Smoking cessation medications do not appear to increase risk of neuropsychiatric side effects, study finds
The smoking cessation medications varenicline and bupropion do not appear to increase the incidence of serious neuropsychiatric side effects compared to placebo, according to a study published in The Lancet.
The study is the largest trial to date looking at the safety and efficacy of three first line smoking cessation treatments – varenicline, bupropion and nicotine patches – compared to placebo in smokers with and without psychiatric disorders, and finds than smokers who took varenicline achieved higher abstinence rates than smokers on bupropion, nicotine patches, or placebo.
The study involved more than 8000 people and was requested by the US Food and Drug Administration (FDA) following concerns about the neuropsychiatric safety of varenicline and bupropion.
“Given that an estimated 6 million people worldwide die as a result of tobacco smoking every year, we need to be able to provide maximum support for people to stop smoking. Our study shows that all three first-line smoking cessation medications are effective in helping people stop smoking, with varenicline being the most effective,” says lead author Professor Robert M. Anthenelli, University of California, San Diego, USA. 1, 2
Professor Anthenelli adds, “Clinical guidelines recommend that the most effective way to give up smoking is smoking cessation medication and counselling. However, smokers do not use these services enough, in part due to concerns that the medications may not be safe. The findings from this study, together with data from previous trials and large observational studies, make it highly unlikely that varenicline and bupropion increase the risk of moderate-to-severe neuropsychiatric side effects in smokers without psychiatric disorders.” 2
Participants were adults aged 18-75 who smoked on average more than 10 cigarettes a day and were motivated to stop smoking (82% had made at least one attempt to quit). Half (4116) had a history of a past or current stable psychiatric condition including a mood, anxiety, psychotic, or borderline personality disorder, and about half of this group were taking psychotropic medication. The other participants (4028) did not have a psychiatric condition (figures 1 & 2).
The trial was a double blind randomised trial and was designed to measure both the safety and efficacy of the two non-nicotine smoking cessation medications, varenicline and bupropion, relative to nicotine patches and placebo.
All participants were assessed to see whether they suffered any moderate-to-severe adverse neuropsychiatric events during and after treatment, including agitation, aggression, panic, anxiety, depression and suicide ideation among others. Smoking cessation was verified by measuring levels of exhaled carbon monoxide (CO) at the end of treatment (9-12 weeks), and at follow up (9-24 weeks).