My wife has been on champix for about 2 months. The stopping smoking part has been great and the pills do their job exceptionally. But!! It's like being married to a different person. Her personality has completely changed. A few days ago she decided to come off the pills and within 48 hours she was vomiting.. spinning.. panic attacks. Finally she shut herself away in a room just holding her head. She immediately went back on the pills and the symptoms stopped a few hours later. Coincidence? we'll see in 4 weeks when the pills run out