Varenicline for opioid withdrawal in patients with chronic pain: A randomized, single-blinded, placebo controlled pilot trial

Background and objectives: The objectives of this randomized, single-blinded, placebo-controlled pilot trial were to investigate the effects of varenicline on opioid withdrawal among chronic pain patients undergoing opioid detoxification in an interdisciplinary pain program and the feasibility of varenicline use in this population. Methods: Twenty-one patients were recruited (varenicline. =. 10, placebo. =. 11), and 7 patients in the varenicline and 11 in the placebo group completed the study. Opioid withdrawal was quantified using the Clinical Opiate Withdrawal Scale, and varenicline-related adverse effects were assessed. Results: Opioid withdrawal scores tended to decrease over the course of opioid tapering in those receiving varenicline and increase in those receiving placebo. Varenicline was well-tolerated in this population, with no adverse drug effects (including nausea) observed and no effect on improvements in pain severity and depression. Conclusions: This randomized pilot study provides preliminary data for future trials of varenicline in opioid-dependent adults with chronic pain undergoing medically directed opioid detoxification.