cough and nasal congestion
"I used this medication and had none of the insomnia or restlessness. I had the exact opposite reaction. I had been dealing with a sinus cold and was getting headaches from them. After using over the counter medication to combat the headaches I went to the doctor who prescribed Mucinex D because he said it was much more powerful. Long story short I couldn't make it through a day of work without sleeping. I at first related it to the cold, but when I halved my dosage I was still tired but not to the point of exhaustion when I took two pills. As of now my pills are gone and I don't feel tired in the least. Insomnia I can handle, falling asleep on the job I can't."