What is the treatment for rat killer paste ingestion?

Treatment of Rat Killer Paste Ingestion

Immediately contact poison control (1-800-222-1222 in the US) and prioritize supportive care over toxin identification, focusing on airway management, hemodynamic support, and correction of critical vital signs before confirming the specific rodenticide type. 1, 2

Immediate Management

Do NOT Administer These Interventions

• Do not give activated charcoal, ipecac, or perform gastric lavage in late presentations (beyond 1-2 hours), as these are ineffective once absorption has occurred and may delay definitive care 1, 2
• Do not administer milk or water for dilution unless specifically advised by poison control, as there is insufficient evidence of benefit and it may cause emesis and aspiration 1
• Do not delay supportive care while awaiting rodenticide identification—treatment must begin immediately based on clinical presentation 2

Initial Assessment and Stabilization

• Activate EMS immediately if the patient exhibits any life-threatening signs: sleepiness, seizures, difficulty breathing, or vomiting 1
• Secure airway, establish IV access, and correct hemodynamic instability before pursuing specific antidote therapy 2
• Monitor for metabolic derangements requiring immediate correction 2

Anticoagulant Rodenticide Poisoning (Most Common Type)

Modern rat poisons typically contain long-acting anticoagulant rodenticides (LAARs) like brodifacoum, bromadiolone, or difenacoum—these are "superwarfarins" with elimination half-lives of 15-36 days 3, 4, 5.

Coagulation Monitoring

• Measure INR at 36-48 hours post-exposure in all cases except young children with minimal exposure 6
• If INR is normal at 48 hours, even with long-acting formulations, no further action is required 6
• For young children with small unintentional exposures, routine INR measurement is unnecessary 6

Treatment Based on Clinical Presentation

Active Bleeding Present:

• Administer prothrombin complex concentrate (PCC) 50 units/kg as first-line hemostatic therapy 6
• Alternative: Recombinant activated factor VII 1.2-4.8 mg if PCC unavailable 6
• Last resort: Fresh frozen plasma 15 mL/kg if no concentrate available 6
• Plus phytomenadione (vitamin K1) 10 mg IV (100 mcg/kg for children) 6
• For severe hemorrhage, vitamin K1 doses of 50-100 mg IV may be required 3

Elevated INR Without Active Bleeding:

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

Long-Term Vitamin K Therapy

For significant ingestions with documented coagulopathy:

• Chronic maintenance typically requires 100 mg oral vitamin K1 daily 3
• Treatment duration averages 168 days (approximately 6 months) but may extend longer depending on the specific rodenticide 3, 5
• Monitor for rebound coagulopathy after initial treatment—this is characteristic of superwarfarin poisoning due to extremely high affinity for vitamin K epoxide reductase 3
• Do not administer vitamin K prophylactically before coagulopathy is documented in asymptomatic patients 2

Brodifacoum-Specific Considerations

• Brodifacoum levels below 10 μg/L are associated with normal coagulation profiles and may serve as a safe treatment cessation threshold 5
• Elimination half-life ranges from 15-36 days, requiring prolonged high-dose vitamin K therapy 4, 5

Management of Specific Complications

Intracranial Hemorrhage

• Administer benzodiazepines for seizures or agitation 2
• Perform EEG monitoring for non-convulsive seizures in patients with altered mental status 2
• Aggressive hemostatic therapy as outlined above 2

Pregnancy Considerations

• Aggressive vitamin K therapy can control maternal coagulopathy without apparent fetal harm 7
• Monitor for fetal hemorrhage with serial sonography 7
• Brodifacoum ingestion may cause substantial maternal hemorrhage but no documented teratogenic effects 7

Critical Pitfalls to Avoid

• Never delay supportive care while awaiting specific rodenticide identification 2
• Do not use standard warfarin dosing protocols—superwarfarins require much higher vitamin K doses and longer treatment duration 3, 4
• Do not discontinue vitamin K prematurely—rebound coagulopathy is common and may occur weeks after initial treatment 3
• Avoid activated charcoal in late presentations—it provides no benefit and delays definitive care 1, 2

When to Consult Medical Toxicology

• Complex presentations with multiorgan bleeding 2
• Late presentations with established coagulopathy 2
• Refractory coagulopathy despite appropriate vitamin K dosing 3
• Pregnancy cases 7