Patients randomized to the BUP/NX arm will receive daily doses for 13 days with sublingual administration of 2 mg buprenorphine/0.5 mg naloxone tablet(s) and/or an 8 mg buprenorphine/2.0 mg naloxone tablet(s). The starting dose on day 1 is 4 mg/1 mg BUP/NX with an additional 4 mg/1 mg, if needed, escalating in a step-wise manner to 16 mg/4 mg BUP/NX on day 3 and tapering to 2 mg/ 0.5 mg BUP/NX by days 12 to 13. Patients randomized to the clonidine arm will receive oral clonidine (0.05 to 0.1 mg depending upon weight) every 4 to 6 hours for 24 hours not to exceed 0.6 mg total on day 1. On day 2, a clonidine transdermal patch will be applied (0.1 mg/day/7-day patch with number of patches adjusted by weight). Oral clonidine will continue to be given on the second day of detoxification and increased to 0.2 mg every 6 hours or 0.1 mg every 3 hours not to exceed 0.8 mg over 24 hours. Patches will be worn all 13 days of detoxification. The dose of clonidine will be adjusted according to the proposed detoxification schedule, patient's weight, tolerance, and systolic blood pressure. Patients will receive counseling according to procedures in existence at each CTP throughout the study. Self-help detoxification handbooks will be distributed to all study participants.