smoking cessation
"Guess I'm one of those that can't take Chantix.  The first week only produced mild side effects, but on the ninth day my stool turned black which I found out due to gastro-intestinal hemorrhaging.  Before I was told to stop taking it by my doctor, I also had a balance disorder episode that lasted for several minutes.  I was lucky that I was not driving at the time.  I did find both side effects listed as possible on the Chantix brochure. "