It can lead to constipation, drowsiness, certain gastrointestinal disturbances, nausea, vomiting, and in very high doses, may even lead to respiratory depression, says Dr Khanna. It is used in most of the cough syrups available over the counter and one has to ensure that whenever buying a cough syrup, always you should get it done and written by a healthcare professional, a pediatrician, or an MD medicine person so that you give it in an appropriate dose only if it is required, he suggests.
