my personal edition > pain > news


  E-Mail this DGNews to a colleague

DGNews

FDA Approves Tamper-Proof Long-Acting Opioid for Management of Moderate to Severe Chronic Pain

BRISTOL, Tenn. -- August 13, 2009 -- The US Food and Drug Administration (FDA) has approved morphine sulfate/naltrexone hydrochloride (Embeda), an extended-release oral opioid analgesic for the management of moderate to severe pain when a continuous, around-the-clock opioid analgesic is needed for an extended period of time. This Schedule II agent is the first FDA-approved long-acting opioid that is designed to reduce drug liking and euphoria when tampered with by crushing or chewing.

Each capsule contains extended-release morphine pellets, each with an inner core of naltrexone hydrochloride, an opioid receptor antagonist. If taken as directed, the morphine relieves pain while the sequestered naltrexone hydrochloride passes through the body with no intended clinical effect. If the capsule is crushed or chewed, the naltrexone is released and absorbed with the morphine, reversing the morphine's subjective and analgesic effects.

"The development of formulations like Embeda that employ technologies designed to reduce drug liking and euphoria associated with non-medical uses could potentially change how chronic pain is treated. Prescribers and patients have been hoping and waiting for safer medicines to treat chronic pain," said Nathaniel Katz, MD, MS, Tufts University, Boston, Massachusetts.

The FDA approval was based on data from 12 clinical studies of morphine sulfate/naltrexone hydrochloride, including phase 3 data demonstrating efficacy and safety. In a phase 3 study, morphine sulfate/naltrexone hydrochloride provided significant pain relief in patients with moderate to severe pain due to osteoarthritis of the hip or knee compared with placebo. Additionally, an earlier phase 2 study found morphine sulfate/naltrexone hydrochloride was bioequivalent to another marketed extended-release morphine sulfate capsule product.

Phase 3 findings also showed that morphine sulfate/naltrexone hydrochloride was safe and well tolerated in patients treated for up to 12 months, with an overall safety profile consistent with the most common opioid-related adverse events. The most common adverse events reported were consistent with the well-known adverse reactions associated with morphine, including constipation, nausea, and somnolence.

The data also showed that sequestered naltrexone hydrochloride did not compromise the safety and efficacy of the morphine. In a separate study of recreational drugs users, morphine sulfate/naltrexone hydrochloride, when crushed and taken orally, was shown to have reduced drug liking and euphoria compared with an equivalent dose of immediate-release morphine sulfate solution. The clinical significance of the degree of reduction in drug liking and euphoria reported in these studies has not yet been established. There is no evidence that the naltrexone in the capsule will reduce the abuse liability of the agent.

SOURCE: King Pharmaceuticals, Inc.

E-Mail this DGNews to a colleague

To print, use this version