h while closely observing for Hypotension
- Some cases have used doses as high as 50 mg/kg/h in very severe Poisonings
- Obtain iron levels every 2-3 hours
- Discontinue Deferoxamine when iron level <350 mcg/dl (62 mmol/L) and asymptomatic
- Anticipate Urine Color change
- Orange red color (vin rose urine) reflects iron-deferoxamine complex excretion
- Indications (once hemodynamically stable)
VI. Prognosis
-
Serum Iron at 2-6 hours after ingestion
- Serum Iron <300 mcg/dl predicts benign course
- Serum Iron >500 mcg/dl predicts severe course
VII. References
- Gossman (2016) Emergency Medicine Oral Board Review, p. 207-9
- Okuda (2019) Emergency Medicine Oral Board Review, p. 38-43
- (2016) CALS Manual, 14th ed, I-137
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Related Studies
Concepts | Injury or Poisoning (T037) |
ICD9 | 964.0 |
ICD10 | T45.4 , T45.4X1 |
SnomedCT | 55381001 |
English | Poisoning by iron and its compounds, Iron and its compounds, Poisoning - iron compound drug, Iron + iron compound poisoning, Poisoning-iron/compounds, Poisoning by iron and its compounds NOS, Poisoning by iron compound drug, Iron and iron compound poisoning, Poisoning by iron AND/OR its compounds (disorder), Poisoning by iron AND/OR its compounds, Poisoning by iron and its compounds, NOS |
German | Vergiftung: Eisen und dessen Verbindungen, Vergiftung durch Eisen und seine Verbindungen |
Korean | 철 및 그 복합물에 의한 중독 |
Spanish | Intoxicación por hierro y sus compuestos, intoxicación por hierro Y/O sus compuestos (trastorno), intoxicación por hierro Y/O sus compuestos |
Portuguese | Intoxicação por ferro e seus compostos |
Italian | Avvelenamento da ferro e suoi composti |
French | Intoxication par le fer et ses composés |
Dutch | vergiftiging door ijzer en zijn componenten, IJzer en ijzerverbindingen |
Czech | Otrava železem a jeho sloučeninami |
Hungarian | Vas és vegyületei által okozott mérgezés |