Chantix
"I have been taking Chantix for nearly 3 weeks.  I have almost all of the symptoms mentioned by other users and was really surprised to hear people talk about lower back pain, which I have as well and did not realize it could be from the medicine.  While the nausea is subsiding, I too, am angry and agitated most of the time. I also am experiencing episodes of severe depression. I suffered a major heart attack last October and was a two pack a day smoker.  I was having success using an E cigarette but when I had problems with them, I returned to smoking.  I am still smoking after with the Chantix but hope I will be able to stop soon."