Evaluation of safety and efficacy of transdermal therapeutic system-fentanyl in adult patients with gynecological cancer-related pain

To assess the analgesic safety and efficacy of Transdermal Therapeutic System (TTS)-fentanyl in the treatment of chronic gynecological cancer-related pain. TTS-fentanyl is a Transdermal Therapeutic System, which contains a rate-limiting membrane that provides constant release of fentanyl. TTS-fentanyl can be properly used to control pain. Therefore, this trial was designed to establish the analgesic efficacy and safety of TTS-fentanyl in the treatment of chronic gynecological cancer-related pain. Thirty patients were recruited into the study. This open study was comprised of two phases. Phase 1: an oral morphine stabilization phase where eligible patients, who took other opioids and/or analgesic drugs, were entered into the stabilization phase and should be converted to oral morphine according to the conversion chart. The patients were then titrated to a stable oral morphine dose. Phase 2: an open TTS-fentanyl treatment phase where the daily dose of oral morphine was switched to TTS-fentanyl according to the conversion chart. The efficacy parameters of pain score were assessed by visual analogue scale (VAS) and global assessments. The safety was evaluated by monitoring the patient's clinical conditions and adverse events. TTS-fentanyl was generally well tolerated. Only one patient was dropped out from the study due to lacking enrollment in the stabilization phase. The most frequent adverse events were mild nausea or vomiting (46%) and constipation (33%). The median pain VAS during TTS-fentanyl treatment was decreased from 8 to 3 and global assessments at the end of the treatment were better than at the start of the treatment. The results suggest that TTS-fentanyl is safe and effective in managing chronic gynecological cancer-related pain.