We will be comparing Varenicline to placebo in a single-blinded placebo controlled, randomized study

We will be using a placebo in a randomized, controlled, single-blinded trial to look at varenicline for the indication of facilitating opioid tapering in opioid-dependent patients with chronic pain.

Patients will be randomly assigned to receive either varenicline or placebo for 45 days. Patients assigned to varenicline and are current smokers will receive 0.5mg by the oral route once a day for 3 days, followed by 0.5mg twice a day for 4 days. After the first week the dose will be increased to 1mg twice daily for the remainder of the active treatment period of the study. Patients assigned to varenicline and are non-smokers will receive 0.5mg by the oral route once a day for 6 days, followed by 0.5mg twice a day for 6 days. After the first 12 days the dose will be increased to 1mg twice daily for the remainder of the active treatment period of the study. Patients assigned to placebo will receive identical looking capsules in a dosage schedule similar to varenicline.

During their treatment, patients are closely monitored by a multidisciplinary team, and there are regular assessments of pain, depression, substance use, and pain-related physical and emotional functioning

During their treatment, patients are closely monitored by a multidisciplinary team, and there are regular assessments of pain, depression, substance use, and pain-related physical and emotional functioning