Studies confirm effectiveness of fentanyl lozenges for 'breakthrough' cancer pain

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Breakthrough pain is moderate to severe sudden pain that interrupts otherwise controlled, persistent pain in people already taking pain medicine. The fentanyl lozenge, known as oral transmucosal fentanyl citrate, or OTFC, is also known by the brand name Actiq.

The review comprised four randomized controlled trials of a total 393 patients with cancer. Patients received OTFC for breakthrough pain and relief was compared with morphine or other opioid rescue medication, or placebo.

The review appears in the most recent issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.

OTFC was specifically developed for breakthrough pain and approved by the FDA in 1998, and is used only by patients who are already taking other narcotic pain medications. It is exponentially more potent than morphine.

Current treatment for breakthrough pain typically involves so-called "rescue medication" - a supplemental dose of a patient's current pain medication. The review findings showed that fentanyl is more effective.

Forty-eight study patients who previously used narcotics other than morphine were able to find a safe and effective dose of fentanyl and rated it as better for breakthrough than their usual rescue pain medication; 93 patients who traditionally used morphine reported a 33 percent higher change in pain intensity and pain relief at 15 minutes with fentanyl; and 93 of 130 patients who received fentanyl found a safe and effective dose and rated the drug higher than placebo for relief.

"OTFC was reported to produce a greater analgesic effect, better global satisfaction and a more rapid onset of action than the usual rescue medication or placebo," the authors conclude.

According to Zeppetella, the superior results may be due to a number of factors. "The faster onset and shorter duration of action of OTFC more closely match the characteristics of most breakthrough pain," Zeppetella said. The lozenge is placed within the cheek and gum, a site that "has a wide surface, is well-vascularized and facilitates absorption." The lozenge dissolves within 10 minutes, with only about 5 percent remaining. The medicine is then quickly absorbed and moved into the central nervous system to quell pain, Zeppetella said.

Despite the positive outcomes, treating breakthrough pain is ultimately a matter of customizing treatment for each patient, depending on the specific cause and site of the breakthrough pain, Zeppetella said. "The ideal treatment for breakthrough pain is an analgesic with good efficacy, a rapid onset of action, a short duration of action and minimal adverse effects. Irrespective of the drug, the pharmacokinetic profile will need to match the characteristics of breakthrough pain."

Another expert agrees that OTFC is not the only or definitive treatment for cancer pain. "This review mostly points out the paucity of appropriate studies of breakthrough pain," said Charles F. von Gunten, M.D., editor in chief of the Journal of Palliative Medicine. He noted that the review is not a comprehensive study of all opioids; rather, "it is only four studies of OTFC." He said, "The principal barrier to adequately treating breakthrough pain is accurate diagnosis and the utilization of existing medications in appropriately aggressive ways."

Side effects of fentanyl include dizziness, feeling faint, lightheadedness, unusual tiredness or weakness, shortness of breath, anxiety, confusion or hallucinations. Less serious side effects include constipation, dry mouth and nausea or vomiting.

Center for the Advancement of Health