Effectiveness and tolerability of transdermal buprenorphine patches: a multicenter, prospective, open-label study in Asian patients with moderate to severe chronic musculoskeletal pain.

BACKGROUND: We examined the effectiveness and tolerability of transdermal buprenorphine (TDB) treatment in real-world setting in Asian patients with musculoskeletal pain. METHODS: This was an open-label study conducted in Hong Kong, Korea, and the Philippines between June 2013 and April 2015. Eligible patients fulfilled the following criteria: 18 to 80 years of age; clinical diagnosis of osteoarthritis, rheumatoid arthritis, low back pain, or joint/muscle pain; chronic non-malignant pain of moderate to severe intensity (Box-Scale-11 [BS-11] pain score ≥ 4), not adequately controlled with non-opioid analgesics and requiring an opioid for adequate analgesia; and no prior history of opioid treatment. Patients started with a 5 µg/h buprenorphine patch and were titrated as necessary to a maximum of 40 µg/h over a 6-week period to achieve optimal pain control. Patients continued treatment with the titrated dose for 11 weeks. The primary efficacy endpoint was the change in BS-11 pain scores. Other endpoints included patients' sleep quality and quality of life as assessed by the 8-item Global Sleep Quality Assessment Scale (GSQA) questionnaire and the EuroQol Group 5-Dimension Self-Report Questionnaire-3 Level version (EQ-5D-3 L), respectively. Tolerability was assessed by collecting adverse events. RESULTS: A total of 114 eligible patients were included in the analysis. The mean BS-11 score at baseline was 6.2 (SD 1.6). Following initiation of TDB, there was a statistically significant improvement in BS-11 score from baseline to visit 3 (least squares [LS] mean change: -2.27 [95% CI -2.66 to -1.87]), which was maintained till the end of the study (visit 7) (LS mean change: -2.64 [95% -3.05 to -2.23]) (p < 0.0001 for both). The proportion of patients who rated sleep quality as 'good' increased from 14.0% at baseline to 26.9% at visit 6. By visit 6, the mean EQ VAS score increased by 7.7 units (SD 17.9). There were also significant improvements in patients' levels of functioning for all EQ-5D-3 L dimensions from baseline at visit 6 (p < 0.05 for all). Seventy-eight percent of patients reported TEAEs and 22.8% of patients discontinued due to TEAEs. TEAEs were generally mild to moderate in intensity (96.5%). CONCLUSIONS: TDB provides effective pain relief with an acceptable tolerability profile over the 11-week treatment period in Asian patients with chronic musculoskeletal pain. More studies are needed to examine the long-term efficacy and safety of TBD treatment in this patient population. TRIAL REGISTRATION: ClinicalTrials.gov NCT01961271 . Registered 7 October 2013 (retrospectively registered; first patient was enrolled on 28 June 2013 and last patient last visit date was 26 Apr 2015).

Inadequate treatment practices for pain relief and adverse event management in cancer patients across 10 countries/regions in Asia: a call for greater efforts to improve standards for patient care.

AIM: To examine the treatment practices for cancer pain relief and adverse event management, and the factors related to patient outcomes in the participating countries/regions. METHODS: The study was a cross-sectional survey conducted between September and December 2013 in 10 countries/regions across Asia. Adult patients with a history of cancer pain at least 1 month before study entry completed the survey questionnaire. RESULTS: A total of 1190 patients were included. The mean Box Scale-11 (BS-11) pain score was 6.0 (SD 2.1), with 86.2% experiencing moderate-to-severe pain and 53.2% receiving opioids at time of the survey. The mean BS-11 scores were 5.3 (SD 2.1) in the "others" (single non-opioid medication or untreated) group, 6.3 (SD 2.0) in the ≥2 non-opioids group and 6.7 (SD 1.9) in the opioid group. The proportions of patients experiencing moderate-to-severe pain were 79.1%, 87.3% and 93.7%, respectively. About 70% of patients reported adverse events due to their pain medications, about half had received medications to manage these symptoms. Adverse events were negatively associated with activities of daily living (P < 0.0001). Pain and hindrance to activities of daily living were negatively associated with employment status (P = 0.003 and 0.021). Unemployment was significantly associated with poorer quality of life (P < 0.0001). CONCLUSION: This analysis demonstrates inadequate management of cancer pain and treatment-related adverse events in the participating cohort. Pain and inadequate management of adverse events were negatively associated with patients' overall well-being. More collaborative efforts should be taken to optimize pain treatment and increase awareness of adverse event management in physicians.