Composite measure to assess efficacy/gastrointestinal tolerability of tapentadol ER versus oxycodone CR for chronic pain: pooled analysis of randomized studies.

To evaluate a composite measure for chronic pain that balances pain relief with tolerability. Post hoc meta-analysis of three randomized, multicenter, double-blind studies. Subjects with moderate-to-severe chronic osteoarthritis knee pain or low back pain who had been randomized to receive active treatment with tapentadol extended release (ER; n = 978) or oxycodone controlled release (CR; n = 999). Twenty-two subjects were excluded, mainly because they did not receive treatment. We defined the composite measure as ≥30 percent pain relief without nausea/vomiting/constipation and without discontinuations (≥30 percent PRT [pain relief/tolerability]). We also considered ≥50 percent PRT as well as ≥30 percent and ≥50 percent pain relief without any adverse events of any type. To further evaluate ≥30 percent PRT, we studied its relationship with four patient-reported outcomes: EQ-5D, Physical and Mental Component Summaries of SF-36, Patient Global Impression of Change, and Patient Assessment of Constipation Symptoms. At week 12, tapentadol ER recipients were more likely to have ≥30 percent PRT than oxycodone CR recipients (OR, 3.15; 95% CI, 2.47, 4.00; p < 0.001). Significant differences were also observed with the other three composite measures (p < 0.001). At week 12, subjects with ≥30 percent PRT had more favorable changes in all patient-reported outcomes than those without and were more likely to have threshold changes in EQ-5D and SF-36 (all p < 0.001). Tapentadol ER was associated with significantly better composite outcomes than oxycodone CR. Because both pain relief and gastrointestinal tolerability appeared to be related to outcomes, the composite measure may represent a useful tool for comparing opioids that merits further evaluation.