Accidental Rodenticide Ingestion in Pediatrics

Overview

"Although intentional ingestions are often associated with significant morbidity and mortality, most unintentional exposures occur in young children and result in minimal or no toxicity." — Tintinalli's Emergency Medicine

1. Anticoagulant Rodenticides (Most Common — ~80% of exposures)

Types

Clinical Features

• Patients may be asymptomatic for up to 72 hours
• Bleeding manifestations: ecchymosis, epistaxis, gingival bleeding, hematuria, menorrhagia, hemarthrosis
• Life-threatening: massive GI bleeding, intracranial hemorrhage
• PT/INR not abnormal until 48 hours post-ingestion (a normal INR at 48 hours essentially excludes significant ingestion)

Management

Warfarin Rodenticides (1st gen)

• Single small ingestion (e.g., 1–2 pellets): No treatment needed; discharge home
• Potentially toxic ingestion: Consider activated charcoal (if early)
• Baseline PT/INR → repeat at 12–24 hours
• Vitamin K₁ (phytonadione) if INR >2.0:
  • Children: 1–5 mg/day PO in 2–4 divided doses

Superwarfarins (2nd gen — most OTC products today)

• Unintentional pediatric ingestion: unlikely to cause significant toxicity; monitoring is appropriate
• Baseline INR → repeat at 24 and 48 hours
• Activated charcoal: Only if presentation within 1 hour of massive ingestion (10:1 charcoal:poison ratio; if dose unknown, use 100 g)
• Do NOT perform gastric lavage — risk of inducing GI bleeding

Antidote: Vitamin K₁ (Phytonadione)

• Only K₁ is effective (K₃ and K₄ are not effective and have toxic potential)
• Do NOT give prophylactically — only if INR is elevated
• Takes 6 hours to take effect (not for immediate reversal)
• In massive overdose: doses as high as 800 mg/day have been required; prolonged treatment may last weeks to months (given brodifacoum's ~120-day half-life)

For Active Bleeding

• Packed RBCs for blood loss
• Fresh frozen plasma (FFP) to improve coagulation
• Four-factor prothrombin complex concentrate (PCC) — first-line
• Recombinant activated factor VII — also beneficial

Disposition

• Small ingestion in a child (tasting 2–3 pellets): Discharge with outpatient follow-up at 48–72 hours for INR check
• Large intentional ingestion: Admit for at least 48 hours; check INR at minimum 48 hours post-ingestion
• Active coagulopathy: Admit until all bleeding resolves; monitor INR closely

2. Non-Anticoagulant Rodenticides (Less Common but Often Severe)

Key Pearls in Pediatric Accidental Ingestion

1. Most accidental pediatric rodenticide ingestions require only monitoring — single small ingestions of anticoagulant rodenticides rarely cause toxicity.
2. Identify the product — brand name, active ingredient, and amount ingested are critical. Call Poison Control (1-800-222-1222 in the US) immediately.
3. INR timing matters — do not check too early; a normal INR before 48 hours does not exclude significant exposure.
4. Never give activated charcoal routinely — only for large ingestions presenting within 1 hour.
5. Non-anticoagulant rodenticides are rare but can be immediately life-threatening — treat aggressively.
6. Brodifacoum has a very long half-life (~120 days); even after INR normalizes, the child may re-anticoagulate if vitamin K is stopped prematurely.