Pfizer is the latest company to win approval of opioid abuse-deterrent labeling, after the FDA cautiously OK’d new statements about Embeda.

The new labeling, coming early next year, will mention properties that the company expects will make the drug less vulnerable to oral, intranasal or intravenous abuse when crushed. 

The abuse-deterrent property in Embeda is naltrexone — an opioid antagonist often used as an antidote to overdose that may block some of the euphoria induced by the morphine opioid component.

But while multiple clinical studies showed that, in general, the amounts of morphine and naltrexone released upon crushing Embeda (morphine sulfate and naltrexone HCl) were less likely to produce a high compared with morphine alone, Pfizer says that only postmarketing data will paint a true picture of Embeda’s oral and intravenous abuse potential.

The FDA has asked the company to conduct postmarketing studies to gain a more realistic handle on that potential. At the same time, agency admits that naltrexone is not expected to do much to block morphine-induced euphoria in intact Embeda.

“All abuse-deterrent labeling includes language that abuse potential is still possible,” Pfizer spokesman Steven Danehy said. Like any other prescription opioid, he said Embeda can never be entirely abuse-proof.

Embeda was originally approved in August 2009 for pain severe enough to require daily, round-the-clock opioid treatment that is resistant to other treatment options, but was taken off the market in March 2011, due to concerns over manufacturing stability. Those concerns were resolved in November of last year via a manufacturing supplement, according to the FDA. — Lena Freund

Originally appeared in Drug Industry Daily, the pharmaceutical industry’s number one source for regulatory news and information. Click here for more information.