Bromethalin

Bromethalin is a potent rodenticide that is lethal to both mammals and birds. It was developed and introduced in the United States in 1985 as an alternative to anticoagulant rodenticides, due to the increasing resistance of rats and mice to these substances.

Mechanism of Action

Bromethalin's mode of action is by uncoupling oxidative phosphorylation in the mitochondria of the central nervous system. This leads to a decrease in adenosine triphosphate (ATP) production, causing a disruption in the normal functioning of the neurons. This results in an increase in intracellular sodium and water, causing cellular edema and eventually leading to cerebral edema, increased intracranial pressure, and death.

Toxicity

Bromethalin is highly toxic to mammals and birds, with a lethal dose for rats being 2.38 mg/kg body weight. Symptoms of bromethalin poisoning in mammals include ataxia, paralysis, seizures, and death. There is no known antidote for bromethalin poisoning, and treatment is largely supportive and symptomatic.

Use and Regulation

Bromethalin is used primarily as a rodenticide, and is available in several forms including pellets, seed, and bait blocks. It is regulated by the Environmental Protection Agency (EPA) in the United States, and its use is restricted to certified applicators.

See Also

• Rodenticide
• Pesticide
• Toxicology