Robitussin chesty coughs gives you a fast acting cough syrup that can be used to treat symptoms of a dry cough or sore throat it is non drowsy how it works robitussin cough syrup is a soothing formula that gives you all in one relief for a stubborn cold or chesty cough it is specially designed to reduce congestion and is a full strength medicine that breaks down phlegm and clears any nasal blockages