Multiple effectiveness aspects of tapentadol for moderate-severe cancer-pain treatment: an observational prospective study.

Background: Previous studies have shown the efficacy of tapentadol (TP) for chronic cancer pain. We evaluated multiple effectiveness aspects of TP prolonged release on moderate severe cancer-related pain, neuropathic pain (NeP), patient satisfaction, and quality of life. Methods: An observational prospective study was conducted on 80 cancer patients. Opioid-naive patients received a starting dose of prolonged-release TP 50 mg twice daily, and opioid-experienced patients were switched to TP, not to exceed 500 mg/day. Treatment response was evaluated at 3, 6, 30-40, and 60-70 days through response rate, numeric rating-scale scoring, survival analysis (time to event for response), pain-intensity difference, TP escalation-index percentage, and effects on NeP. The drug-sparing effect on concomitant therapies was evaluated. Results: Seventy of 80 patients (88%) were responders to treatment (95% CI 78%-94%). Compared to T-0, pain-intensity reductions were statistically significant for all intervals (P<0.01), with better results at T-3/T-4. NeP was significantly reduced at T-4 (P<0.01). The probability of response was low at the initial stages and increased during the study. Pain-intensity differences decreased during the study, though without significance. Two patients (2.5%) left the study for TP-induced side effects. A significant improvement in quality of life was observed after 30-40 days (P <0.01). The majority of patients were "satisfied", "very satisfied", or "extremely satisfied" (T-3-T-4). Conclusion: TP was effective in terms of drug-sparing effect, response rate, TP escalation-index percentage, and NeP management. By comparing data from the survival analysis with the response rate and time to response (numeric rating scale from T-0 to T-4), we found that although TP induced a quick response, a longer period of therapy and higher doses were needed to improve the positive result.