Safety Study of Oxycodone Hydrochloride and Naltrexone Hydrochloride Extended-Release Capsules in Subjects With Moderate to Severe Chronic Noncancer Pain

Inclusion Criteria: * Subject has moderate to severe chronic noncancer pain (duration of at least 3 months) requiring a continuous around-the-clock opioid analgesic for an extended period of time. Conditions may include, but are not limited to, osteoarthritis, chronic low back pain, or other opioid -responsive pain conditions. * Subject agrees to refrain from taking opioid medications other than study drug during the study. (The exception is during the Pre-Treatment Period when the subject may continue current opioid therapy to guide first 4 weeks of the Treatment Period when the subject may administer immediate-release oxycodone to support conversion to study drug.) Exclusion Criteria: * Subject has moderate or severe chronic pain due to cancer, migraine, recent trauma, infection, or other pain expected to be short-term (duration less than 3 months). * Subject has a documented history of alcohol or drug abuse within 1 year prior to study entry that in the Investigator's judgment would impact subject participation. * Subject has ongoing or active alcohol or drug abuse that in the Investigator's judgment would impact subject participation. * Subject has a positive urine drug test for illicit drug use or medications at screening without legitimate medical explanation. * Subject has a clinically significant medical condition (e.g., cardiovascular, neurological, renal, hepatic, pulmonary, gastrointestinal, endocrine, hematological, immunological, rheumatological, metabolic, or psychiatric) or physical examination, vital signs (VS), 12-lead electrocardiogram (ECG), clinical laboratory abnormalities that in the opinion of the Investigator would impact the safety of the subject during study participation. * If female, the subject is pregnant or breast-feeding. * Subject has a known history or known hypersensitivity to oxycodone, oxycodone salts, naltrexone or acetaminophen,or pharmacological similar compounds. * Subject is historically non-responsive to oxycodone treatment or requires greater than 160 mg oxycodone in a 24-hour time interval.