EVIDENCE-BASED MEDICINE n Latest reviews from Cochrane In this section we present an abstract of a review relevant to prescribing in general practice from the latest issue of The Cochrane Database of Systematic Reviews. To view the article in full or for further information, visit www.thecochranelibrary.com Main results detected no significant excess of The authors identified 12 treatment-spe - neuropsychiatric events (RR 0.53; cific reviews. The analyses covered 267 0.17 –1.67) or of cardiac events (RR 1.26; studies, involving 101 804 participants. 0.62 –2.56). Pharmacological interventions Both NRT and bupropion were superior to Nortriptyline increased the chances for smoking cessation: an placebo (odds ratio – OR 1.84; 95% CI of quitting (RR 2.03; 1.48 –2.78). Neither overview and network meta- 1.71 –1.99, and 1.82; 1.60 –2.06 respec - nortriptyline nor bupropion were shown analysis tively). Varenicline also increased the to enhance the effect of NRT compared odds of quitting compared with placebo with NRT alone. Clonidine increased the Objectives (OR 2.88; 2.40 –3.47). chances of quitting (RR 1.63; 1.22 –2.18), Smoking is the leading preventable cause Head-to-head comparisons between but this was offset by a dose-dependent of illness and premature death worldwide. bupropion and NRT showed equal effi - rise in adverse events. Other treatments Some medications have been proven to cacy (OR 0.99; 0.86 –1.13). Varenicline failed to demonstrate a benefit compared help people to quit, with three licensed for was superior to single forms of NRT (OR with placebo. this purpose in Europe and the USA: nico - 1.57; 1.29 –1.91) and to bupropion (OR Nicotine vaccines are not yet licensed tine replacement therapy (NRT), bupro - 1.59; 1.29 –1.96). for use as an aid to smoking cessation or pion (Zyban) and varenicline (Champix). Varenicline was more effective than relapse prevention. Nicobrevin's UK Cytisine (a treatment pharmacologi - nicotine patch (OR 1.51; 1.22 –1.87), licence is now revoked, and the manufac - cally similar to varenicline) is also nicotine gum (OR 1.72; 1.38 –2.13) and turers of rimonabant, taranabant and licensed for use in Russia and some of ‘other’ NRT (inhaler, spray, tablets, dianicline are no longer supporting the the former socialist economy countries. lozenges; OR 1.42; 1.12 –1.79), but was development or testing of these treat - Other therapies, including nortriptyline, not more effective than combination NRT ments. have also been tested for effectiveness. (OR 1.06; 0.75 –1.48). This meta-analysis looked at how Combination NRT also outperformed Authors’ conclusions NRT, bupropion and varenicline compare single formulations. The four categories NRT, bupropion, varenicline and cytisine with placebo and with each other in of NRT performed similarly against each have been shown to improve the chances achieving long-term abstinence (six other, apart from ‘other’ NRT, which was of quitting. Combination NRT and vareni - months or longer); how the remaining marginally more effective than NRT gum cline are equally effective as quitting aids. treatments compare with placebo in (OR 1.21; 1.01 –1.46). Nortriptyline also improves the chances achieving long-term abstinence; and how Cytisine (a nicotine receptor partial of quitting. the risks of adverse and serious adverse agonist) returned positive findings (risk On current evidence, none of the events (SAEs) compare between the treat - ratio – RR 3.98; 2.01 –7.87), without sig - treatments appears to have an incidence ments and if there are instances where nificant adverse events or SAEs. of adverse events that would mitigate the harms may outweigh the benefits. Across the 82 included and excluded their use. bupropion trials, the meta-analysis esti - Further research is warranted into the Search and selection strategy mate of six seizures in the bupropion safety of varenicline and into cytisine's The overview covered NRT, antidepres - arms versus none in the placebo arms potential as an effective and affordable sants (bupropion and nortriptyline), nico - was lower than the expected rate treatment, but not into the efficacy and tine receptor partial agonists (varenicline (1:1000) at about 1:1500. SAE meta- safety of NRT. and cytisine), anxiolytics, selective type 1 analysis of the bupropion studies demon - cannabinoid receptor antagonists (rimon - strated no excess of neuropsychiatric (RR Citation abant), clonidine, lobeline, dianicline, 0.88; 0.31 –2.50) or cardiovascular Cahill K, et al . Pharmacological interven - mecamylamine, Nicobrevin, opioid antag - events (RR 0.77; 0.37 –1.59). tions for smoking cessation: an overview onists, nicotine vaccines and silver SAE meta-analysis of 14 varenicline and network meta-analysis. Cochrane acetate. The outcome for benefit was con - trials found no difference between the Database of Systematic Reviews 2013, tinuous or prolonged abstinence at least varenicline and placebo arms (RR 1.06; Issue 5. Art. No.: CD009329. DOI: six months from the start of treatment. 0.72 –1.55), and subgroup analyses 10.1002/14651858.CD009329.pub2. prescriber.co.uk Prescriber July/August 2013 z 21.