Guaifen-C and nightmares

I started taking Guaifen 3 days ago and i had a hard time sleeping. The first day i felt that my heart was beating very fast and i could not sleep at all. The next night, again, i was not able to sleep even 30 mintues altogether, and during those 30 mintues, i had nightmares. I did not know that this medication can cause sleeplessness until i read the side affects. I knew there was something wrong becuase it is unlike me not to sleep, since i love sleeping.

I took Guaifen W/P- ephed 600 and I will NEVER again!! I barely slept at all and what little I did, I had nightmares.

I was prescribed Guaifen for nasal congestion along with Leviquin for pneumonia. I was told Guaifen might keep me up at night, so I started with just 1 tablet/day instead of 2 and took it twice a day on the weekend. Glad I did as the 1 did keep me awake as well as seem to make my mind race and gave me more dreams/nightmares than usual. On the medication, I wasn't tired but a person needs 6-8 hours of sleep every night, NOT 2 hours. Next time, I will read the side effects before I get my script filled, and call the dr or pharmacist if need be to discuss it further.

I was up all night with my heart racing and I felt like horrible. And when I did doze off I would have the worst nightmares. It made my body hurt like I had the flu and the cotton mouth is horrible. I took one pill last night before bed and it is now 12:25pm next day and still feel like I have the flu. This didn't help with my sinus congestion either I had post nasal drip all night and still now. This is a horrible medicine!!