What is the appropriate management and treatment for a patient who has ingested rat cake (rodenticide bait)?

Rat Cake (Rodenticide) Poisoning Management

Immediate Actions

Contact poison control immediately (1-800-222-1222 in the US) and prioritize supportive care over identifying the specific rodenticide type—focus on airway management, hemodynamic support, and correcting critical vital signs before confirmation of the toxin. 1, 2

Life-Threatening Presentations

• Activate EMS immediately if the patient exhibits sleepiness, seizures, difficulty breathing, or vomiting after rodenticide exposure 3, 2
• Secure the airway early if there is CNS depression, loss of protective reflexes, or respiratory compromise 2, 4
• Establish IV access and correct hemodynamic instability before pursuing specific antidote therapy 2

What NOT to Do

Critical Pitfalls to Avoid

• Do NOT delay supportive care while awaiting rodenticide identification—treatment must begin immediately based on clinical presentation 1, 2
• Do NOT administer activated charcoal, ipecac, or perform gastric lavage in presentations beyond 1-2 hours post-ingestion, as these are ineffective once absorption has occurred and only delay definitive care 3, 1, 2, 5
• Do NOT give milk or water for dilution unless specifically advised by poison control—there is insufficient evidence of benefit and it may cause emesis and aspiration 3, 2
• Do NOT administer vitamin K prophylactically before coagulopathy is documented in asymptomatic patients without significant exposure 1, 5

Risk Stratification and Monitoring

Low-Risk Patients (Can Be Observed at Home)

• Unintentional ingestion of <1 mg active ingredient (includes practically all unintentional pediatric ingestions in children <6 years) can be safely observed at home without laboratory monitoring 5
• No routine INR measurement is necessary for young children with typical unintentional exposures 6

Moderate-Risk Patients (Require Outpatient Monitoring)

• Unintentional ingestion of ≥1 mg active ingredient in asymptomatic patients should have coagulopathy evaluation at 48-72 hours post-exposure 5
• Patients on therapeutic anticoagulants who ingest any dose should have baseline prothrombin time measured, then repeated at 48-72 hours 5
• If INR is normal at 36-48 hours post-exposure, even with long-acting formulations, no further action is required 6

High-Risk Patients (Require Emergency Department Evaluation)

• Any suspected self-harm, abuse, misuse, or malicious administration—refer immediately regardless of reported dose 5
• Any symptoms of bleeding or bruising—refer immediately regardless of reported dose 5
• Chronic ingestion—refer immediately for evaluation of intent and potential coagulopathy 5

Management of Established Coagulopathy

For Active Bleeding

Administer prothrombin complex concentrate 50 units/kg (preferred), OR recombinant activated factor VII 1.2-4.8 mg, OR fresh frozen plasma 15 mL/kg if concentrate unavailable, PLUS phytomenadione (vitamin K1) 10 mg IV (100 mcg/kg for children). 6, 7

For Elevated INR Without Active Bleeding

• INR <4.0: No treatment required 6
• INR ≥4.0: Administer phytomenadione 10 mg IV 6

Long-Term Management of Anticoagulant Rodenticide Poisoning

• Acute hemorrhagic symptoms often require IV vitamin K1 in excess of 50-100 mg 2, 8
• Chronic maintenance typically requires 100 mg PO vitamin K1 daily to suppress coagulopathy 8
• Treatment courses average 168 days for long-acting anticoagulant rodenticides 8
• Monitor for metabolic derangements requiring immediate correction 1, 2

Important caveat: Normalization of INR alone is insufficient to discontinue vitamin K1 treatment—over half of patients may have serum rodenticide concentrations above safe levels (>10 ng/mL) despite normal INR, risking symptom recurrence 9

Management of Specific Complications

Intracranial Hemorrhage

• Administer benzodiazepines for seizures or agitation 1, 2
• Perform EEG monitoring for non-convulsive seizures in patients with altered mental status 1, 2

Rebound Coagulopathy

• Long-acting anticoagulant rodenticides have extremely high affinity for vitamin K epoxide reductase compared to warfarin, characterized by rebound coagulopathy after initial treatment 8
• Phenobarbital has been used to expedite rodenticide metabolism in severe cases 8

When to Consult Medical Toxicology

• Complex presentations with multiorgan bleeding 1, 2
• Late presentations with established coagulopathy and bleeding 1, 2
• Prolonged coagulopathy requiring extended treatment courses 1

Decontamination

• Remove all contaminated clothing and avoid self-contamination when handling the patient 4
• For dermal exposures, wash skin with mild soap and water 5
• For chemical powder exposure, brush off with gloved hand before washing 3