According to the authors, “The results raise questions about the current relative effectiveness of intense smoking cessation pharmacotherapies.”
The FDA first added a black box warning to varenicline in 2009 after some reports were made that the medication may increase the risk of depression and suicidal thoughts. While recent evidence suggests that the medication can be used safely, it is recommended that clinicians ask patients about a history of psychiatric illness prior to initiating varenicline treatment and monitor patients on the medication. In contrast, past studies suggest that combination nicotine replacement therapy (C-NRT) poses no greater risk than does NRT monotherapy, which has been found to be safe and well tolerated.
To compare the effectiveness of varenicline with nicotine replacement therapy, researchers from the University of Wisconsin School of Medicine and Public Health randomized 1,086 smokers (participants smoked at least 5 cigarettes per day) to one of three, 12-week open-label groups: nicotine patch only, varenicline only, and C-NRT (nicotine patch + nicotine lozenge). All participants received six counseling sessions over the course of the 12-week period, consisting of motivational, supportive, and skill-training elements.
When the participants were asked about their past-week smoking habits at 26 and 52 weeks, the data showed that there was no significant difference between the three groups as it relates to achieving abstinence, with smoking cessation rates among the groups ranging from 23% to 27% at 26 weeks and 19% to 21% at 52 weeks (abstinence was confirmed by a carbon monoxide breath test). According to the results, all medications were well tolerated but varenicline produced more frequent adverse events such as vivid dreams, insomnia, nausea, constipation, sleepiness, and indigestion.
“Earlier research suggested the superior effectiveness of varenicline and C-NRT compared with the nicotine patch; this was not evident in the current findings,” the study authors wrote. “Furthermore, varenicline and C-NRT did not differ from one another in their effects on 26- or 52-week abstinence.”
For related information, see the Psychiatric News article "Varenicline Helps in Gradual Smoking Reduction."