Opioid painkiller manufactured by Pfizer can be manipulated for abuse, the U.S. Food and Drug Administration (FDA) review has found.
On June 6, the FDA concluded its preliminary review of Pfizer's experimental opioid drug, Troxyca ER. FDA officials found that while the drug indeed has properties that prevent abuse, oxycodone can still be extracted using solvents.
The result of the preliminary review was released prior to the scheduled Joint Meeting of the Anesthetic and Analgesic Drug Products Advisory Committee and the Drug Safety and Risk Management Advisory Committee on June 8, where industry experts will convene and discuss whether the drug should be approved [PDF] or not.
The FDA has previously approved six long-acting or extended-release opioid painkillers that also have abuse-deterrent properties. However, the agency is yet to approve immediate-release opioid drugs that are in a single-dose or combination (opioid/non-opioid) preparation.
Pfizer submitted its long-acting opioid drug for review because the company wants to sell it as a treatment for patients with severe pain requiring continuous treatment without the risk of abusing it.
Troxyca ER's opioid antagonist comes in the form of naltrexone. When the drug coated with oxycodone is crushed, naltrexone acts by countering the effect of oxycodone. The reviewers did reveal that heating Troxyca ER releases only trace amounts of oxycodone.
In the review [PDF], the FDA said the extraction can be easily done using several solvents that are commonly available. But Pfizer contested that the extraction is only possible by one, unique solvent.
When Troxyca ER is taken orally, it can provide the least amount of naltrexone. However, the agency found that chemical and/or physical manipulation of the capsules or pellets can remove naltrexone and heighten the effect of oxycodone.
Pfizer has a long-acting, morphine-based drug — Embeda — that was previously approved by the FDA in 2014.
The advisory committee would now vote whether Troxyca ER should be approved and through what route of administration.
The FDA has earlier approved the use of Probuphine implant to treat opioid dependence.