LAS VEGAS, NV—Fentanyl buccal tablets have been shown to provide a more rapid onset of analgesia than immediate-release (IR) oxycodone for the relief of breakthrough back pain, reported Mark Wallace, MD, of University of California San Diego, Thornton Hospital, at PAINWeek 2012.

Dr. Wallace and colleagues conducted two identically designed studies that included two randomized, open-label, dose titration periods and two randomized, double-blind, double-dummy treatment periods. Opioid-tolerant adults with a ≥3 month history of chronic back pain experiencing one to four instances of breakthrough pain per day were included. After successful titration of the agents, patients treated for 10 breakthrough pain instances with one study drug (either fentanyl buccal tablet or IR oxycodone) and for 10 breakthrough pain instances with the other. During the double-blind periods, patients rated pain intensity on an 11-point scale (ranging from 0=no pain to 10=worst pain imaginable), both prior to dosing and 5–60 minutes after receiving the dose.

The primary outcome for the study was mean pain intensity difference at 15 minutes post-dose. Secondary outcomes included: pain intensity differences at 5, 10, 30, 45, and 60 minutes post-dose; pain relief rated on a 5-point scale (ranging from 0=none; 4=complete pain relief) at 5–60 minutes post-dose; time to meaningful pain relief; and proportion of episodes with ≥33% or ≥50% reduction in pain intensity at 5–60 minutes post-dose.

A total of 331 patients were enrolled; 188 completed both periods of the double-blind treatment. At 15 minutes, the pain intensity difference per episode was significantly greater after fentanyl buccal tablet than after IR oxycodone (0.9 vs. 0.74; P<0.0001); significant differences were seen as early as 10 minutes (0.36 vs. 0.3; P=0.0015) through 45 minutes.

Pain relief was significantly greater after fentanyl buccal tablet than after IR oxycodone at 15 minutes (0.71 vs.0.59; P=0.004 ) and at 30 and 45 minutes (P<0.01). Time to meaningful pain relief occurred faster with the fentanyl buccal tablet than with IR oxycodone; significant differences were seen at ≤15 minutes (P<0.05) and ≤30 minutes (P<0.01). The proportion of episodes with ≥33% improvement in pain intensity was greater with fentanyl buccal tablet than with IR oxycodone; significantly greater reductions were seen at 30 minutes (P<0.01). The proportion of episodes with ≥50% improvement in pain intensity was also greater with fentanyl buccal tablet; significantly greater reductions were seen at 5, 10, 30, and 45 minutes (P<0.05).

“Treatment with fentanyl buccal tablet for breakthrough pain was associated with a more rapid onset of analgesia compared with immediate-release oxycodone,” said Dr. Wallace,  “with statistically significant pain intensity differences as early as 10 minutes post-treatment.”