The purpose of this study is to examine the abuse liability of oxycodone and codeine in individuals with, and without, a history of prescription opioid abuse. The subjective and reinforcing effects of each drug will also be examined in the presence, and absence, of experimentally induced pain.

Prescription opioid abuse is becoming an increasingly widespread and serious public health concern. The 2001 National Household Survey on Drug Abuse report revealed that the number of first-time users of prescription opioid medications for non-medical reasons reached 2 million in the year 2000, a number that has quintupled since 1984. Despite this trend, little experimental research has been directed towards understanding who may be abusing these medications, and under what conditions. The grant will examine the reinforcing, subjective, performance, and physiological effects of two commonly prescribed opioid medications (oxycodone and codeine) in two separate studies. Because it is not clear who is abusing prescription opioids, the medication effects will be compared in drug abusers and non-drug abusers. Additionally, because it is not clear under what conditions these medications are used, the effects of oxycodone and codeine will be examined in the presence and absence of experimentally induced pain. The results of these studies will yield important information about who may be abusing prescription opioid medication, and will provide a better understanding of several important variables that may influence the propensity to abuse these medications.

The following two studies will be performed during the grant period: 1) a study to examine the abuse liability of oxycodone; and 2) a study to examine the abuse liability of codeine. Both studies will include two groups of participants: prescription opioid abusers and non-abusers.

• Opioid-Related Disorders
• Substance-Related Disorders

Inclusion Criteria:

• In good physical health
• Women reporting regular menstrual cycles lasting between 24 to 35 days
• Able to perform study procedures
• Normal body weight
• Use of opioids for medical purposes (cough, pain, or diarrhea) or recreational purposes at least twice in lifetime with no serious adverse effects
• Current opioid abuse, but not opioid dependence (drug abusers only)

Exclusion Criteria:

• On parole or probation
• Recently convicted of a crime of violence
• History of significant violent behavior
• Current Axis I psychopathology
• Significant Axis II disorder
• Pregnancy
• Women who have irregular menstrual cycles, or who are dysmenorrheic, amenorrheic, or menopausal
• Women who have been pregnant or breastfeeding within the past 6 months
• Women who have had a miscarriage or abortion within the past 6 months
• Women who meet DSM-IV criteria for premenstrual dysphoric disorder
• Women who report suffering from moderate to severe premenstrual symptoms
• Women seeking treatment for premenstrual problems
• Taking prescription or over-the-counter psychotropic medication
• History of chronic pain, or routinely uses over-the-counter analgesics (more than 4 days per month)
• Blood pressure greater than 150/90 mm Hg
• Reports of sensitivity, allergy, or contraindication to opioids

• Non-drug abusers:

  1. Current or lifetime history of substance abuse or dependence according to DSM-IV criteria (those requiring detoxification)
  2. Consumes more than 500 mg caffeine daily
  3. Seeking treatment for substance use