What is the potential risk of a 1-year-old infant (weight 10 kg) ingesting a single Ferrous sulfate (iron supplement) 325 mg pill?

Glipizide 5 mg is the Most Life-Threatening Single Pill Ingestion

A single 5 mg glipizide tablet poses the greatest immediate mortality risk for a 10 kg infant due to severe, prolonged, and unpredictable hypoglycemia that can cause seizures, permanent neurological damage, and death.

Why Glipizide is Most Dangerous

Mechanism of Toxicity

• Sulfonylureas like glipizide cause profound hypoglycemia by stimulating pancreatic insulin release, with effects lasting 12-24 hours or longer in children
• A single adult-dose tablet can cause life-threatening hypoglycemia in a small child, with symptoms including seizures, loss of consciousness, and potential brain injury
• The hypoglycemia is often refractory to treatment and requires prolonged hospitalization with continuous glucose monitoring and infusion

Dose-Toxicity Relationship

• Any sulfonylurea ingestion in a young child should be considered potentially lethal
• The 5 mg dose represents a massive relative overdose for a 10 kg infant (0.5 mg/kg), far exceeding any therapeutic pediatric dosing

Why Other Options Are Less Immediately Life-Threatening

Ferrous Sulfate 325 mg (65 mg Elemental Iron)

• This represents 6.5 mg/kg of elemental iron for a 10 kg child 1
• Acute iron ingestions of more than 60 mg/kg are considered potentially serious 2
• This single tablet ingestion falls well below the 60 mg/kg threshold for severe toxicity 2
• While iron toxicity can be fatal at very high doses (>100-390 mg/kg documented in fatal cases), a single 325 mg tablet is unlikely to cause death 2, 3, 4
• Symptoms would include gastrointestinal distress, but severe systemic toxicity, shock, and multi-organ failure typically require much larger ingestions 2, 5

Acetylsalicylic Acid 325 mg

• This represents 32.5 mg/kg for a 10 kg child
• While toxic, a single tablet is below the threshold for severe salicylate toxicity (typically >150 mg/kg for severe poisoning)
• Would cause gastric irritation and metabolic disturbances, but single-tablet ingestion rarely causes death

Acetaminophen 500 mg

• This represents 50 mg/kg for a 10 kg child
• Toxic dose is typically >150 mg/kg for hepatotoxicity risk
• A single 500 mg tablet is below the threshold for severe liver injury
• Hepatotoxicity develops over days, allowing time for antidotal treatment with N-acetylcysteine

Clinical Pitfalls

Common Misconception About Iron

• While iron is frequently cited as dangerous in pediatric ingestions, the dose matters critically 2
• A single standard ferrous sulfate tablet (325 mg = 65 mg elemental iron) in a 10 kg child does not reach the >60 mg/kg threshold for serious toxicity 2
• Multiple tablets would be required to reach potentially fatal doses

Why Sulfonylureas Are Underrecognized

• Hypoglycemia from sulfonylureas can be delayed in onset (up to 24 hours)
• Effects are prolonged and may require days of hospitalization with continuous dextrose infusion
• Even asymptomatic children require extended observation (minimum 24 hours)
• Neurological damage from hypoglycemia can be permanent

Management Priorities for Glipizide Ingestion

• Immediate blood glucose monitoring
• Prophylactic dextrose administration even if initially normoglycemic
• Admission for minimum 24-hour observation with frequent glucose checks
• Octreotide may be required for refractory hypoglycemia
• Activated charcoal if presenting within 1 hour 6