FDA staff cite abuse concern with Alpharma drug

By Susan Heavey

WASHINGTON (Reuters) - Alpharma Inc's powerful painkiller Embeda may not thwart drug abusers despite design features aimed at curbing misuse, U.S. regulatory staff said in documents released on Wednesday.

The drugmaker tested the effects of the design features only when the pill was misused orally, but addicts tend to crush such morphine-based drugs and then inject them, U.S. Food and Drug Administration staff said.

"It is unknown what the potential effects of injecting this product following manipulation" might be, they wrote.

Alpharma, the target of a hostile takeover bid from King Pharmaceuticals Inc, is seeking U.S. Food and Drug Administration approval to market the extended-release drug for moderate to severe chronic pain, saying a special formulation makes it tougher to abuse.

On Friday, FDA officials will ask for advice from an advisory panel on whether to allow the drug. The agency usually follows the advice of its outside experts.

Embeda capsules include an inner core of naltrexone, a drug used to offset the powerful narcotic. The core kicks in if the capsule is crushed or dissolved, but does not counteract the morphine if the capsule is taken as directed, Alpharma said in separate documents.

Morphine-based drugs are often sought by drug abusers. Pills can be crushed or dissolved and then snorted or injected for a quick high.

Alpharma and other drugmakers are trying to develop new types of drugs that are not as easily manipulated by drug abusers.

On Thursday, the FDA panel will weigh the risks and benefits of Remoxy, a gel-based extended-release version of oxycodone, developed by King and Pain Therapeutics Inc, that aims to be less easily abused than tablet alternatives.

Opioid painkillers are extremely potent and can only be prescribed by doctors who register with the U.S. Drug Enforcement agency. However, drug abusers are still able to obtain and misuse them.

Shares of Alpharma were up nearly 4 percent at $29.98 in morning trade, while shares of King were up 7 cents at $10.08, both on the New York Stock Exchange.

The documents on Embeda were posted on the FDA's website here

(Reporting by Susan Heavey; editing by John Wallace)