Fentanyl buccal tablet: in breakthrough pain in opioid-tolerant patients with cancer.

The fentanyl buccal tablet (FBT) is a new formulation of fentanyl that uses an effervescent drug delivery system to enhance penetration across the buccal mucosa for the treatment of breakthrough pain in opioid-tolerant patients with cancer. Fentanyl is rapidly absorbed from FBT across the buccal mucosa and into the bloodstream. Fentanyl is more rapidly absorbed and bioavailability is higher from FBT than from the oral transmucosal fentanyl citrate formulation. In a well designed phase III trial in opioid-tolerant patients with cancer, a single dose of FBT 100-800 microg provided clinically significant improvements in pain intensity from 15 to 60 minutes after the dose. Single FBT doses of 100-800 microg were generally well tolerated; the majority of adverse events were mild to moderate in nature and typical of those associated with opioids.