Guaifenesin / pseudoephedrine
cough and nasal congestion
"I had sinus congestion and consequently serious pain under my eyes in the sinus area accompanied by confusion and inability to think clearly. After one Mucinex D tablet, the pain was gone. I suffered from mild insomnia that night, but I'd rather have the insomnia than the pain. I also had less ear pressure/pain during descent in an airplane after taking this drug. Another benefit for me. Thanks Mucinex."