Dilanyl 1.5 mg/5 mL Syrup is used to treat the symptoms of Cough (Bronchospasm). Dilanyl Syrup works by relaxing and opening the airways. Dilanyl relax the muscles in the bronchial tubes (air passages) of the lungs. They relieve cough, wheezing, shortness of breath, and troubled breathing by increasing the flow of air through the bronchial tubes.