Cancer Patients Fare Well on High-Dose Sublingual Fentanyl

Laird Harrison

May 25, 2012

May 25, 2012 (Honolulu, Hawaii) — Patients experiencing breakthrough cancer pain fared best on relatively high doses of sublingual fentanyl spray, a new study shows.

The recently introduced sublingual spray (Subsys, Insys Therapeutics) acts faster than tablet, film, and lollipop formulations, researcher Lisa Stearns, MD, told Medscape Medical News.

"This drug has a high peak, then comes down," said Dr. Stearns, an anesthesiologist who directs the Center for Pain and Supportive Care in Scottsdale, Arizona. Pain relief starts about 5 minutes after administration and lasts for about an hour, she said.

Dr. Stearns and other researchers presented 3 studies funded by Insys on the company's new fentanyl formulation here at the American Pain Society (APS) 31st Annual Scientific Meeting.

Breakthrough Pain

In a titration study, 130 patients who experienced breakthrough cancer pain started on a dose of 100 mcg for 2 consecutive breakthrough cancer pain episodes. Those who had taken fentanyl in another formulation started at 200 mcg.

If those treatments were not successful, investigators increased the dose for the next 2 breakthrough episodes, up to a maximum of 1800 mcg.

Three patients could not reach a satisfactory dose. Another 29 patients dropped out of the study before they could determine whether any dose would satisfy them.

Among the remaining 98, the most common successful doses were 800 mcg, which satisfied 24.5% of patients, and 1200 mcg, which satisfied 20.4%.

A second study used the Treatment Satisfaction Questionnaire for Medication to evaluate patients' satisfaction with their existing treatment for breakthrough cancer pain before they began taking the sublingual fentanyl spray, and again after they had been titrated to the new drug.

This study showed that 87.5% said that sublingual fentanyl spray relieved their symptoms, while 27.3% said their usual drug relieved their symptoms.

Of those receiving the sublingual spray, 30.0% said it interfered with their thinking vs 72.7% with the usual drug.

Six patients dropped out of the titration study because of adverse events, and at least 7.7% experienced adverse events that the investigators thought were at least possibly related to the drug, such as nausea, somnolence, dizziness, and vomiting.

Finally, the third study looked at adverse events during a 90-day maintenance period. In that study, investigators estimated that 24.5% of patients had adverse events that could be related to the medication. The median dose was 600 mcg.

Patients can use sublingual fentanyl spray along with other opioids, such as oxycodone, Dr. Stearns said.

It has the advantage of acting more quickly than tablets that have to dissolve in the mouth, she added. Patients using the tablets often swallow a lot of the drug, rendering it less effective than if they had absorbed it through their mucosa, and the onset varies from one patient to another depending on the acid balance of their saliva, she said.

Patients who are susceptible to incident pain, such as from jostling, can use the sublingual spray just before they anticipate such an event, she said. For example, they can take it before driving or going to a medical appointment.

Loss of Sensation

A disadvantage of this method of administration is that patients who have lost sensation in their hands may have difficulty manipulating the spray bottle, said Dr. Stearns.

The bottle also takes more space than do a few tablets, added Edward Michna, MD, JD, an anesthesiologist at Brigham & Women's Hospital in Cambridge, Massachusetts, who was not involved in any of these studies.

He wondered if women might be more willing to use it than men because they carry purses.

More important, he wondered how much difference the quicker onset might make. "Is that difference of 5 minutes onset really meaningful?" he asked.

Finally, he said the market would be limited because the drug is expensive.

"It appears to be yet another improvement in terms of analgesic relief," he told Medscape Medical News. "But it comes with limitation due to its cost."

Dr. Stearns has disclosed no relevant financial relationships. Dr. Michna disclosed that he has had financial relationship with Insys and other pharmaceutical companies.

American Pain Society (APS) 31st Annual Scientific Meeting. Abstract #353, #354, and #355.


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