Patients with serious mental illness who quit smoking with a standard 12-week course of varenicline and cognitive-behavioral therapy are three times more likely to maintain that abstinence if they take a maintenance dose of the drug than if they discontinue it, according to a report published online Jan. 7 in JAMA.
In what the researchers described as the first randomized controlled clinical trial of maintenance pharmacotherapy aimed at preventing smoking relapse in people with serious mental illness, the prevalence of smoking abstinence after 1 year was 60% (24 of 40 study participants) in patients assigned to maintenance varenicline, compared with 19% (9 of 47 participants) in those assigned to placebo.
"Such maintenance treatment may reduce the high prevalence of tobacco dependence and reduce the heavy burden of smoking-related morbidity and mortality in those with serious mental illness," said Dr. A. Eden Evins of Massachusetts General Hospital and Harvard Medical School, Boston, and her associates.
The open-label study, released in advance of the 50th anniversary of the Surgeon General’s Report on Smoking and Health, involved 203 adults with schizophrenia spectrum disorder (185 patients) or bipolar disorder (18 patients) who reported smoking 10 or more cigarettes per day and whose expired carbon monoxide levels were higher than 9 ppm at baseline. All were outpatients at 10 community health centers in Massachusetts, Michigan, New Hampshire, Indiana, Alabama, or Minnesota, and all were taking stable doses of antipsychotic or mood stabilizing medication.
A total of 87 of these participants successfully completed a 12-week smoking cessation program combining up to 1.0 mg of varenicline twice daily plus weekly 1-hour group cognitive-behavioral therapy (CBT) sessions. They were randomly assigned to continue for another 40 weeks with either CBT plus 1.0 mg of varenicline twice daily (40 patients) or CBT plus matching placebo (47 patients).
The CBT, which focused on relapse-prevention skills, was tapered from weekly to monthly sessions, for a total of 15 sessions during the 40 weeks.
At 52 weeks from baseline, smoking cessation treatment was stopped, and the 59 patients remaining in the study were followed through week 64 for biochemically verified smoking abstinence and safety outcomes.
At week 52, 24 of 40 participants taking maintenance varenicline (60%) were still abstaining from smoking, compared with only 9 of the 47 patients (19%) taking placebo, for an odds ratio of 6.2. At week 64, 18 participants (45%) in the varenicline group were still abstaining from smoking, compared with only 6 (13%) in the placebo group, for an odds ratio of 5.1, Dr. Evins and her associates reported (JAMA 2014 Jan. 7 [doi: 10.1001/jama.2013.285113]).
Patients in the varenicline group also had a longer interval until smoking relapse, with a median time of 358 days, compared with those in the placebo group (35 days).
During treatment and follow-up, the two study groups showed no differences in the severity of their psychiatric symptoms, nicotine withdrawal symptoms, or self-reported overall health. No serious adverse events were attributed to the study medication.
However, because of the small sample size and the high dropout rate of the study, "it is not possible to accurately estimate the risk of serious adverse effects or to make claims regarding safety," the investigators noted.
This study was funded by the National Institute on Drug Abuse and by Pfizer. Pfizer also supplied the study medication and provided other support. Dr. Evins reported ties to EnVivo Pharmaceuticals, GlaxoSmithKline, and Pfizer, and her associates reported ties to Publicis Healthcare Communications Group, Janssen, Otsuka, AssurEx, Eli Lilly, and Pfizer.