Smoking in Cancer Care (PDQ®): Supportive care - Health Professional Information [NCI] - Pharmacological Treatment
Table 4. Nicotine Patches continued...
A boxed warning for varenicline addresses the risk of neuropsychiatric events—specifically, suicidal ideation or behavior, agitation or hostility, depressed mood, and uncharacteristic behavior or thinking. For patients with significant comorbidities, the risks of smoking and varenicline use must be weighed against the benefits of smoking cessation. The dose-finding trial and package insert provide evidence that the incidence of adverse events is somewhat dose dependent.[10,15] It is not known, however, whether cardiovascular risks—in particular, in patients with cardiac comorbidities—are dose related because the study evaluating varenicline in patients with stable cardiovascular disease only studied varenicline 1 mg twice a day. This is an area in need of investigation.
In a pooled analysis of two randomized studies (total N = 2,052) in which varenicline was directly tested against bupropion SR and a placebo, results showed continuous abstinence rates of 44% with varenicline, 29.7% with bupropion SR, and 17.7% with placebo at weeks 9 through 12. Abstinence rates were followed through week 52 at study end, with varenicline at 22.4%, bupropion SR at 15.4%, and placebo at 9.3%. Factors found in previous studies to predict better quit rates—such as being older, being male, having a lower level of nicotine dependence, smoking fewer baseline cigarettes, and having the first cigarette of the day at a later time—were not found to be predictive of higher quit rates in this pooled analysis.
In June 2011, the FDA updated the prescribing information label for varenicline to warn that the drug may increase the risk of cardiovascular adverse events in patients who have cardiovascular disease. The change is based on findings from a clinical trial of 700 smokers who had cardiovascular disease.
Table 5. Varenicline
|bid = twice a day; Rx = prescription.|
|Rx||Chantix||0.5 mg/d, days 1–3; 0.5 mg bid, days 4–7; then 1.0 mg bid through week 12||Nausea, insomnia||Risk of toxicity higher in patients with impaired renal function.|
|Not tested in children and pregnant women.|
Bupropion Hydrochloride (HCl)
Also used as an antidepressant, bupropion HCl (Zyban) is a non-nicotine aid to smoking cessation. It is a relatively weak inhibitor of the neuronal uptake of norepinephrine, serotonin, and dopamine and does not inhibit monoamine oxidase. The exact mechanism by which bupropion HCl enhances the ability of patients to abstain from smoking is unknown; however, it is presumed that this action is mediated by noradrenergic or dopaminergic mechanisms. One study [Level of evidence: I] failed to find any additional value of bupropion HCl in reducing relapse in individuals using the nicotine patch compared with a placebo either as part of a relapse prevention program (after the end of successful patch therapy) or as a second-level treatment for individuals who were still smoking after nicotine-patch therapy.