Drug Discrimination in Methadone-Maintained Humans Study 1

Inclusion criteria

• Must be between the ages of 18-65.
• Participation in the UAMS Substance Abuse Treatment Clinic Methadone Maintenance Program or the CATAR Clinic Little Rock with maintenance on a stable dose of methadone (+ or - 10 mg) for at least 1 month prior to study entry.
• Subjects would have to be in "good standing" in the methadone maintenance program in order to participate; i.e., compliance with scheduled medication and group therapy session hours. This would be defined as < 3 missed methadone medications and missed < 3 group or <3 individual therapy sessions in the two months prior to study participation
• Subjects must submit a urine sample negative for illicit drugs prior to study entry.
• Subjects must be able to read and understand English.

Exclusion criteria

Exclusion criteria

• Ill health (major cardiovascular, renal, endocrine, hepatic disorder, to be determined by history provided by the prospective subject or laboratory evaluation as outlined below).
• Current diagnosis of other drug or alcohol physical dependence (other than tobacco).
• History of major psychiatric disorder (psychosis, schizophrenia, bipolar, depression)
• Pregnancy, plans to become pregnant or inadequate birth control.
• Present or recent use of over-the-counter psychoactive drug, prescription psychoactive drug or drug that would have major interaction with drugs to be tested.
• History of severe reaction to Narcan challenge, which may have been given as part of admission into the Methadone Maintenance Program or to reverse overdose.
• 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 with QTc interval (>420 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.