Combination therapies are the most effective to stop smoking

The largest review to determine the effectiveness and safety of e-cigarettes and medicines.


A new study by the University of Bristol determined how varenicline, bupropion, nicotine replacement therapy (NRT), and electronic cigarettes compare with respect to their clinical effectiveness and safety.

Scientists found that combination therapies, especially varenicline and nicotine replacement therapy (NRT), are the most effective tobacco cessation pharmacotherapies. This study is the largest review to determine the effectiveness and safety of electronic cigarettes (e-cigarettes) and medicines people use to quit tobacco.

Cigarette smoking is a leading cause of premature death and illness. Three pharmacotherapies, varenicline, bupropion, and nicotine replacement therapy (NRT), are mainly recommended for smoking cessation.

Scientists identified 363 trials for effectiveness and 355 for safety. Most single and combination therapies were more effective than placebo at helping people stop smoking, with varenicline monotherapy and varenicline plus NRT combined being the most effective.

Bupropion was also effective but was associated with increased risks of having a severe adverse event. E-cigarettes showed promise, but more research is needed to establish their safety.

Dr. Kyla Thomas, Consultant Senior Lecturer in Public Health Medicine in the Bristol Medical School: Population Health Sciences (PHS) at the University of Bristol and lead author, said: “Although e-cigarettes showed promise as a means to stop smoking, more research is needed on their long-term effectiveness and safety, preferably in studies with active interventions as comparators.”

“We also recommend further research to explore the effectiveness of combination pharmacological treatment together with counseling or psychological interventions.”

Dr. Michael Dalili, Senior Research Associate in Public Health in the Bristol Medical School: PHS and co-author, added“Our study strengthens the evidence base for the use of varenicline and NRT monotherapies as first-line choices for tobacco cessation in line with current NICE recommendations. Our findings should provide reassurance to patients, clinicians, and policymakers about the safety of these treatments.”

Journal Reference:
  1. Kyla H. Thomas, Michael N. Dalili et al. Comparative clinical effectiveness and safety of tobacco cessation pharmacotherapies and electronic cigarettes: a systematic review and network meta-analysis of randomized controlled trials. DOI: 10.1111/add.15675


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