DR KIDS COUGH AND CHEST CONGESTION (DEXTROMETHORPHAN HBR, GUAIFENESIN) SOLUTION [CALMCO LLC] if your child is now taking a prescription monoamine oxidase inhibitor (MAOI) (certain drugs for depression, psychiatric, or emotional conditions, or Parkinson’s disease), or for two weeks after stopping the MAOI drug. If you do not know if your child’s prescription drug contains an MAOI, ask a doctor or pharmacist before giving this product a persistent or chronic cough such as occurs with asthma, or emphysema, or if cough is accompanied by excessive phlegm (mucus) a cough that persists for more than 1 week, tends to recur, or is accompanied by fever, rash, or persistent headache. A persistent cough may be a sign of a serious condition