A Cochrane review included 7 studies with a total of 1 005 subjects. There was one trial each of the anxiolytics diazepam, meprobamate, metoprolol and oxprenolol and two trials of the anxiolytic buspirone. None of the trials showed strong evidence of an effect in helping smokers to quit. Confidence intervals were wide, and an effect of anxiolytics cannot be ruled out on current evidence.
Comment: The quality of evidence was downgraded by sparse data and study limitations (inadequate allocation concealment).