Robitussin Children’s Cough & Chest Congestion DM Grape is a twice-the-strength, non-drowsy formula that controls and relieves frequent coughs while thinning and loosening mucus to relieve chest congestion. Suitable for children ages 6 and up, this medication comes in a grape-flavored liquid form that provides targeted relief of tough coughs and chest congestion symptoms in a kid-approved taste.