Background: Current clinical guidelines have identified the need for studies comparing the effect of different short-acting or rapid-onset opioids for the treatment of breakthrough pain (BTP). In this study we evaluated the efficacy and safety of treatment with fentanyl buccal tablet (FBT) in comparison with immediate-release oxycodone in alleviating BTP in opioid-tolerant patients with chronic pain.
Methods: In this cross-over design study, opioid-tolerant patients were randomized to open-label titration with FBT (200, 400, 600, 800 μg) followed by oxycodone (15, 30, 45, 60 mg) or vice versa for the management of BTP. After titration to a successful dose of both study drugs, patients were rerandomized to double-blind treatment for 10 BTP episodes with 1 of the already identified successful doses of study drug followed by cross-over to double-blind treatment for 10 BTP episodes with the other study drug. The primary efficacy measure was the difference in pain intensity (based on an 11-point numerical scale) 15 minutes after administration of study drug (PID(15)). Other efficacy measures included PID at other time points postdose (5 through 60 minutes), the sum of pain intensity differences (SPID) at 30 and 60 minutes postdose, pain relief (5 through 60 minutes), proportion of BTP episodes for which patients experienced meaningful reduction in pain intensity, and patient preference for BTP medication. Adverse events were also recorded.
Results: Of the 323 patients enrolled, 203 achieved a successful dose of both study drugs, 191 completed the titration phase, and 180 completed the double-blind phase. PID(15) was significantly greater after FBT versus oxycodone (mean [SD], 0.82 [1.12] vs. 0.60 [0.88]; 95% confidence interval [CI] = 0.18, 0.29; P < 0.0001). Secondary efficacy measures favored FBT and showed differences versus oxycodone from 5 minutes postdose for PID and 10 minutes postdose for pain relief. SPID(30) and SPID(60) were greater with FBT than with oxycodone (P < 0.0001 for both measures). A ≥33% improvement in pain intensity occurred in a larger proportion of FBT-treated episodes versus oxycodone beginning 15 through 45 minutes postdose (P < 0.05). FBT was preferred by 52% of patients, oxycodone by 33%. Adverse events with both study drugs were generally typical of opioids, and the majority occurred during titration. Two serious adverse events (pneumonia) were reported in 1 patient; both occurrences were considered unrelated to study drug.
Conclusion: FBT resulted in more rapid onset of analgesia and was generally well tolerated in comparison with oxycodone for the treatment of BTP in opioid-tolerant patients.