How does rat poison affect humans? - briefly
Ingesting rodent bait introduces anticoagulant compounds that inhibit vitamin K recycling, leading to uncontrolled internal bleeding. Symptoms emerge from a few hours to several days and can be lethal without immediate medical intervention.
How does rat poison affect humans? - in detail
Rodent anticoagulant baits contain chemicals such as warfarin, bromadiolone, brodifacoum, and difenacoum. These agents inhibit vitamin K‑dependent clotting factors (II, VII, IX, X) by blocking the enzyme vitamin K epoxide reductase. The resulting coagulopathy can be life‑threatening when sufficient dose enters the bloodstream.
Absorption and distribution
Ingestion is the primary route; dermal contact may contribute if the skin is broken. After swallowing, the toxin is absorbed in the gastrointestinal tract, reaches peak plasma concentration within 2–6 hours, and binds to plasma proteins, distributing throughout the body. Lipophilic compounds (e.g., brodifacoum) accumulate in the liver and persist for weeks to months, extending the risk of delayed bleeding.
Clinical manifestations
- Early (12–48 h): Nausea, vomiting, abdominal pain, loss of appetite.
- Intermediate (2–5 days): Hematuria, epistaxis, gingival bleeding, easy bruising, hematomas.
- Late (>5 days): Intracranial hemorrhage, gastrointestinal bleeding, pulmonary hemorrhage, severe anemia.
The severity correlates with the amount ingested, the specific anticoagulant, and individual susceptibility (e.g., pre‑existing liver disease or concurrent vitamin K antagonists).
Laboratory findings
- Prolonged prothrombin time (PT) and international normalized ratio (INR).
- Extended activated partial thromboplastin time (aPTT).
- Decreased levels of clotting factors II, VII, IX, X.
- Normal platelet count and function.
Management
- Decontamination
- Activated charcoal (50 g) within 1 hour of ingestion, repeat dosing if delayed gastric emptying is suspected.
- Anticoagulation reversal
- Intravenous vitamin K₁ (phytonadione) 10 mg every 6 hours until PT normalizes; high‑dose oral vitamin K (25 mg) may be required for long‑acting agents.
- Fresh frozen plasma (FFP) or prothrombin complex concentrate (PCC) for rapid clotting factor replacement in active bleeding.
- Supportive care
- Blood transfusion for anemia, surgical intervention for uncontrolled hemorrhage.
- Monitoring of PT/INR every 6–12 hours until stable, then weekly for several weeks due to possible rebound coagulopathy.
Prognosis
Prompt vitamin K therapy and coagulation factor replacement dramatically reduce mortality. Delayed treatment, massive ingestion, or exposure to second‑generation anticoagulants (brodifacoum, bromadiolone) carries a higher risk of fatal bleeding because of prolonged half‑lives (up to 40 days). Chronic low‑level exposure can cause subclinical coagulopathy, emphasizing the need for immediate medical evaluation after any suspected contact.
Prevention
Secure bait stations to limit accidental human contact, educate caregivers about symptoms, and maintain proper labeling and storage. Early recognition and aggressive reversal remain the cornerstone of reducing harm from rodent anticoagulant poisoning.