Ask a doctor before use if you have persistent or chronic cough as occurs with smoking, asthma or emphysema. cough that occurs with excessive phlegm (mucus). I occasional minor irritation, pain, sore mouth, and sore throat. Warnings Sore throat warning If sore throat is severe, persists more than 2 days, is accompanied or followed by fever, headache, rash, swelling, nausea, or vomiting, consult a doctor promptly. Keep out of reach of children. Stop use and ask a doctor if cough 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. sore mouth symptoms do not improve in 7 days. If pregnant or breastfeeding, ask a health professional before use.