Initial titration with 200μg fentanyl buccal tablets: a retrospective safety analysis in Korean cancer patients

Background/Aims: Managing breakthrough pain (BTP) is important for many cancer patients because of the rapid onset and unpredictable nature of the pain episodes. Fentanyl buccal tablets (FBTs) are a rapid-onset opioid indicated for BTP management. However, FBT titration is needed to optimize BTP management. In this study, we aimed to evaluate the safety and efficacy of initiating $200{\mu}g$ FBTs in Korean cancer patients. Methods: A retrospective analysis of medical records was performed on all advanced cancer patients treated with FBTs for BTP between October 2014 and July 2015. Patients who received initial doses of $200{\mu}g$ FBTs for at least 3 days and cases in which FBT was available at doses of 200, 400, and $800{\mu}g$ were included. Results: A total of 56 patients with a median age of 62 years (range, 32 to 80) were analyzed, 61% of whom were male. The median and mean values of morphine equivalent daily doses were 60 mg/day (range, 15 to 540) and $114.8{\pm}124.8mg/day$, respectively. The most frequent effective doses of FBT were $200{\mu}g$ (41 patients, 74%) and $400{\mu}g$ (12 patients, 21%). Three patients (5%) could not tolerate $200{\mu}g$ of FBT and discontinued treatment. Nausea, vomiting, somnolence, and dizziness were the most frequent treatment-related adverse events (AEs), and all AEs were grade 1 (mild) or 2 (moderate). Conclusions: FBT at the initial $200{\mu}g$ dosage was well-tolerated and effective as a BTP management strategy in Korean cancer patients. Further prospective studies are needed to determine appropriate initiating doses of FBT in Korean patients with opioid tolerance.