Which of the following is considered a common antitussive ingredient?

Dextromethorphan is recognized as a common antitussive ingredient due to its function as a cough suppressant. It works by affecting the signals in the brain that trigger the cough reflex, providing relief from coughing associated with various respiratory conditions.

In contrast, chlorpheniramine maleate is primarily an antihistamine used to alleviate allergy symptoms rather than directly suppress cough. Ibuprofen and acetaminophen are analgesics and antipyretics, focused on relieving pain and reducing fever rather than addressing cough specifically. Understanding the specific classifications and therapeutic uses of medications is crucial in pharmacology, particularly when it comes to differentiating between those that treat coughs and those that serve other purposes.