As a mucolytic agent, carbocisteine works by helping the lungs loosen phlegm easily. It is similar to ambroxol (Ambrolex, Musosolvan, Zobrixol) in action. However, if a patient has a history of asthma, doctors and pharmacies usually recommend ambroxol. Carbocisteine is a very good mucolytic though. Despite that this cough cure is used in special precaution with elderly people and asthmatic patients, doctors prescribe carbocisteine in combination with an anti-asthma agent such as salbutamol.