Transdermal therapeutic fentanyl-system (TTS-F)

Fentanyl, a surgical analgesic and general anaesthetic, is a lipophilic short-acting synthetic opioid, having a selective potent effect on mu receptors. The transdermal therapeutic fentanyl-system (TTS-F) allows for a continued and sustained titratable amount of fentanyl to be delivered without the inconvenience of the typical 24-h administration of other analgesics. Although incidences of respiratory depression led to TTS-F being contraindicated for postoperative analgesia, it is currently undergoing Phase III trials for nociceptive, neuropathic and chronic moderate to severe pain in a variety of settings. It demonstrates a slow pharmacokinetic profile and incidences of breakthrough pain may still require rapid analgesia, for which intravenous and bolus administration of rapid acting opioids remain 'gold standard'. However, TTS-F is finding uses for chronic pain of cancer origin where it offers a solution for step 3-pain (WHO) management on the WHO analgesic ladder. More recent data indicates that TTS-F is not only effective for neuropathic but also nociceptive non-cancer and cancer pain alike. This review presents an overview of the synthesis, delivery, pharmacokinetics, toxicity and clinical pharmacology of the transdermal delivery of fentanyl.