what are expectorant drugs
A drug may be classified by the chemical type of the active ingredient or by the way it is used to treat a particular condition. Each drug can be classified into one or more drug classes. Expectorants are drugs that increase the bronchial secretion and enhance the expulsion of mucus by air passages of the lungs. This makes it is easier to cough up the phlegm or sputum. Expectorants are used in cough mixtures for chesty coughs.