cough and nasal congestion
"This is my second day of using Mucinex.  At this point I'm not sure why my doctor recommended it.  I never did have congestion, just a sore throat.  Anyway,  I'll not take it anymore, it's 1:00 a.m., I'm totally exhausted and cannot sleep.  Last night it was 12:30 or so, and I finally went to sleep.  I'm use to falling asleep around 9:30.  I do take sleeping pills and I just took my dose of those, hope it puts me to sleep, otherwise, how do you make it through the next day?  I just read the label, guess I missed before that it can cause sleeplessness, or I would't have taken it at all.  It's expensive and another drug going in the garbage can!"