Chantix Drug Interactions
It is unlikely for Chantix™ (varenicline tartrate) to interact with most other medicines. Chantix has been studied in combination with many other medications without causing any problems.
Cimetidine (Tagamet™) can increase the level of Chantix in your blood, possibly increasing your risk of Chantix side effects. However, this interaction usually does not cause any problems for most people. If you notice an increase in side effects when taking cimetidine, you may want to discuss this with your healthcare provider (who may suggest using one of the many cimetidine alternatives available.)
It is possible that not all drug interactions with Chantix are known at this time. Therefore, you should talk with your pharmacist or healthcare provider about any specific drug interactions that may apply to you.