Can rodenticide poisoning lead to death? Is there any specific drug treatment?

Author: Qiu Zewu, Chief Physician of the Fifth Medical Center of the General Hospital of the Chinese People's Liberation Army

Reviewer: Wang Lixiang, Chief Physician, Third Medical Center, PLA General Hospital

The 10th Chairman of the Science Popularization Branch of the Chinese Medical Association

Rodenticides refer to compounds that can kill rodents (such as rats). They can be divided into three categories according to their toxicological effects: anticoagulant rodenticides, central nervous system stimulant rodenticides, and other rodenticides.

In clinical practice, cases of rodenticide poisoning are also very common. Today we will introduce two common rodenticides, anticoagulant rodenticides and central nervous system stimulant rodenticides.

Anticoagulant rodenticides are a type of chronic rodenticide. The mechanism of action of this type of rodenticide is mainly through the inhibition of vitamin K epoxide reductase, which prevents the liver from producing prothrombin and destroys the blood's coagulation function. The poisoned animals will die from bleeding. The most common anticoagulant rodenticides are brodifacoum and brodifacoum. Central nervous system stimulant rodenticides are highly toxic, have a short incubation period, and progress quickly. Common ones include tetracycline and fluoroacetamide.

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What are the symptoms of human poisoning from these two types of rodenticides? How to treat them? Will they endanger life? Let's learn about them together.

Anticoagulant rodenticides have a milder effect. Poisoning is a slow and continuous process. The toxic effects of multiple small-dose poisonings are far greater than those of a single large-dose poisoning. Symptoms are often hidden in the early stages, and are usually asymptomatic. When the body's coagulation factors are depleted, symptoms generally begin to appear 3-5 days after poisoning, or even 7 days later.

The main symptom of poisoning is bleeding. The symptoms vary depending on the site of bleeding, such as nose bleeding, bleeding gums, blood blisters on the oral mucosa, ecchymosis and petechiae on the skin mucosa, and even painless hematuria and prolonged menstruation.

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Bleeding in special areas, such as bleeding in specific areas of the cervical spine, can lead to movement disorders in the lower body and autonomic nervous system dysfunction, including difficulty in urination and defecation; bleeding in muscle tissue can cause hematoma, compress the corresponding nerves, and may make it impossible to walk.

Symptoms usually appear after taking anticoagulant rodenticides for several days. Of course, after taking a large dose orally, coagulation disorders can also occur in a short period of time. Most poisoning patients often find symptoms unconsciously, so it is easy to misdiagnose or miss the diagnosis. When the symptoms become diversified and cannot be explained by common diseases, it is possible to consider the possibility of rodenticide poisoning, especially anticoagulant rodenticide poisoning that causes bleeding in multiple parts and systems.

Generally speaking, poisoning by human anticoagulant rodenticides will not lead to death, but if treatment is not timely and the dose is large, there are cases of death. The cause of death is generally pulmonary hemorrhage and cerebral hemorrhage.

To diagnose anticoagulant rodenticide poisoning, first, the patient's medical history is used to determine whether the patient has been actively exposed to the poison, combined with clinical manifestations, such as bleeding in multiple systems and locations. Second, auxiliary examinations, such as coagulation function tests, can be used to detect coagulation dysfunction. Third, toxicology tests can be performed, and if the corresponding poisons are found in the blood and urine, a clear diagnosis can be made. This is the gold standard for diagnosis.

Vitamin K1 is a special medicine for treating anticoagulant rodenticide poisoning. If the dose is not very large, intramuscular injection of vitamin K1 can quickly stop the bleeding. If the dose is relatively large, it may be necessary to treat it with plasma and coagulation factor transfusions, and it may also be necessary to perform blood purification to help excrete the poison.

Central nervous system stimulant rodenticides are a type of convulsant poison. Rat poison, fluoroacetamide and sodium fluoroacetate are all convulsant rodenticides. The poisoning mechanism is to cause an imbalance between excitatory and inhibitory amino acids in the body, leading to overexcitement and causing paroxysmal and recurrent epileptic symptoms, that is, convulsions.

The most common rodenticide of central nervous system stimulant is strychnine, which is very stable and highly toxic. Poisoning with strychnine can cause digestive tract symptoms such as nausea, vomiting, abdominal pain, and diarrhea; the most important symptoms are nervous system symptoms such as dizziness, weakness, and convulsions. Tonic convulsions, severe convulsions, and some may cause suffocation due to vomiting, or even death.

In the first aid of strychnine poisoning, in addition to the general catharsis, vomiting, and gastric lavage, the most important thing is to control convulsions, clear the airway, prevent infection, and comprehensive supportive treatment is the most important. To control convulsions, you can use tranquilizers. If they are ineffective, you can use other anti-epileptic drugs for auxiliary treatment. Clear airway means endotracheal intubation. If the patient has difficulty breathing on his own, a ventilator may be used.

As long as the patient can get through this stage, most of them can be cured. The treatment of strychnine poisoning can currently achieve a good prognosis.