Analgesic efficacy and tolerability of transdermal buprenorphine in patients with inadequately controlled chronic pain related to cancer and other disorders: a multicenter, randomized, double-blind, placebo-controlled trial.

BACKGROUND: Buprenorphine is a potent opioid analgesic that is available in sublingual and parenteral formulations. A new formulation, buprenorphine transdermal delivery system (TDS), has been developed.

OBJECTIVE: The aim of this study was to compare the analgesic efficacy and tolerability of the 3 available dosages of buprenorphine TDS (35.0, 52.5, and 70.0 microg/h) with placebo.

METHODS: This was a randomized, double-blind, placebo-controlled, multicenter study. Patients with chronic, severe pain related to cancer or other diseases and inadequately controlled with weak opioids were randomized to receive buprenorphine TDS 35.0, 52.5, or 70.0 microg/h or placebo patch for up to 15 days. A new patch was applied every 72 hours, for a total of 5 patches. All patients were permitted rescue analgesia with sublingual buprenorphine tablets (0.2 mg) as required for breakthrough pain.

RESULTS: A total of 157 patients (86 women, 71 men; mean [SD] age, 58.7 [11.8] years) were initially enrolled in the study. Buprenorphine TDS was associated with significantly higher response rates than was placebo at the 35.0- and 52.5-microg/h dosages (36.6% and 47.5%, respectively, vs 16.2%; P=0.032 and P=0.003, respectively) and a numerically higher response rate at 70.0 microg/h (33.3%), although this difference did not reach statistical significance. Patients treated with buprenorphine TDS experienced a 56.7% reduction in use of sublingual rescue analgesic during the study compared with an 8% reduction with the placebo patch. A total of 43.5% of patients treated with buprenorphine TDS reported good or complete pain relief compared with 32.4% in the placebo group. Pain intensity decreased in a dose-dependent manner with buprenorphine TDS, and the duration of sleep uninterrupted by pain was improved by the end of the study. More than three fourths (78.8%) of patients in the placebo and buprenorphine TDS groups reported at least 1 adverse event (AE) during the study. The most common AEs were central nervous system and gastrointestinal symptoms. The majority of treatment-related AEs were mild or moderate in intensity and were typical of those occurring at the beginning of therapy with a strong opioid.

CONCLUSIONS: Buprenorphine TDS was shown to be an effective analgesic against chronic, severe pain in this study population. Patients treated with this new formulation of buprenorphine showed improved duration of sleep and reduced need for additional oral analgesics.