a nasal/sinus decongestant , as a stimulant , or as a wakefulness-promoting agent . The salts pseudoephedrine hydrochloride and pseudoephedrine sulfate are found in many over-the-counter preparations , either as a single ingredient or (more commonly) in combination with antihistamine s, guaifenesin , dextromethorphan , paracetamol (acetaminophen), or an NSAID (such