Long-term Safety and Efficacy of Tapentadol Extended Release Following up to 2 Years of Treatment in Patients With Moderate to Severe, Chronic Pain: Results of an Open-label Extension Trial

Pain relief and improvements in quality of life achieved during the preceding studies were maintained throughout this extension study, during which tapentadol ER was well tolerated for the long-term treatment of chronic osteoarthritis or low back pain over up to 2 years of treatment. (ClinicalTrials.gov identifier: NCT00487435.)