Emesogens

Emesogens are chemical compounds that induce vomiting, primarily used in medical contexts to treat poisoning or overdose. Their mechanism of action typically involves stimulating the chemoreceptor trigger zone (CTZ) in the brain, which is responsible for triggering the vomiting reflex. This process helps expel potentially harmful substances from the gastrointestinal tract before they can be absorbed into the bloodstream.

The most commonly used emetic agent is **syrup of ipecac**, derived from the root of the ipecacuanha plant (*Cephaelis ipecacuanha*). Historically, it has been a standard treatment for ingested poisonings, particularly in emergency settings. However, its use has declined in many regions due to advancements in medical care, such as activated charcoal administration and improved diagnostic techniques. Modern medical guidelines often recommend against its use in acute poisoning cases, as delayed gastric emptying or aspiration risks may outweigh its benefits.

Other emetic substances, such as hydrogen peroxide or apomorphine, have been used historically but are less common today. Apomorphine, for example, acts centrally by stimulating dopamine receptors in the CTZ, while hydrogen peroxide induces vomiting through direct irritation of the stomach lining. In veterinary medicine, emetics like apomorphine or xylazine are sometimes employed to treat poisoning in animals.

While emetics can be life-saving in certain situations, their use requires careful consideration. Improper administration may lead to complications, including dehydration, electrolyte imbalances, or aspiration pneumonia. As a result, their application is now generally limited to specific protocols under medical supervision. In most cases, modern emergency care focuses on preventing absorption rather than inducing vomiting.