Effectiveness of the Different Treatments in Smoking Cessation

Cochrane reviews:

Nicotine Replacement Therapy (NRT): 132 RCTs.

-Overall risk ratio (RR) and 95% confidence interval (CI) of abstinence: 1.58 (1.50 to 1.66); similar for gum, patch, inhaler, and lozenge.

-Adverse events (AEs): local irritation related to product type; no evidence of increased myocardial infarction.

Varenicline: 9 RCTs.

-The RR (95% CI) for cessation at 6 to 12 months over placebo was 2.33 (1.95 to 2.80).

-Varenicline AEs: primarily nausea, insomnia, and abnormal dreams; 10% AE drop-out rate; neuropsychiatric AEs (eg, depression, agitation, suicidal thoughts or behaviour) are infrequent butrequire monitoring.

-Reported benefit of varenicline might be influenced by industry funding and lack of a pragmatic design.

Antidepressants: 49 bupropion and 9 nortriptyline RCTs.

-The RR (95% CI) for cessation over placebo at 6 to 12 months: bupropion 1.69 (1.53 to 1.85); nortriptyline 2.03 (1.48 to 2.78).

-Bupropion AEs: primarily insomnia and dry mouth; 7% to 12% AE drop-out rate; rarely seizure (about 1/1000) and suicidal thoughts or behaviour (association unclear).

-Nortriptyline AEs: primarily dry mouth, drowsiness, light-headedness, and constipation (less at lower doses); 4% to 12% drop-out rate from AEs.

Assuming 10% placebo cessation rates (mean across studies), approximate numbers needed to treat (at 6 to 12 months) are as follows: varenicline 8, nortriptyline 10, bupropion 10, and NRT 16.

Context

Smoking cessation is the most effective preventive manoeuver for high-risk patients: an RCT of aggressive intervention for 209 patients after critical care admission achieved a 2-year quit rate of 39% (9% for placebo) and mortality of 3% (vs 12%); number needed to treat was 11.

Dosing:

-Bupropion: 150 mg is equivalent to 300 mg.

-Varenicline: 0.5 mg twice daily is as effective (or almost as effective)^,as 1 mg twice daily, but with fewer AEs.

-Nortriptyline: start with 25 mg at bedtime and increase by 25 mg every 3 to 4 days, if the desire to smoke persists, to a maximum of 75 to 100 mg; encourage a quit date 10 days in (or so) and continuefor 10 to 12 weeks.

Bottom line

Nicotine replacement, bupropion, nortriptyline (off label), and varenicline are all effective in smoking cessation; AEs vary (and might relate to quitting smoking), but they are important and require monitoring.

Note

In Malaysia, the recommended (and available) pharmacotherapy for smoking cessation are NRT (gum, lozenges, patch, inhaler) and varenicline.

Nicotine 16hour-patch and varenicline are listed in the Ministry of Health Drug Formulary as A/KK (Category of prescribers: Consultants/ Specialists/Family Physician Specialists).

Reference:

Allan,GM, Ivers N and Els C. Can Fam Physician, 57 (1), January 2011: 47.