Anticoagulant Rodenticide Poisoning: Management

Introduction

Anticoagulant rodenticides are widely used to kill rats and other rodents by preventing blood clotting. Anticoagulants block or prevent the liver's vitamin K activation, an essential component of blood clotting factors. Exposure to these rodenticides can occur at home, during occupational use, or by suicidal attempts. Bromadiolone is an anticoagulant primarily used to kill or eradicate rodents in a single feeding. These rodenticides effectively control the rodent population worldwide but can also cause unnecessary exposure to humans and other species. Treatment options for poisoning from anticoagulant rodenticides are available to minimize the fatal risks.

What Are the Clinical Signs of Anticoagulant Rodenticide Poisoning?

In Humans:

• Blood in stool.

• Blood in the urine.

• Nose bleeding.

• Pale-colored skin.

• Hypotension (low blood pressure).

• Vomiting in blood.

• Shortness of breath.

• Chills.

• Convulsions.

• Bleeding and bruising under the skin.

• Altered mental status.

• Lethargy.

• Confusion.

• Bleeding in the brain.

• Shock.

In Animals:

• Weakness.

• Epistaxis (bleeding from the nose).

• Cavitary (cavity or empty space-example lungs) bleeding.

• Lethargy.

• Hematemesis (vomiting blood).

• Tachycardia (increased heart rate).

• Seizures (epilepsy).

• Hematuria (blood in urine).

• Hypovolemia (low liquid part in the blood).

• Melena (dark stools with or without blood).

• Pharyngeal death.

• Sudden death.

What Are the Different Types of Rodenticides Available?

There are various types of rodenticides used.These include:

Anticoagulant Rodenticides:

• Warfarin.

• Superwarfarin (long-acting anticoagulant rodenticides).

• Bromadiolone.

• Chlorophacinone.

• Difethialone.

• Brodifacoum.

Non-Anticoagulant Rodenticides:

• Strychnine.

• Bromethalin.

• Cholecalciferol.

• Thallium.

• Zinc phosphide.

What Are the Adverse Effects of Rodenticides on Human Health?

• Hemorrhage- Warfarin anticoagulant present in rodenticides can cause severe internal bleeding and lead to anemia (reduced blood cells). Bleeding also occurs in the brain, causing agitation, mental confusion, and lethargy in a person.

• Pulmonary Effects- Rodenticide exposure, especially zinc phosphide, causes breathing difficulties, cough, and chest tightness in a person. In addition, it fills the lung with fluid causing pulmonary edema.

• Liver Failure- Initially, very mild symptoms occur due to rodenticide exposure, like low levels of bilirubin and liver enzymes in the body. However, this can further aggravate, causing coagulopathy and liver failure.

• Kidney Dysfunction- Rat poison can affect kidney functioning by initially causing acute tubular necrosis of the kidney and eventually causing acute renal failure.

• Cardiac Effects- Rat poison also leads to irregular heartbeats and weak heart muscles, causing cardiomegaly. It also leads to tachycardia, hypotension, cardiogenic shock, and erythema.

• Central Nervous System Effects- Strychnine rodenticide can cause severe convulsions after a few minutes of ingestion. Due to prolonged internal bleeding, blood volume decreases, causing shock in some cases. In addition, hallucinations, psychosis, and confusion occur with rodenticide poisoning, which leads to coma.

How Is Anticoagulant Rodenticide Poisoning Diagnosed?

Diagnosis of anticoagulant rodenticide poisoning is made in the following ways:

In Humans:

• Prothrombin time increases.

• Activities of vitamin K-dependent factors (II, IIV, X, IX) are also reduced, but factor V activities remain normal.

• Activated partial prothrombin time is prolonged.

• Anemia (mild to moderate) is also present.

• Anticoagulant rodenticide poisoning is also diagnosed in plasma by assays in the laboratory.

• Chest X-rays, ECGs (electrocardiograms), and endoscopies are also done for diagnosis.

In Animals:

• Prolonged prothrombin time and thrombin time suggest toxicity due to anticoagulant rodenticides.

• Thrombocytopenia and anemia are usually mild to moderate.

• Serum, gastric content, and plasma analysis confirm the poisoning.

• Urine and blood samples are also examined.

• The veterinarian also takes chest X-rays.

What Is the Treatment for Anticoagulant Rodenticide Poisoning?

In Humans:

• First-line treatment is given by eliminating the airway or breathing obstruction, and oxygen support is provided. In severe cases, mechanical ventilation is also needed.

• Blood transfusion is also done, which contains red blood cells and clotting factors to help blood clotting.

• Activated charcoal is also given to a person to absorb the poison in the body and decontaminate the gastrointestinal tract. This treatment is done within an hour of drug ingestion for the effectiveness and safety of a person.

• As an antidote, Vitamin K1 therapy is given through an intravenous route because anticoagulant rodenticides block the vitamin K enzyme, which helps in blood clotting. This therapy thus reverses the action of the poison, which prevents blood clotting.

• Laxatives are also given to a person to remove the poison quickly from the body.

• Other symptoms are also treated with specific medication and treatment procedures.

In Animals:

• Vitamin K1 is also given to animals post-rodenticide poisoning for treatment. It can be given subcutaneously or orally, depending on the condition and drug toxicity levels. Oral doses are mostly given to eliminate hematoma formation with subcutaneous doses.

• Whole blood and frozen plasma transfusion are also done to initiate coagulation as needed.

• Proper monitoring of prothrombin time, thromboplastin time, and protein concentration are also done with supportive treatment such as oxygen therapy.

How to Prevent Anticoagulant Rodenticide Poisoning?

• Anticoagulant rodenticides or rat poison must be kept away from the reach of children and pets in a cool, dry place.

• These rodenticides must be handled with care, and always use protective gear like a mask, eyewear, and gloves while using rat poison and dead rodents.

• Cleaning the area with disinfectant and washing hands properly after using the rat poison to avoid the risk of exposure.

• Using rat traps. This can minimize the risk of exposure to rodenticides or rat poison.

• Seeking medical advice immediately in case of accidental or intentional ingestion of anticoagulant rodenticides.

What Are the Alternatives Available for Rodenticides?

Using rodenticides at home to kill rats or mice is not a safe practice and poses a threat of exposure to children and pets at home. Therefore using secure methods is advisable for this purpose which may include:

• Live traps.

• Repellants.

• Snap traps.

• Zap traps.

Conclusion

Anticoagulant rodenticides play a vital role in controlling the rodent population worldwide. However, rodents affect agriculture and significantly harm human health, causing various diseases. Anticoagulant rodenticides are very helpful in killing rodents, but their use can cause intoxication and exposure risks to other species, including humans. Although antidote therapy is available for anticoagulant rodenticide poisoning, the hazard risk is not fatal. The intoxication of rodenticides in humans and other species is still evident, but the risk factors have been mitigated by taking various safety and precautionary measures worldwide.