– Erdosteine (RV 144) is a homocysteine-derived thiol derivative with mucolytic and free radical scavenging properties. Erdosteine and its metabolites modulate mucus production and viscosity, by which facilitating mucociliary transport and improving expectoration. This agent also suppresses the chemical-induced cough reflex as well as protects lung tissues from damages caused by cigarette smoking mediated through free radicals scavenging.