Combined nicotine replacement therapy may boost smoking cessation rates

Combining a nicotine patch plus a nicotine e-cigarette could potentially boost the likelihood of smoking cessation in adults aiming to quit smoking, according to a study from New Zealand.

“[W]hen looking at continuous abstinence from smoking, provision of patches plus a nicotine e-cigarette resulted in three to seven more smokers per 100 quitting long-term … than with patches plus a nicotine-free e-cigarette,” said the researchers.

Adult smokers who aimed to quit smoking within the following 2 weeks and with no history of e-cigarette use were randomized to receive 24-hour nicotine patches only (21 mg at one patch/day; n=125), nicotine patches plus nicotine e-cigarettes (18 mg/mL; n=500), or nicotine patches plus nicotine-free e-cigarettes (n=499) for 14 weeks. Telephone-based behavioural support was provided on a once-weekly basis for 6 weeks (median uptake, three sessions). E-cigarette use during the trial was as and when needed.

Six months after the agreed-upon quit date, a greater proportion of smokers who used both nicotine patches and nicotine e-cigarettes demonstrated continuous abstinence from smoking – determined through carbon monoxide exhalation (≤9 ppm) – than those who used patches plus nicotine-free e-cigarettes (7 percent vs 4 percent; relative risk [RR], 1.75; p=0.038; risk difference [RD], 2.99, 95 percent confidence interval [CI], 0.17–5.81). [Lancet Respir Med 2019;doi:10.1016/S2213-2600(19)30269-3]

Smokers who used nicotine patches plus nicotine e-cigarettes had numerically but not significantly better continuous abstinence rates at 6 months than those who only used patches (2 percent; RR, 2.92; p=0.05; RD, 4.60, 95 percent CI, 1.11–8.09), with the small sample size likely to blame for the lack of significance.

Self-reported quit rates at 1, 3, and 6 months favoured the patches plus nicotine e-cigarette group over the patches plus nicotine-free e-cigarette group (RR, 1.28; p=0.005, RR, 1.69; p<0.001, and RR, 1.68; p=0.001, respectively) or the patches-only group (RR, 2.25; p<0.001, RR, 2.25; p<0.001, and RR, 2.23; p=0.007, respectively).

The rate of study withdrawal or loss to follow up was higher in the patches-only group compared with the patches plus nicotine e-cigarette and patches plus nicotine-free e-cigarette groups (50, 32, and 33 percent, respectively).

“[It appears that] a treatment regimen that includes e-cigarettes is much more acceptable than patches alone … Treatment acceptability is crucial to widespread adoption of treatment,” said Professor Neal Benowitz from the University of California San Francisco in San Francisco, California, US, in a commentary. [Lancet Respir Med 2019;doi:10.1016/S2213-2600(19)30308-X]

Eighteen serious adverse events (AEs) occurred in the patches plus nicotine e-cigarette group (two of which were life-threatening heart attacks in one participant), 27 in the patches plus nicotine-free e-cigarette group (with one life-threatening heart attack), and four in the patches-only group. The one death in the patches plus nicotine-free e-cigarette group was due to accidental drug overdose. None of the serious AEs were considered treatment-related and serious AE incidence did not significantly differ between groups.

Given the strict tobacco control measures such as restricted advertising and low e-cigarette use in New Zealand, the findings could potentially apply “to countries with similar policy backgrounds,” said the researchers.

While individuals using both tobacco and e-cigarettes should be advised to completely switch to e-cigarettes, the lack of long-term safety data on these devices warrants cessation of use altogether, they added.  

At present, the combination of short- and long-acting nicotine replacement therapy is the “preferred first-line approach” for smoking cessation, said Benowitz. Future research should look into the comparative efficacy between dual nicotine replacement therapy with e-cigarettes over e-cigarettes alone, he suggested.