Ask a doctor before use if you have - cough that occurs with too much phlegm (mucus), cough that lasts or is chronic such as occurs with smoking, asthma, chronic bronchitis, or emphysema. Do not use if you are now taking a prescription monoamine oxidase inhibitor (maoi) (certain drugs for depression, psychiatric, or emotional conditions, or parkinson's disease), or for 2 weeks after stopping the maoi drug. If you do not know if your prescription drug contains an maoi, ask a doctor or pharmacist before taking this product. If pregnant or breast-feeding, ask a health professional before use. Keep out of reach of children. In case of overdose, get medical help or contact a poison control center right away (1-800-222-1222). Stop use and ask a doctor if cough lasts for more than 7 days, comes back, or is accompanied by fever, rash, or persistent headache. A persistent cough may be a sign of a serious condition.