Oral transmucosal fentanyl citrate: overview of pharmacological and clinical characteristics.

Oral transmucosal fentanyl citrate (OTFC; brand name Actiq, Cephalon, UT) is a new opioid formulation that incorporates fentanyl into a lozenge and allows drug delivery through the buccal mucosa. This kind of absorption avoids first-pass metabolism, yielding a bioavailability substantially greater than oral administration. OTFC has a rapid onset of action and a short duration of effect. These characteristics, which resemble the course of a typical breakthrough pain episode, resulted in making OTFC the first opioid analgesic formulation specifically developed and approved for control of breakthrough pain in cancer patients. Apart from that, OTFC has been used in a variety of clinical situations of noncancer pain. This review article presents the synthesis; clinical pharmacology; pharmacokinetic and pharmacodynamic properties, toxicity, and clinical efficacy of this novel agent.