Pharmacological Interventions for Electronic Cigarette Cessation: A Systematic Review and Meta-analyses

OBJECTIVES: The rising global prevalence of electronic cigarette (e-cigarette) use poses significant public health concerns, including nicotine dependence. This systematic review and meta-analysis evaluated the efficacy and safety of pharmacological interventions for e-cigarette cessation. METHODS: We systematically searched 5 databases, including Cochrane Library, PubMed, Ovid Embase, Sinomed, and Web of Science Core Collection, up to May 1, 2024, that evaluated the efficacy and safety of pharmacological intervention compared with placebo for e-cigarette cessation. Two investigators independently screened studies, extracted data, and assessed the risk of bias. The outcomes of interest were (1) continuous abstinence rate (CAR); (2) 7-day point prevalence of e-cigarette abstinence at different weeks; and (3) adverse effects. This study was registered with PROSPERO (CRD42024577356). RESULTS: Of 1567 initially identified records, 7 studies involving 1161 participants were included. Most studies had a low risk of bias. The results indicated that varenicline (4 studies, n=463; OR=2.52, 95% CI: 1.14-5.58) was effective, while the effect of nicotine replacement therapy (NRT; 2 studies, n=538; OR=1.38, 95% CI: 0.61-3.14) was not statistically significant. One study on cytisine also suggested potential benefit. CONCLUSIONS: Varenicline has demonstrated efficacy in supporting e-cigarette cessation, whereas the current evidence for NRT and cytisine remains insufficient to draw firm conclusions. Further well-designed studies are needed to clarify the effectiveness of these 2 interventions. Although pharmacotherapies used for cigarette smoking show potential for repurposing, their utility in e-cigarette cessation should be interpreted cautiously until stronger evidence becomes available.