Effectiveness and Safety of Sublingual Fentanyl in the Treatment of Breakthrough Cancer Pain in Older Patients with Cancer: Results from a Retrospective Observational Study.

The study assessed sublingual fentanyl citrate (SFC) effectiveness and safety for breakthrough cancer pain (BtCP) in older patients. A multicenter, retrospective, observational study was conducted in three subgroups of cancer patients aged over 65 years with BtCP. The reports were collected by 20 oncologists across 12 hospitals. The primary goal was to measure changes in BtCP intensity with SFC treatment over 30 days; secondary objectives included pain relief onset and adverse events. A total of 127 patients with long-term cancer (mean: 3.3 years) were recruited. All of them had BtCP, mostly of mixed origin (62.5%). A significantly lower dose was needed in the high-age group at the final visit compared to baseline (212.90 ± 200.45 mcg vs. 206 ± 167.08 mcg; p = 0.000). Pain intensities at the beginning of the flare and at 30 min after SFC administration were significantly lower when the last and first visits were compared (1.9 vs. 2.3, p = 0.000; and 6.2 vs. 6.8 p = 0.006, respectively). The onset of analgesia was significantly more rapid for half of the patients ≥75 years, compared with 65-69 and 70-74 age groups. SFC appears then to be effective, well-tolerated, and safe to treat BtCP in older cancer patients.