Transdermal buprenorphine in non-oncological moderate-to-severe chronic pain.

BACKGROUND: Musculoskeletal pathologies are among the most frequent causes of long-term non-oncological severe pain and consequent physical impairment. Aims of pharmacological and physical therapy are to reduce pain, promote functional recovery and improve overall quality of life. Pharmacological therapy may include the use of opioids.
OBJECTIVE: To evaluate the efficacy and tolerability of transdermal buprenorphine (TDS) in the long-term management of non-oncological, chronic, moderate-to-severe musculoskeletal pain. STUDY
DESIGN: An open-label, prospective, single-centre, 6-month study.
SETTING: A 'real world' outpatient setting. PATIENTS: Adult patients with chronic moderate-to-severe musculoskeletal pain were enrolled consecutively. INTERVENTION: Patients initially received buprenorphine TDS 11.7 microg/h (one-third of 35 microg/h patch) every 72 hours. If required, patients could be up-titrated to 17.5 microg/h (one-half of 35 microg/h patch), 23.4 microg/h (two-thirds of 35 microg/h patch) or 35 microg/h. Concomitant antiemetics were allowed. MAIN OUTCOME MEASURES: The primary endpoint was percentage mean reduction in static and dynamic pain visual analogue scale (VAS) scores at study end (10 being worst pain, 0 being no pain). Quality of life and tolerability were also assessed.
RESULTS: We enrolled 146 patients aged 41-94 years; their baseline mean +/- SD static and dynamic pain VAS scores were 6.87 +/- 1.89 and 7.70 +/- 1.74, respectively. Buprenorphine TDS initial dosages were 11.7 microg/h (n = 139), 17.5 microg/h (n = 4), 23.4 microg/h (n = 1) and 35 microg/h (n = 2). At 6 months, 89 patients were under treatment; 11% (n = 10) were receiving 11.7 microg/h, 30% (n = 27) 17.5 microg/h, 6% (n = 5) 23.4 microg/h and 53% (n = 47) 35 microg/h. Patients achieved a nonsignificant reduction in pain at rest and in movement; mean +/- SD static and dynamic pain VAS scores decreased to 1.56 +/- 2.05 and 3.54 +/- 2.02, respectively. The quality of life improved as shown by significant (p < 0.01) increases from baseline in all items relating to physical and mental health on the Short-Form 36 health survey. Patients experienced recovery of daily and social activities according to the significant (p < 0.01) increase in Karnofsky Performance Status sub-item scores. Twenty-three patients discontinued treatment because of adverse events, which were mainly gastrointestinal or CNS-related.
CONCLUSIONS: Low-dose buprenorphine TDS had good analgesic efficacy, and quality of life improved as early as 1 month after treatment initiation. Our results suggest that buprenorphine TDS is a well tolerated long-term analgesic for patients experiencing chronic musculoskeletal pain of moderate-to-severe intensity.