Table 3.

Summary of clinical trials assessing the effectiveness of pharmacotherapies for smoking cessation on opioid-maintained patients.

References	Participants	Intervention	Assessment:Primary and Secondary Outcomes	Follow-up time point for abstinence	Results
(Hall et al., 2018)	Buprenorphine-maintained smokers	1. Skills training + NRT (patch 7 mg, 14 mg or 21 mg), (lozenges 2 mg combination or varenicline + CBT)	1. CPD and biochemical: CO + urine	3, 6, 12, and 18 months	The interventional group had higher abstinence rates than controls at 3-months FU.
(Hall et al., 2018)	N = 175	2. Information (control) 12 weeks	2. Questionnaires: FTND and others.		CPD and cannabis a month prior to FU as a predictor of smoking continuance
(Nahvi et al., 2014)	Methadone-maintained Smokers	1. Varenicline (2 mg)	1. CO abstinence at 12 weeks FU	2, 4, 8, 12, and 24 months	Varenicline higher abstinence rates at 12-weeks FU
	N = 112	2. Placebo 12 weeks	2. CO abstinence each FU, CPD, quit attempts >24 h, psychiatric or cardiac adverse events		Reduced CPD at 12 weeks
					No differences in psychiatric or adverse events between groups
(Rohsenow et al., 2017)	SUD, including OUD outpatient smokers	1. Varenicline (2 mg) or placebo	1. CO + urine cotinine	3, 6 months	Varenicline was more effective than NRT in promoting abstinence at a 3-months timepoint.
(Rohsenow et al., 2017)	N = 137	2. NRT (patch 7 mg, 14 mg or 21 mg) or placebo 12 weeks	2. CPD, or continuous abstinence assessment
(Stein et al., 2013)	Methadone-maintained Smokers	1. Varenicline (2 mg)	1. CO + salivary cotinine at 3months	6 months	Varenicline was not more effective than placebo in promoting abstinence at a 6-month time point.
(Stein et al., 2013)	N = 315	2. NRT combination (patch 21 mg or 42 mg; 4 mg gum)	2. CO at 6 months, and urine test, CPD, self-report abstinence for drugs
(Reid et al., 2008)	Methadone-maintained Smokers	1. NTR (14 mg or 21 mg) + CBT	1. CO + urine	1–9, 13, and 26 weeks	NRT + CBT promotes a small but significant reduction of CPD and abstinence during the treatment period compared to the control group.
(Reid et al., 2008)	N = 225	2. Treatment as usual 9 weeks	2.CPD
(Martin et al., 2019)	OUD vs. non-OUD outpatient smokers	1. Varenicline (2 mg) or placebo	1. CO + cotinine saliva	3, 6 months	Smoking abstinence and CPD were not significantly different between OUD vs. NOUD at 3- and 6 months time points.
(Martin et al., 2019)	N = 137 (drawn from Rohsenow, 2017)	2. NRT (patch 7 mg, 14 mg or 21 mg) or placebo 12 weeks		2. CO at 6 months, and urine test, CPD, self-report abstinence for drugs
(Cooperman et al., 2018)	Methadone-maintained Smokers	1. IMB + NRT	1. CO abstinence	3, 6 months	The interventional group reported less CPD at 3 and 6months compared to the control.
(Cooperman et al., 2018)	N = 83	2. Referral to Quitline (Control) 3 months	2. CPD, self-report quit attempts, number of days of abstinence		IMB + NRT was not more effective than placebo for abstinence at 3 or 6 months.
(Mooney et al., 2008)	Buprenorphine-maintained smokers	1. Bupropion (300 mg)	1. Combined nicotine and illicit drugs abstinence (CO and urine).	2, 4, 6, 8, and 10 weeks	Bupropion was not more effective than placebo for smoking and opioids abstinence.
(Mooney et al., 2008)	N = 40	2. Placebo 10 weeks	2. Nicotine and Opioid WD

Abbreviations: CO= carbon monoxide, CBT=cognitive behavioral therapy; CPD=cigarettes per day; FTND= Fagerstrom Test for Nicotine Dependence, FU=follow-up; IMB=model-based intervention, NRT=nicotine replacement therapy; WD=withdrawal.