Which medicine is sometimes administered to induce vomiting?

Ipecac syrup is traditionally used to induce vomiting in cases of certain types of poisoning or overdose. This substance works by irritating the stomach lining and stimulating the brain to initiate the vomiting reflex. It is specifically designed for this purpose and has been a common treatment option in emergency situations, particularly in children who may ingest harmful substances.

Although activated charcoal is used in poisoning cases to absorb toxins in the gastrointestinal tract, it does not induce vomiting and is therefore not considered a method to expel stomach contents. Hydrochloric acid is a corrosive substance and is not used therapeutically to induce vomiting; rather, it is a component of gastric acid in the stomach. Apomorphine is a medication that can induce vomiting as well, but it is not as commonly used or accessible in the same way as ipecac syrup. Given this context, ipecac syrup stands out as the correct choice among the options provided.