Background Managed withdrawal is a necessary step prior to drug-free treatment or as the endpoint of substitution treatment. Objectives To assess the effects of buprenorphine versus tapered doses of methadone, alpha 2-adrenergic agonists, symptomatic medications or placebo, or different buprenorphine regimens for managing opioid withdrawal, in terms of the intensity of the withdrawal syndrome experienced, duration and completion of treatment, and adverse effects.