ANESTA/ABBOTT ORALET ORAL TRANSMUCOSAL FENTANYL APPROVED OCT. 4

ANESTA/ABBOTT ORALET ORAL TRANSMUCOSAL FENTANYL APPROVED OCT. 4 for anesthetic premedication in children and adults and for use in anesthesia or monitored anesthesia care, approved labeling states. Oralet was classified "3P" by FDA, designating a new formulation of an already approved drug given priority review by FDA.

The approval of the fentanyl lozenge molded on a radiopaque plastic handle comes a little more than a month after a joint FDA advisory committee recommendation for approval on Aug. 24 ("The Pink Sheet" Aug. 30, p. 12). Salt Lake City-based Anesta submitted an amended application for the novel version of the scheduled anesthetic in December 1992. FDA's approval letter notes that the NDA (20-195) was filed on May 24 and an amendment to the NDA was received on Sept. 2.

Anesta's Oralet is being manufactured and distributed by Abbott, which has worldwide rights to the fentanyl lozenge. Abbott plans to "introduce" Oralet Oct. 10 during the American Society of Anesthesiologists annual meeting in Washington, D.C. The drug will be available after Dec. 1.

Oralet is a Schedule II narcotic. Because it is a controlled drug and is transmucosally administered, the warnings section of labeling contains a "black box" that emphasizes the need for close monitoring and cautions that Oralet "delivers full doses of the potent opioid narcotic fentanyl and carries a risk of hypoventilation with its use."

Hypoventilation occurred in clinical trials of Oralet in 11% of patients. Other dose-related events associated with the administration of Oralet lozenges reported at frequencies greater than 10% in clinical trials were nausea (17%), vomiting (34%), dizziness (15%) and pruritis (56%).

Because of the hypoventilation risk, Oralet is not recommended for premedication unless there is monitoring. The drug is recommended for use as an adjunct to the induction of general, regional or conduction anesthesia in doses from mild (5 mcg/kg) to marked (15 mcg/kg).

In addition to the "black box" warning, labeling emphasizes throughout that Oralet must be used only in a closely clinically monitored situation to minimize the risk of hypoventilation. The drug "is not recommended for use in solo practice situations or in unmonitored settings" such as "dental offices without monitored anesthesia care, surgical settings without an anesthetist, single- operator endoscopy suites and radiological settings where access to the patient is restricted by the equipment."

Oralet can be used as premedication to prevent anxiety or fearfulness in children and adults or to manage a fearful patient. In clinical trials, doses of 5-10 mcg/kg of Oralet reduced the number of children fearful at 30 minutes from 42% in the placebo group to about 7% in the Oralet group, labeling states. Unmanageable fear was seen in 10%-20% of children studied in the clinical trials. Doses of 5-15 mcg/kg of Oralet "produced a dose- related reduction in apprehension that was sufficient to allow a calm, manageable induction of anesthesia within 20-30 minutes," labeling states.

The drug, while not studied in the elderly, can be used in that population, labeling notes. Geriatric patients, however, "have been shown to be twice as sensitive to the effects of other forms of fentanyl as the younger population." Labeling therefore recommends that the dose "should be reduced to 2.5-5 mcg/kg."

The agency approval letter notes the "importance" of Abbott's risk management plan submitted as part of the Oralet NDA. The plan consists of "proposed educational materials, customer targeting and inventory management controls," the letter states. "We consider the quality, content and proper implementation of this plan to be essential to the safe introduction of the product to the market and ask that it be followed in all of the proposed particulars." Abbott's anesthesia/surgical products field force will handle the in-service training and educational programs at the outset of Oralet's distribution. Anesta also agreed Oct. 1 to Phase IV commitments, which include additional studies, the approval letter notes.

Oralet is supplied as red raspberry colored lozenges in 200 mcg, 300 mcg and 400 mcg doses. Each dose is distinguished by color highlighted labels on the individually wrapped plastic handled units: yellow base for 200 mcg, green for 300 and blue for 400.