Terbutaline , Acebrophylline and Guaifenesin, which relieves cough with mucus. Terbutaline is a bronchodilator. It works by relaxing the muscles in the airways and widens airways. Acebrophylline is a mucolytic which thins and loosens mucus (phlegm), making it easier to cough out. Guaifenesin is an expectorant which decreases the stickiness of mucus (phlegm) and helps in its removal from the airways. Together, they make breathing easier.