Robitussin Plus contains the active ingredients guaifenesin and pseudoephedrine hydrochloride. Guaifenesin belongs to a group of medicines called cough expectorants and works by changing an unproductive cough to a cough that is more productive and less frequent.
Pseudoephedrine hydrochloride belongs to a group of medicines called nasal decongestants and helps clear nasal congestion (a blocked or stuffy nose).
