Delsym 12 hour Cough Relief Medicine and Delsym Maximum Strength Adult Nighttime Cough is a combo pack which provides powerful Symptom relief. Delsym 12 hour Cough Relief Medicine provides cough relief that extends up to 12 hours to help alleviate your nagging cough. Delsym Nighttime Cough is a fast release OTC medication that quiets cough to help you sleep, relieves pain, treats runny nose and reduces fever.