It is unclear whether increasing the dose of varenicline beyond the standard dose of 2 mg/d would improve smoking abstinence.
We examined the effect of 3 mg/d of varenicline on smoking abstinence among smokers who had reduced their smoking by 50% or more in response to 2 mg/d for at least 6 weeks but had not quit smoking. Of 2833 patients treated with varenicline, dosage of a subset of 73 smokers was increased to 3 mg/d after 6 weeks. We used a propensity score analysis involving multiple baseline covariates to create a comparative sample of 356 smokers who remained on 2 mg/d. All smokers received concurrent and similar smoking-cessation counseling.
At 3 months, we found higher 7-day point prevalence smoking-abstinence rate in the 3-mg group (26%) than in the 2-mg group (11.5%, χ2 = 10.60, P < 0.001; risk ratio [RR], 2.3; 95% confidence interval [CI], 1.4–3.6). The difference in abstinence rates remained significant at the 6-month (P < 0.001; RR, 2.6; 95% CI, 1.6–3.9) and 9-month follow-up (P < 0.001; RR, 2.2; 95% CI, 1.4–3.3).
A relatively small increase in the daily dose of varenicline seems to offer a benefit for those who are not able to achieve total abstinence after approximately 6 weeks of 2 mg/d.
From the *Department of Behavioral Science, The University of Texas MD Anderson Cancer Center, Houston, TX; †Department of Psychiatry, Central Michigan University, Mt Pleasant, MI; and ‡Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX.
Received May 21, 2017; accepted after revision October 29, 2017.
Reprints: Maher Karam-Hage, MD, Department of Behavioral Science, The University of Texas MD Anderson Cancer Center, Unit 1330, Houston, TX 77030 (e-mail: email@example.com).
Work on this article was supported by MD Anderson's Cancer Center support grant (CA016672), funded by the National Cancer Institute. The State of Texas Tobacco Settlement funds were provided to our program by MD Anderson.