[The cognitive effects of using transdermal fentanyl in cancer pain]

In this study, we aimed to investigate the effects of using transdermal fentanyl (TDF) on cognitive functions in cancer pain.

After approval and informed consent of patients by the Ethical Committee, fifty patients with cancer pain who had no previous opioid treatments were included in the study. Pain was evaluated with Visual Analogue Scale (VAS) while, cognitive functions were assessed using by Addenbrooke's Cognitive Examination final revised version (ACE-R). In addition, performance was evaluated with Eastern Cooperative Oncology Group Performance Status (ECOG) and adverse reactions were noted. Patient algological evaluation was done in the first application and the normal cognitive functions were established using ACE-R. In most cases the treatment began with 25 µg/h TDF and, at certain stages of the treatment, the dose was increased so that VAS ≤2. ACE-R was applied again on day 30 under sufficient analgesia. All patients were compared using ACE-R total scores and subgroups (attention-orientation, memory, fluency, language, visuospatial abilities) at before and after TDF treatment.

At the end of the study, attention-orientation, memory, fluency, language, and ACER total scores showed a statistically significant improvement after TDF treatment than before. No significant change was obtained for the visuospatial abilities. No difference was detected in performance status.

The use of TDF for the treatment of cancer pain is not associated with impairment in cognitive performance. Even some cognitive test scores demonstrated significant improvement. Our data shows that the absence of pain increased the quality of life.