An Open-label Evaluation of Tapentadol Extended Release (ER) in Participants With Moderate to Severe Chronic Pain After Conversion From Hydrocodone, Oxycodone Controlled Release (CR), and/or Morphine Sustained Release (SR)

Inclusion Criteria: * Have a clinical diagnosis of knee or hip osteoarthritis (OA) with history of pain at the reference joint or clinical diagnosis of low back pain (LBP) of non malignant origin for at least 3 months before the screening visit; Be taking hydrocodone, oxycodone CR, or morphine SR for the treatment of chronic LBP, or OA of the knee or hip for at least 2 weeks before the screening visit; Have a baseline pain intensity score of ≥4 on an 11-point pain intensity numeric rating scale; Be willing and able to independently communicate pain characteristics, complete all protocol required measurements/assessments without assistance, understand and complete self-administered questionnaires and adhere to the prohibitions and restrictions specified in this protocol. Exclusion Criteria: * Had surgery in the low back area or the reference joint within 3 months before the screening visit, or will not have fully recovered from surgery by the screening visit, or is expected to require surgical intervention in the low back area or the reference joint during participation in the study; For participants with OA of the hip or knee, has a clinical history and findings at the reference joint suggesting the pain is secondary to crystal-induced, metabolic, infectious, and/or autoimmune disease(s); Has a known history of severe chronic renal insufficiency, severely impaired hepatic function, or alanine aminotransferase or aspartate aminotransferase greater than three times the upper limit of normal; Has a history of seizure disorder, epilepsy, or recurrent seizures; Has any of the following within 1 year before the screening visit: mild/moderate traumatic brain injury, stroke, transient ischemic attack, or brain neoplasm; Has a known or suspected history of alcohol abuse in the past 10 years or any history of drug abuse; Has a history of malignancy within 2 years before the screening visit, with the exception of basal cell carcinoma that has been successfully treated; Has significant respiratory depression, acute or severe bronchial asthma, or hypercapnia and paralytic ileus; Has a known history of allergies, hypersensitivity, or contraindication to tapentadol, hydrocodone, morphine, oxycodone, or acetaminophen or their excipients; In a participant taking oxycodone CR or morphine SR at screening, is also taking more than 2 doses per day of an IR opioid for breakthrough pain (exclusion does not apply if prior opioid is hydrocodone); Is taking daily acetaminophen at a dose that exceeds 3,000 mg/day, including both acetaminophen and acetaminophen-containing combination products; Has received systemic corticosteroids within 4 weeks before the screening visit; For participant with OA, has received an injection of hyaluronic acid into the reference joint within 4 weeks before the screening visit; Has taken a monoamine oxidase inhibitor within 14 days before the screening visit; Has received an investigational drug or used an invasive investigational medical device within 30 days before the screening visit or is currently enrolled in an investigational study; Has previously participated in this clinical study; Is a woman who is pregnant, breast-feeding, or planning to become pregnant within 2 weeks after the last dose of study drug; Has any planned procedure that would require supplemental analgesics during the time of expected participation in the study; Has any significant pain condition other than chronic LBP or OA that, in the opinion of the investigator, could confound the assessment or self-evaluation of pain; Current diagnosis of fibromyalgia, complex regional pain syndrome, acute spinal cord compression, bowel or bladder dysfunction as a result of cauda equina compression, back pain caused by secondary infection, or pain caused by suspected neoplasm; Have answered "yes" to items 1 and 2 in the Columbia Suicide Severity Rating Scale administered at the screening visit.