A Review of Oral Transmucosal Fentanyl Citrate: Potent, Rapid and Noninvasive Opioid Analgesia

Abstract

The physiochemical characteristics of the potent synthetic opioid agonist fentanyl make it ideal for noninvasive transmucosal delivery. Studies of oral transmucosal fentanyl citrate (OTFC), a candied matrix formulation administered orally as a palatable lozenge on a stick, have investigated and determined this analgesic's pharmacokinetics and pharmacodynamics in a number of clinical settings, including premedication before surgery, acute analgesia for painful medical procedures, and, most recently, for the control of breakthrough cancer pain. The onset to meaningful pain relief in patients with acute pain from surgery or breakthrough pain from cancer is between 5 and 10 minutes after initiating OTFC use, equivalent to intravenous morphine. Analgesic dose equivalency studies suggest that OTFC is, on average, about 10 times more potent than morphine, although, in randomized, controlled, and blinded studies, many patients who were using relatively high doses of opioid anlagesics on an around the- clock schedule for control of cancer pain reported that even a low dose of OTFC (i.e., 200 microg) provided adequate relief from breakthrough pain. Side effects from OTFC are similar in character and frequency to other opioids, including sedation, nausea, and pruritus. These effects appear to wane rapidly with repeated use of this medication. To date there have been no reported serious adverse events in any of the population groups studied or treated with OTFC.