what is robitussin ac
Codeine is in a group of drugs called narcotics. It is a cough suppressant that affects the signals in the brain that trigger cough reflex. Guaifenesin is an expectorant. It helps loosen congestion in your chest and throat, making it easier to cough out through your mouth.The combination of codeine and guaifenesin is used to treat cough and to reduce chest congestion caused by upper respiratory infections or the common cold.Codeine and guaifenesin will not treat a cough that is caused by smoking, asthma, or emphysema.t helps loosen congestion in your chest and throat, making it easier to cough out through your mouth. The combination of codeine and guaifenesin is used to treat cough and to reduce chest congestion caused by upper respiratory infections or the common cold.