Varenicline
"3rd attempt on Champix..quit for 2 1/2 years the first time, then started again! The drug works great, however you need put some effort. Day 8, I've cut back from 1/2 pack per day, to 1-2 cigs daily. My advice to you..if trying to quit on Champix, when you have a craving, distract yourself with something else, you'll find it passes quickly."