bacterial infection
"Having had a virus for 4 weeks and then secondary Bronchitis I was just recently prescribed this.  I am only 3 days in and already there is a big difference in how I feel, the mucus is lifting, I can breathe and my chest feels less tight.  However it is not without the slightest of side effects which include nausea, a feeling which lasts about an hour after taking and a slight upset stomach and a headache but I can live with all that."