Which of the following is an example of a peripherally acting emetic?

Syrup of ipecac is recognized as a peripherally acting emetic because it stimulates the vomiting reflex mainly through local irritation of the gastrointestinal tract. When ingested, it acts on the stomach lining and triggers nausea and vomiting in response to this irritation, making it effective for inducing emesis in certain situations, particularly in cases of poisoning.

In contrast, apomorphine is a centrally acting emetic that works by stimulating the chemoreceptor trigger zone in the brain, rather than directly affecting the gastrointestinal tract. Xylazine is primarily used as a sedative and analgesic in veterinary medicine, but it has emetic properties mainly through central action via stimulation of the alpha-2 adrenergic receptors in the central nervous system. Hydrochlorothiazide is a diuretic used to treat hypertension and fluid retention, and it does not have emetic properties. Understanding drugs based on their mechanisms of action is essential for accurate pharmacological knowledge, particularly when distinguishing between centrally and peripherally acting agents.