four vent syrup is a compound medicine used in the expansion of the airways and repellent and solvent of phlegm and cough that accompany cases of flu and cold and shows its effectiveness in the treatment of chronic bronchitis and this is a result of containing a group of active substances such as bromhexine hydrochloride, gavinesin, menthol and trybutalin sulfate effective in dissolving and expelling phlegm and the appropriate doses of Forvent syrup are determined according to the pathological condition and under the supervision of the treating physician