Tobacco smoking remains a primary health concern, more significantly in developing countries and continuously exerts a huge impact on global health. Available treatments for smoking cessation are often associated with adverse side effects, thus there is a great need for new therapies for smoking cessation. N-Acetylcysteine (NAC) is a widely available and well tolerated drug that would increase the intracellular levels of glutathione which modulates oxidative, immune-inflammatory, glutamatergic and neurotrophic pathways. There is suggestive evidence for the use of NAC in smoking cessation. Despite promising preclinical and preliminary clinical findings, randomised controlled trials which aim to evaluate NAC’s efficacy for smoking cessation and substance use disorders have shown mixed outcomes. With this gap in literature this study aims to determine the effect of NAC as an adjunctive treatment for smoking cessation.

The main objective of this study was to investigate the effect of NAC as an adjunctive treatment for smoking cessation

The study covered randomised clinical trials published in peer-reviewed journals registered in the Cochrane Central Register of Controlled Trials and PubMed. Study population in the selected studies had patients 18-65 of age years and with tobacco-use disorder or patients who smoke an average of 5 sticks per day. The primary outcome would be the effect of NAC on smoking cessation. The researcher utilised Review Manager 5.4.1 for the analysis of this study.

Initial Search in PubMed and Cochrane Library identified 23 clinical trials (6 PubMed, 17 Cochrane Library). 3 articles were included in the analysis. A total of 238 participants were enrolled in the studies, with 121 enrolled in the treatment group (NAC) and 106 were in the placebo group. The mean age of participants is 36.59 years and treatment duration vary up with the shortest duration of 1 month and longest duration of 3 months. Pooled odds ratio (2.41) shows that the true population odds of smoking cessation were between 1.32 and 4.41 in favor to the participants in the NAC group with 95% confidence interval. Measurement of secondary outcomes showed a significant reduction on carbon monoxide exhaled in the NAC group compared to the placebo group (P-0.0001, MD (95CI) -2.04 (3.09,-0.99). Pooled odds ratio (3.4) shows that there is a higher odds of adverse events between 1.72 and 6.90 higher in the NAC group with 95% confidence interval.

The results of this study showed a favourable effect of NAC as an adjunctive treatment for smoking cessation. NAC has shown a great potential to address the limited access to therapy due to its good safety profile and its wide availability.