Open-Label Trial Comparing Oxycodone Medications

Inclusion Criteria: 1. Be at least 18 years old. 2. Be able to read and understand English. 3. Have a diagnosed chronic pain condition with pain every day or most days for the previous 6 months. 4. Be receiving the equivalent of no more than 40-120 mg daily of an opioid analgesic that can be safely converted to oxycodone; this dosage includes all use of opioid analgesics, including for "rescue" and for "breakthrough" pain. 5. Have an average daily pain rating for the baseline week of pain ratings equal to 4.0 or greater on a 0-10 numerical pain rating scale (NRS) of average pain intensity in the past 24 hours. 6. Have completed at least 6 of the 7 daily diaries during the baseline week. 7. Have at least 5 baseline week pain diary ratings equal to 3 or greater on the 0-10 NRS, with no more than one rating of 9 and no ratings of 10. 8. Have stable concomitant use of all pain-related medications for 8 weeks prior to screening and being willing to continue stable use of these medications for the duration of the trial. 9. Have the ability to either independently or with an accompanying person come to the research center for study visits. Exclusion Criteria: 1. Treatment of their chronic pain with nerve blocks or any other interventional procedure within the past 8 weeks. 2. A Beck Depression Inventory score \< 27 at baseline or clinically significant depression or dementia that, in the opinion of the investigator, may interfere with a subjects' adherence to the study protocol and/or the accurate and consistent reporting of pain. 3. History of suicide attempt within the past 2 years or current suicide plan or intent. 4. History of excessive alcohol use or any illicit drug use within the past 2 years. 5. Lack of adequate birth control in pre-menopausal women of child-bearing age and/or a positive urine pregnancy test, which will be performed on all women except those \> 2 years post-menopausal or who have had a hysterectomy). 6. History of malignancy within the past five years with the exception of successfully treated non-metastatic basal cell or squamous cell carcinomas of the skin.