From the Guidelines
The most important side effect to counsel patients about before starting varenicline therapy is nausea, as it is the most common adverse effect, occurring in approximately one-third of treated patients 1. When considering the potential side effects of varenicline, it is essential to prioritize those that have the most significant impact on morbidity, mortality, and quality of life.
- Nausea is a common side effect, but most cases are mild or moderate, and treatment discontinuation due to nausea is relatively rare, occurring in only about 3% of patients 1.
- Other common adverse effects reported with varenicline include headache, insomnia, and abnormal dreams 1.
- Although postmarketing reports have indicated a potential increased risk of neuropsychiatric symptoms, such as agitation, depressed mood, changes in behavior, and suicidal ideation, a more recent and higher-quality study found no statistically significant increase in these events 1.
- The 2021 study published in JAMA, which is more recent and of higher quality, found that common adverse effects reported with varenicline include nausea, insomnia, abnormal dreams, headache, and fatigue, but no significant increase in neuropsychiatric adverse events 1.
- Therefore, nausea is the most important side effect to counsel patients about before starting varenicline therapy, as it is the most common and has a significant impact on patient comfort and adherence to treatment.
From the FDA Drug Label
Nausea is the most common adverse reaction (up to 30% incidence rate). The most common side effects of varenicline tablets include: nausea
Important Side Effect to Counsel Patients On:
- Nausea is the most common side effect, occurring in up to 30% of patients, and is an important side effect to counsel patients on prior to starting varenicline therapy 2 2.
- Patients should be instructed to talk to their healthcare provider if they are having side effects such as nausea, as dose reduction may be helpful 2 2.
From the Research
Important Side Effects of Varenicline Therapy
The most important side effect to counsel patients on prior to starting varenicline therapy is:
- Nausea, which is the most common side effect of varenicline, observed in ~28% of individuals treated 3
- Nausea is also the most frequent adverse event reported in several studies, including 37.2% of participants in a randomised open-label trial 4 and 57% of users in a study examining reported symptoms among varenicline users 5
- Nausea can lead to discontinuation of treatment, with 53% of participants quitting due to side effects and other symptoms, including nausea, in a study examining the impact of symptoms experienced by varenicline users on tobacco treatment 5
- Other side effects, such as lower leg edema, weight loss, and irritation of mouth mucosa, are not as commonly reported or as significant a concern as nausea 3, 5, 6, 4
Prevalence of Nausea in Varenicline Users
Studies have consistently shown that nausea is a common side effect of varenicline therapy, with:
- 57% of users reporting nausea in a study examining reported symptoms among varenicline users 5
- 37.2% of participants experiencing nausea in a randomised open-label trial 4
- 28% of individuals treated with varenicline experiencing nausea in a genome-wide association study of nausea incidence in varenicline-treated cigarette smokers 3
- Nausea being the most frequent clinical reason for stopping varenicline and the most frequently reported suspected adverse drug reaction to varenicline in a prescription-event monitoring study 6