Breonesin

Guaifenesin, sold under the brand name Mucinex, among others,[3] is a medication used as an expectorant, intended to help cough out phlegm from the airways.[3] Chemically it is an ether of guaiacol and glycerine. It is unclear if it decreases coughing.[3] Use is not recommended in children less than 6 years old.[4] It is often used in combination with other medications.[3] It is taken by mouth.[3] ... [wikipedia]