Predicting tolerability of high-dose fentanyl buccal tablets in cancer patients

Background & aims Fentanyl buccal tablets (FBTs) are a rapid-onset opioid indicated for breakthrough cancer pain (BTcP) and FBT titration is needed to optimize BTcP management. We aimed to predict which patients could tolerate a high dose of FBT (400 μg or more at a time). Methods A retrospective analysis was performed to assess the final FBT dose. The final FBT doses were compared according to the clinical features. The prediction accuracy of patients tolerant of 400 μg or higher FBT was compared using the area under the receiver operating characteristic (ROC) curves. A risk scoring model based on the odds ratio (OR) was developed from the final multivariable model, and patients were assigned into two groups: low tolerance (0–1 point) and high tolerance (2–3 points). Results Among 131 patients, the most frequently effective dose of FBT was 200 μg (54%), followed by 100 μg (30%). The median value of morphine equivalent daily doses (MEDD) was 60 mg/ day, and the most common daily use was 3–4 times/day. In multivariable analysis, male sex, younger age, and use of FBTs three or more times per day were independently associated with high-dose FBT. According to the risk scoring model, the patients with a final FBT of 400 μg or higher were significantly more in the high tolerance group (17%) compared to the low tolerance group (3%; p = 0.023) Conclusions According to the dose relationship between the final FBT dose and the clinical features, three factors (sex, age, daily use of FBT) were independently associated with the final dose of FBT. Our risk score model could help predict tolerance to high-dose FBT and guide the titration plan for BTcP.