Effects of Pioglitazone, a PPARgamma Receptor Agonist, on the Abuse Liability of Oxycodone

This 9-week investigation will use an inpatient/outpatient design in which participants will be maintained on ascending doses of pioglitazone (3 weeks on placebo followed by 3 weeks on PIO 15 mg followed by 3 weeks on PIO 45 mg). At the end of each maintenance period the effects of oxycodone (0, 10, and 20 mg) will be examined during a single laboratory session using a cumulative dosing procedure.

Inclusion criteria

• Recreational use of prescription opioids at least once per month within the past year
• No current major mood, psychotic, or anxiety disorder
• Physically healthy
• aspartate aminotransferase (AST) or alanine aminotransferase (ALT) within normal limits
• Able to perform study procedures 6.21-45 years of age

7.Blood glucose concentration between 70-145 mg/dl for men and 70-125 mg/dl for women (fasting) 8.Hb > 13 for men and Hb > 11 for women with no other evidence of medical disorder resulting in blood loss or anemia/hematological disease

Exclusion criteria

• Physical dependence on any drugs, excluding nicotine and caffeine
• Participants requesting treatment
• Participants on parole or probation
• Pregnancy or lactation: Female participants must agree to the use of a barrier control method of contraception (e.g. male and female condoms, diaphragms, cervical caps and contraceptive sponges used in combination with spermicide)
• Current or recent history of significant violent behavior (within the past 6 months)
• Current major Axis I psychopathology that might interfere with ability to participate in the study
• Significant suicide risk
• Current chronic pain
• Current or history of congestive heart failure, edema, or diabetes mellitus
• Sensitivity, allergy, or contraindication to opioids or pioglitazone
• Unstable physical disorders that might make participation hazardous, such as end-stage AIDS, hypertension (blood pressure > 140/90), or heart disease (please note that participants will be asked about previous visits to a cardiologist, chest pain, or strong palpitations; if these exist, they will be referred to a cardiologist and excluded unless cleared for participation by a cardiologist)