Management of Late Presentation Rodenticide Poisoning
For late-presenting rodenticide poisoning with established coagulopathy and bleeding, immediately administer high-dose intravenous vitamin K1 (50-100 mg or higher) along with fresh frozen plasma and cryoprecipitate, while providing aggressive supportive care for life-threatening complications. 1, 2, 3
Immediate Stabilization and Assessment
Prioritize supportive care over toxin identification - airway management, hemodynamic support with vasopressors if needed, and correction of critical vital signs take precedence before confirming the specific rodenticide type 1, 4. Contact poison control immediately for expert guidance 1.
Critical Laboratory Evaluation
- Obtain coagulation studies immediately (PT/INR will typically be beyond measurable limits in late presentations) 3
- Check for signs of bleeding complications through complete blood count and imaging as clinically indicated 5
- Monitor for metabolic derangements requiring correction 1
Antidote and Hemostatic Therapy
Vitamin K1 Administration
Acute phase dosing: Administer intravenous vitamin K1 at doses exceeding 50-100 mg for acute hemorrhagic symptoms 3. This is substantially higher than typical warfarin reversal doses due to the extremely high affinity of long-acting anticoagulant rodenticides (LAARs) for vitamin K epoxide reductase 3.
Maintenance phase: After initial stabilization, transition to oral vitamin K1 at 100 mg daily, which is the most frequently required dose to suppress rebound coagulopathy 3. The maintenance dose should be gradually decreased over time (10-120 mg/day) as coagulation parameters improve 6.
Duration: Treatment courses average 168 days but can be prolonged due to the long half-life of second-generation rodenticides 3. Continue monitoring coagulation studies at 48-72 hour intervals initially, then adjust frequency based on stability 7.
Blood Product Support
- Administer fresh frozen plasma and cryoprecipitate along with vitamin K1 to provide immediate clotting factors 2
- Consider recombinant factor VIIa or prothrombin complex concentrate as adjunctive hemostatic therapy in life-threatening hemorrhage 3
Management of Specific Complications
Intracranial Hemorrhage
This is the most lethal complication requiring immediate neurosurgical consultation 3, 5. Management includes:
- Aggressive vitamin K1 infusion with blood product support 5
- Dehydrating agents to reduce intracranial pressure 5
- EEG monitoring for non-convulsive seizures in patients with altered mental status 1
- Benzodiazepines for seizures or agitation 1
Other Bleeding Sites
Mucocutaneous bleeding and hematuria are the most common presentations 3. Monitor for bleeding from multiple sites including gastrointestinal, genitourinary, and soft tissues 2.
Critical Pitfalls to Avoid
Do NOT delay supportive care while awaiting rodenticide identification - treatment must begin immediately based on clinical presentation 1.
Do NOT administer vitamin K prophylactically before coagulopathy is documented in patients without symptoms or significant exposure 7.
Do NOT use activated charcoal, ipecac, or gastric lavage in late presentations - these are ineffective once absorption has occurred and may delay definitive care 1, 7.
Watch for rebound coagulopathy - LAARs have extremely long half-lives and high VKOR affinity, causing bleeding to recur after initial treatment if vitamin K1 is discontinued prematurely 3. This distinguishes LAAR poisoning from warfarin overdose.
Monitor for paradoxical thrombosis - rare thrombotic complications have been reported both from the rodenticide itself and as a complication of aggressive hemostatic therapy 3.
Special Considerations
Consider phenobarbital to expedite LAAR metabolism in severe, refractory cases 3. Medical toxicology consultation is recommended for complex presentations 1.
The maintenance dose is not related to the initial toxicant concentration but rather to the duration of treatment, with gradual dose reduction over weeks to months 6.