Effects of Gabapentin Versus Placebo on Buprenorphine Detoxification of Opioid-dependent Individuals

Inclusion Criteria: * Availability to attend clinic 6 days a week for approximately 30-60 minutes. * Participants must fulfill DSM-IV criteria for opioid dependence. These criteria will be ascertained in the following manner: the physician will determine whether the individual is appropriate based on several clinical assessments that are routinely employed by methadone program physicians, including history and severity of opioid use, presence of track marks, prior treatment history, self-reported and/or observed signs and symptoms of opioid withdrawal. If any individual's degree of opioid dependence is questionable, that person will be excluded from further consideration as a participant. * Participants must submit a urine negative for drugs of abuse other than opioids prior to starting the study. Exclusion Criteria: * Unstable medical condition or stable medical condition that would interact with study medications or participation. * History of major psychiatric disorder (psychosis, schizophrenia, bipolar, depression) * Pregnancy or plans to become pregnant or inadequate birth control (adequate birth control includes abstinence, condoms, birth control pills, etc). * Present or recent use of over-the-counter psychoactive drug, prescription psychoactive drug or drug (including Maalox) that would have major interaction with drugs to be tested. * Liver function tests greater than 3 times normal, BUN and Creatinine outside normal range, or thyroid function tests outside normal range. * EKG abnormalities including but not limited to: bradycardia (\<60 bpm); prolonged QTc interval (\>450 msec); Wolff-Parkinson White syndrome; wide complex tachycardia; 2nd degree, Mobitz type II heart block; 3rd degree heart block; left or right bundle branch block. * Physical dependence on alcohol or drugs other than opioids or tobacco (as determined by physician assessment).