You should talk with your healthcare provider prior to taking varenicline if you have:
- Kidney disease, such as kidney failure (renal failure)
- Any mental illness
- Heart disease
- A history of suicidal behavior
- Any allergies, including allergies to food, dyes, or preservatives.
Also, let your healthcare provider know if you are:
- Pregnant or thinking of becoming pregnant
Make sure to tell your healthcare provider about all other medicines you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
(Click Precautions and Warnings With Varenicline to learn more, including information on who should not take the drug.)
Varenicline works in a unique manner. Although the drug does not contain nicotine, it binds to nicotine receptors in the brain. This helps people quit smoking in two different ways. First, when varenicline binds to the nicotine receptor, it blocks nicotine from binding, which prevents some of the pleasurable effects of smoking. Second, it acts a little like nicotine when it binds to the receptor, which helps to decrease the effects of nicotine withdrawal.