Effect of fentanyl buccal tablet on pain-related anxiety: a 4-week open-label study among opioid-tolerant patients with chronic and breakthrough pain.

OBJECTIVE: To evaluate the effect of fentanyl buccal tablet (FBT) on pain-related anxiety in opioid-tolerant patients with chronic pain and breakthrough pain (BTP). DESIGN: This study consisted of a screening visit, open-label titration period, and 4-week open-label treatment period. SETTING: Thirty-one US study centers. PATIENTS: Opioid-tolerant adults with chronic, persistent pain experiencing 1-4 BTP episodes per day at baseline. Two hundred eighteen patients were enrolled in this study; 180 completed the titration period; and 169 completed the treatment period. INTERVENTION: Patients were treated with FBT (100-800 microg) for BTP episodes for 4 weeks while continuing their around-the-clock opioid regimens. MAIN OUTCOME MEASURES: Change from baseline in the Pain Anxiety Symptoms Scale (PASS) total score at the final visit. RESULTS: Based on a mean baseline PASS total score of 82.6, study patients had a high level of anxiety; 92 patients (42 percent) had a history of anxiety disorders. The change from baseline in PASS total score was not statistically significant (mean change, -1.6; p = 0.322). Numerical improvements were reported in some secondary measures (eg, Beck Depression Inventory total score /mean change, -1.1; p = 0.038) and categorical measures (eg, Pain Flare Treatment Satisfaction, Patient Assessment of Function, and Clinician Assessment of Patient Function ratings). FBT was generally well tolerated, with no serious adverse events related to study drug. CONCLUSIONS: Four weeks of treatment with FBT did not reduce anxiety to a clinically meaningful extent, although improvement was reported in several secondary measures of functioning. Further research is needed to assess the impact of treatment for BTP on anxiety symptoms in opioid-tolerant patients with BTP.