Efficacy and safety of sublingual fentanyl tablets for the management of breakthrough pain in patients with chronic musculoskeletal pain with neuropathic component: multicenter prospective study.

Background And Objective: Despite its prevalence and impact, breakthrough pain (BTP) in chronic non-cancer pain with neuropathic component, has not been well studied and is sometimes unrecognized and often undertreated. We evaluated the efficacy of sublingual fentanyl tablet (SLF) for the treatment of BTP in opioid-tolerant patients with chronic musculoskeletal pain with neuropathic component in terms of relief of pain intensity and assessed whether hypothetical pain relief impacts on quality of life (QoL).

Methods: A multicenter, prospective, open-label study was conducted over a 30-day period. Efficacy was evaluated using a visual analogue scale (VAS) and time to onset of action of SLF. The incidence of dependence was assessed by the Leeds Dependence Questionnaire (LDQ). Changes in QoL were evaluated using the Brief Pain Questionnaire (BPI) and the EuroQol (EQ-5D). Adverse events (AE) were recorded throughout.

Results: 106 patients were enrolled and 105 completed the study. The average pain reduction across the study was -3.30 points [95 % confidence interval (CI) 2.9-3.7; P < 0.0001]. Pain intensity improvement from baseline was statistically significant at first assessment and all subsequent assessments (P < 0.0001). The most common AEs included nausea (33.87 %), constipation (33.06 %), somnolence (19.35 %) and vomiting (6.45 %). No significant differences were observed on LDQ (P = 0.71). QoL as measured by BPI showed statistically significant improvement in all four severity items and all interference items (P < 0.0001) and a significant improvement in the percentage of pain relief reported by patients (P < 0.0001). EQ-5D results showed a trend towards improvement. Mean self-rate health status, as measured by the EQ VAS scale increased significantly (P < 0.0001).

Conclusion: SLF provides significant reductions in BTP intensity. The results of the BPI and EQ-5D assessments indicate that pain relief is associated with improvement of functioning and enhancement of QoL.