Varenicline has been reported as an effective treatment for smoking cessation, however there have been some concerns regarding its safety in terms of depression and suicide. A review of available data has concluded that there is no evidence for increased risk of depression or suicidal behaviour amongst varenicline users.
Varenicline is a drug that mimics nicotine in the body, interfering with nicotine receptors in the brain. By doing this it can decrease both the urge to smoke, and reduce withdrawal symptoms for people who are trying to quit smoking.
There have been conflicting results regarding the effect of varenicline on risk of depression and suicide. A study published this month in the British Medical Journal has reviewed the available literature, conducting a meta-analysis, comparing the results of the currently available data. Studies were included if they used the recommended dose of 1mg varenicline, twice a day, and reported on depression, suicidal ideation, suicide attempt, suicide, insomnia, sleep disorders, abnormal dreams, somnolence, fatigue, anxiety, and death. A total of 39 studies were analyzed, including 10 761 participants (5 817 were prescribed varenicline 1 mg twice daily, and 4 944 were prescribed placebo).
The study reported no increase in risk of irritability, aggression, or somnolence. They did, however, report an increased risk of sleeping disorders, insomnia, abnormal dreams, and fatigue. The study did not find an increase in the risk of suicide or attempted suicide, suicidal ideation, depression, or death when compared with participants in the placebo group. There were no differences reported for depression and suicidal tendencies between ages, gender, ethnicity, smoking status, or pre-existing psychiatric illness.
The study also reported a reduction in anxiety in those taking varenicline, which the authors suggest may be an outcome of quitting smoking, which has been shown to reduce anxiety. Those taking varenicline were three times more likely to quit smoking compared to participants in the placebo group. The authors conclude that varenicline does not increase the risk of depression or suicidal behaviour, and that this should provide some reassurance to the use of varenicline as a quitting aid. They suggest that the health benefits of quitting smoking outweigh the risks of varenicline.
Thomas, KH, Martin, RM, Knipe, DW, Higgins, JPT, Gunnell, D. “Risk of neuropsychiatric adverse events associated with varenicline: systematic review and meta-analysis.” BMJ 2015;350:h1109
Varenicline Fact Sheet Available from: http://www.quitnow.ca/tools-and-resources/quitting-medications/varenicline-champix.php Last Accessed March 18, 2015.
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Written by Deborah Tallarigo, PhD