Efficacy of fentanyl iontophoretic transdermal system in postoperative pain—A meta-analysis

Summary Background Postoperative analgesic modalities include patient-controlled techniques via various routes such as intravenous and epidural. A transdermal delivery route using iontophoretic technology appears promising. Recent randomised controlled trials have suggested that fentanyl iontophoretic transdermal system (ITS) was of equivalent efficacy to intravenous morphine patient-controlled analgesia (PCA). The objective of this meta-analysis was to assess the efficacy and safety of this system in the management of acute postoperative pain. Methods A meta-analysis of two placebo-controlled and four active-controlled randomised trials which satisfied the inclusion criteria was performed according to the QUOROM guidelines. Results Fentanyl ITS was superior to placebo for postoperative analgesia using withdrawal secondary to inadequate analgesia and pain scores as outcome measures. Fentanyl ITS was equivalent to morphine PCA when Patient Global Assessment was used as primary outcome measure. However, there were significantly more patients in the fentanyl ITS group who withdrew due to inadequate analgesia. This may be related to the pharmacokinetic profile of fentanyl ITS. Adverse effect and safety profile seemed favourable. Conclusions Fentanyl ITS is a promising novel modality for postoperative analgesia that is superior to placebo but may not be equivalent to morphine PCA as claimed by individual trials and recent reviews. Its use appears to be safe.