Analysis of prescription pattern of the fentanyl citrate sublingual tablets according to liver or kidney function abnormality of cancer patients.

Abstract

119 Background: Many advanced cancer patients eventually develop liver dysfunction or renal insufficiency during the course of their disease. However, there is limited evidence for optimally safe drug for pain control in these situation. To estimate the safety of fentanyl citrate sublingual tablets (FSTs) in kidney or hepatic dysfunction, we analyzed whether the total prescription dose or prescription period of FSTs is associated with their liver function test (LFT) or estimated glomerular filtration rate (eGFR). Methods: We retrospectively enrolled consecutive cancer patients who prescribed FSTs at least once from July 2015 to June 2017. Results: Total 611 patients were identified. Median age was 63.6 (18-89) years. Total dose of prescribed FSTs is vary widely among pts; mean 23330 ± 42111 mcg, median 8400 mcg. About kidney function, eGFR could be calculated in 523 patients (85.6%). In 80 pts (15.3%), eGFR is below 60 mL/min/1.73 m2. The total dose of prescribed FSTs have no significant correlation with grade of CKD. The duration of prescription of FSTs was shorter in patients with eGFR < 60 in compared to those with eGFR ≥60; median 42 days versus 66 days (p < 0.001). On the other hand, 535 pts (87.6%) have result of LFT prior to be prescribed FSTs. Significant LFT abnormality is found in 158 pts (29.5%). The total dose of prescribed FSTs have weak negative correlation with LFT level (p < 0.001). The total dose of FSTs is significantly lower in pts with G3/4 LFT abnormality in compared to those with normal or G1/2 LFT abnormality. The duration of prescription of FSTs was significantly shorter in patients with G3/4 liver dysfunction in compared to those with normal or G1/2 liver dysfunction; median 30 days versus 83 days (p = 0.002). In the multivariate analysis, both G3/4 LFT and decreased eGFR are significant factors for shorter duration of prescription by the Cox proportional hazard model. Conclusions: When cancer patients have renal insufficiency or significant liver dysfunction, FSTs were used in a smaller dose for a shorter period of time. We need prospective study on the efficacy and safety of FSTs in cancer patients with liver dysfunction or renal insufficiency.