Kids accidentally ingest medicines. In the Peds ED we are rightfully worried about opiates, BP meds, acetaminophen, and diabetes drugs (among many others) but we shouldn’t overlook the potential dangers that come with iron ingestion. Let’s take a look shall we?

Why do humans need iron?

Iron is a part of lots and lots of proteins and enzymes especially hemoglobin, myoglobin, and cytochromes.

What is the normal dose?

For iron deficiency anemia children generally get 4 to 6 mg/kg/day.

How much do normal people have in their body?

Normal serum iron levels generally range from 65 to 175 mcg/dL.

Is it a common severe ingestion?

Less so than in the past as a result of improved packaging

What are the toxicologic effects and toxic dose range?

Iron is a cellular poison and it is also directly corrosive to the GI mucosa. Ingestions of <40 mg/kg generally don’t lead to major toxicity, although mild GI irritation may develop. With peak level >300 mcg/dL Mild symptoms are likely to occur. Peak concentrations > 500 mcg/dL generally cause severe symptoms. Certainly symptoms may not correlate with peak concentration if the patient presents a while after the ingestion.

Would you care to elaborate on the differences between mild, moderate and severe toxicity?

Sure.

Mild to Moderate

Vomiting and diarrhea may occur within 6 hours of ingestion. if you don’t see this then it is unlikely the patient took a toxic dose. You might not need to get a level according to some toxicologists.

Severe

This is where it gets dicey. Again, with levels >500 mcg/dL you can see significant vomiting and diarrhea, lethargy, metabolic acidosis, shock, GI hemorrhage, coma, seizures, hepatotoxicity, and late onset GI strictures. There are 5 phases of iron toxicity.

PHASE I (0.5 to 2 hours) includes vomiting, hematemesis, abdominal pain, diarrhea, hematochezia, lethargy, shock (from GI bleed), acidosis, and coagulopathy. GI tract necrosis occurs from the direct effects of iron.

PHASE II (>2 but <12 hours) apparent recovery

PHASE III (2 to 12 hours after phase I) Profound shock, severe metabolic acidosis, CNS depression, cyanosis, and fever.

PHASE IV (2 to 4 days) Hepatotoxicity perhaps due to direct action of iron on mitochondria. This is when the hepatic profile can be the most helpful. Acute lung injury may also be seen.

PHASE V (days to weeks) GI scarring and strictures.

That sounds bad. When and how do I treat iron ingestions?

Mild to moderate toxicity (GI symptoms) is treated with supportive care with IV fluids and antiemetics. Activated charcoal is not effective. Get serum iron levels 4 to 6 hours after the initial ingestion in symptomatic patients – then repeat in 2 to 4 hours. Patients who develop metabolic acidosis or are clinically worsening despite IV fluids should be treated with chelation (see more below). Also get an abdominal X-Ray to look for radioopaque iron tablets. If you see a lot of tablets consider whole bowel irrigation with polyethylene glycol. In sever ingestions you may want to talk to GI about endoscopic removal if there are numerous tablets still in the stomach.

Lots of iron tablets (from lifeinthefastlane.com)

Chelation with deferoxamine is warranted for severe toxicity (shock, acidosis, GI hemorrhage, and lethargy or coma) and/or concentrations > 500 mcg/dL. Deferoxamine is the chelating agent du jour. You give it IV at 15 mg/kg/hour to start and can titrate up to 45 mg/kg/hour for patients with severe poisoning. The main risk is hypotension, which deferoxamine is good at causing. Infusions greater than 24 hours are associated with acute lung injury – and therefore its a good idea to stop prior to that. Interestingly chelation with deferoxamine also increases the risk of Yersinia enterocolitica sepsis. Additional therapies include magnesium hydroxide (5 mg per gram of elemental iron ingested) and pRBC transfusions.

Can I send some iron ingestions home without doing anything?

Accidental ingestions of < 40 mg/kg of elemental iron in patients who have no or only mild GI symptoms (self limited vomiting or diarrhea) can be watched at home. Patients with more than mild symptoms, ingestion of > 40 mg/kg, or patients with intentional ingestions should be seen in the ED. If the symptoms improve, and the 4 hour level is < 300 mcg/dL they can go home. Certainly patients with hypotension, metabolic acidosis, GI hemorrhage, altered mental status, or is in need of chelation requires admission. It is always a good idea to call your local poison center.