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.

PURPOSE: Tapentadol extended release (ER) has demonstrated efficacy and safety for the management of moderate to severe, chronic pain in adults. This study evaluated the long-term safety and tolerability of tapentadol ER in patients with chronic osteoarthritis or low back pain.

METHODS: Patients were enrolled in this 1-year, open-label extension study after completing one of two 15-week, placebo-controlled studies of tapentadol ER and oxycodone controlled release (CR) for osteoarthritis knee pain (NCT00421928) or low back pain (NCT00449176), a 7-week crossover study between tapentadol immediate release and tapentadol ER for low back pain (NCT00594516), or a 1-year safety study of tapentadol ER and oxycodone CR for osteoarthritis or low back pain (NCT00361504). After titrating the drug to an optimal dose, patients received tapentadol ER (100-250 mg BID) for up to 1 year (after finishing treatment in the preceding studies); patients who were previously treated with tapentadol ER in the 1-year safety study received tapentadol ER continuously for up to 2 years in total.

FINDINGS: Of the 1,154 patients in the safety population, 82.7% were aged >65 years and 57.9% were female; 50.1% had mild baseline pain intensity. Mean (SD) pain intensity scores (11-point numerical rating scale) were 3.9 (2.38) at baseline (end of preceding study) and 3.7 (2.42) at end point, indicating that pain relief was maintained during the extension study. Improvements in measures of quality of life (eg, EuroQol-5 Dimension and the 36-item Short Form Health Survey [SF-36]) health status questionnaires) achieved during the preceding studies were maintained during the open-label extension study. Tapentadol ER was associated with a safety and tolerability profile comparable to that observed in the preceding studies. The most common treatment-emergent adverse events (incidence ≥10%; n = 1154) were headache (13.1%), nausea (11.8%), and constipation (11.1%). Similar efficacy and tolerability results were shown for patients who received up to 2 years of tapentadol ER treatment.

IMPLICATIONS: 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.).