emetic(redirected from direct emetic)
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an agent that induces vomiting. Emetics are distinguished according to whether they act on the vomiting center in the brain (for example, apomorphine) or whether they irritate the mucous membrane of the stomach and reflexly excite the stomach’s vomiting center (ipecac or thermopsis). Emetics are used to counteract the effects of poisoning and to treat chronic alcoholism. For example, an injection of apomorphine combined with ingestion of alcohol leads to a conditioned reflex causing the taste and odor of alcohol to induce vomiting. When taken in small doses, emetics act as expectorants.