While some prescribers may not actively advise against drinking alcohol whilst taking Champix, there is still a chance that the two substances can negatively interact.
Some people who have mixed alcohol and Champix have reported that their tolerance for alcohol is much lower, and they become intoxicated at a much more elevated rate. Additionally, they report that their potential for alcohol-induced blackouts increases, and they can become aggressive or rowdy more easily. At the very least, it’s wise to limit alcohol intake whilst using Champix.
That said, some studies have suggested that varenicline can help reduce alcohol intake in alcohol-dependent individuals, quelling an individual’s cravings for alcohol in a similar way to how it staves off nicotine cravings. However, there is insufficient evidence to support this hypothesis.