Drug use evaluation of transdermal fentanyl in a tertiary hospital

The primary objective of the study was to assess the rationale of fentanyl patch initiation and continuation for pain. The secondary objectives were to analyse prescribing pattern between disciplines, monitoring criteria and adverse events profile of fentanyl patch in the inpatient wards for a tertiary hospital.

A retrospective case series review was undertaken of patients who received transdermal fentanyl for pain from April to June 2013 at the National University Hospital, Singapore. Relevant data were collected from electronic and physical medical records and audit criteria applied for indication, opioid tolerance, dosage regimen, adverse events and monitoring criteria.

40 patients were prescribed fentanyl patches for pain in the study period. 15 patients (62.5%) had one or more problems during initiation of fentanyl patch. Appropriate use during initiation was low with only 9 (38%) patients meeting all the required criteria. Most of the inappropriate use involved a lack of bridging opioids (58%), wrong opioid conversion dose (42%) and use in opioid-naïve patients (42%). In addition, three cases of inappropriate placement were observed. Monitoring for efficacy and adverse effects generally met audit criteria. There was a low incidence of discontinuation (21%) due to its well-tolerated side effect profile.

This study highlighted high incidence of inappropriate initiation of fentanyl patch, and we proposed an in-house guideline to aid physicians in initiating fentanyl patches during admission and to educate nursing staff of the monitoring parameters for efficacy and toxicity.