Varenicline helps T2D patients quit smoking

Use of varenicline in a smoking cessation program for patients with type 2 diabetes (T2D) is safe and effective, facilitating long-term abstinence without adverse consequences, according to the results of a trial.

“Throughout the trial, patients in the varenicline group were at least three times more likely to quit smoking compared with patients in the placebo group,” the authors said.

The continuous abstinence rate (CAR) was 24 percent with varenicline vs 6.0 percent with placebo (odds ratio [OR], 4.95, 95 percent confidence interval [CI], 2.29–10.70; p<0.001).

The CARs were consistently higher with varenicline at each interval: 31.3 percent vs 7.3 percent (odds ratio [OR], 5.77; p<0.001) at weeks 9–12, 24.0 percent vs 6.0 percent (OR, 4.95; p<0.001) at weeks 9–24, and 18.7 percent vs 5.3 percent (OR, 4.07; p<0.001) at weeks 9–52. [JAMA Netw Open 2022;doi:10.1001/jamanetworkopen.2022.17709]

The same was true for the 7-day point prevalence of smoking abstinence: 40.0 percent vs 11.0 percent (OR, 7.67; p<0.001) at week 12, 29.0 percent vs 8.3 percent (OR, 4.44; p<0.001) at week 24, and 23.7 percent vs 9.5 percent (OR, 3.27; p<0.001) at week 52.

“Exhaled carbon monoxide (eCO) level–verified CAR in the varenicline group was 31.3 percent at weeks 9–12, 24.0 percent at weeks 9–24, and 18.7 percent at weeks 9–52,” the authors said.

“The ORs for the varenicline group in the present trial were higher than the ORs in previous [trials], which resulted from lower abstinence rates in the placebo group. These findings support the notion that patients with T2D who smoke have greater difficulty quitting when provided with only cessation counselling,” they noted. [Health Technol Assess 2020;24:1-46; Circulation 2010;121:221-229; Chest 2011;139:591-599]

In terms of safety, the most frequent adverse events occurring in the varenicline vs the placebo group were nausea (27.3 percent vs 11.4 percent), insomnia (19.4 percent vs 12.7 percent), abnormal dreams (12.7 percent vs 3.4 percent), anxiety (11.4 percent vs 7.3 percent), and irritability (9.4 percent vs 5.4 percent). Serious adverse events were infrequent in both groups and not related to treatment.

“There were no differences in metabolic and cardiovascular parameters between or within treatment groups. No weight gain was observed, which was somewhat surprising given that smoking cessation is typically associated with increase in body weight,” the authors said. [Addiction 2011;106:188-196; BMJ 2012;345:e4439]

They acknowledged, however, that most patients in the present trial were receiving metformin, which might have contributed to preventing weight gain after smoking cessation.

The trial included 300 T2D patients (mean age 57.4 years, 78.0 male), with 150 each in the varenicline and placebo groups.

Stubbing it out

“When investigating clinical and demographic features that influenced the CARs, we found that lifetime cumulative smoking history and stronger cigarette dependence, as assessed by Glover-Nilsson Smoking Behavioral Questionnaire (GN-SBQ), resulted in less probability of smoking abstinence over time,” the authors said.

For smokers with high cigarette dependence, quitting was especially difficult. The extent of lifetime cumulative smoking history significantly weakened the potency of varenicline. [Respir Med 2008;102:1182-1192; Lancet Diabetes Endocrinol 2015;3:423-430]

“A smoking cessation program alone was significantly less likely to be successful in patients with or affected by smoking rituals (ie, high GN-SBQ scores >23 points). This finding was not surprising given that smoking cessation medications may only alleviate nicotine withdrawal symptoms and reduce reinforcement from smoking but cannot replace the need for smoking-related rituals,” the authors explained.

In a study that evaluated the effect of adding a nicotine-free cigarette-like plastic stick to a smoking cessation program, participants who were assigned to use the plastic stick had quit rates that were more than threefold higher if their GN-SBQ scores were high, whereas those with low GN-SBQ scores obtained no benefit from using the plastic stick. [Eur Respir J 2011;38:1005-1011]

The current study “supports the use of varenicline in diabetes education programs to help patients with T2D stop smoking,” the authors said.