FP-Cough Syrup / Uncategorized / By ervishalb FP-Cough Syrup Bronchodilator & Mucolytic Syrup Bronchodilators are medications that relax the muscles in the lungs and open the airways, making breathing easier (bronchi).Certain connections hold the mucus (sputum) in your lungs together. Mucolytics function by dissolving these linkages. When these ties are disrupted, mucus becomes less sticky and thick, making coughing easier.