Brolex C Syrup is used to treat used for the treatment of bronchitis, cough, and allergy. It contains Cetirizine and Ambroxol, which block the effects of a chemical messenger known as histamine, which is naturally involved in allergic reactions. Also, it thins and loosens mucus (phlegm), making it easier to cough out. In some cases, you may experience tiredness, sleepiness, dry mouth etc. Before taking this medicine, you should tell your doctor if you are allergic to any of its components or if you are pregnant/breastfeeding, and about all the medications you are taking and pre-existing medical conditions.