Pfizer's opioid painkiller can be manipulated for abuse: FDA

[June 07, 2016]  By Natalie Grover

(Reuters) - Pfizer Inc's experimental long-acting opioid painkiller has some abuse-resistant properties but addicts can still extract oxycodone from the drug using certain solvents, a preliminary review by the U.S. Food and Drug Administration concluded on Monday.

Pfizer is seeking approval to claim the drug, whose proposed trade name is Troxyca ER, deters abuse. It wants to market the drug for patients with pain severe enough to require around-the-clock treatment for whom other drugs are not enough.

The review comes ahead of meeting on Wednesday of outside experts, who will discuss the drug and recommend whether it should be approved. The FDA is not obliged to follow the advice of its advisory panels but typically does.

Troxyca ER contains oxycodone and naltrexone, a drug that negates the effect of oxycodone if the pellets are crushed. (http://1.usa.gov/1UCIQUI)

Pfizer's morphine-based, long-acting painkiller Embeda uses a similar technology. The FDA approved Embeda with an abuse deterrent label in 2014.

The FDA review said oxycodone could be extracted from Troxyca ER using multiple common solvents, some more easily than others. Pfizer states in its own briefing documents that oxycodone could only be uniquely extracted, without naltrexone, using one solvent.

On Tuesday the panel will consider an abuse-resistant opioid made by Teva Pharmaceutical Industries Ltd, Vantrela ER. The FDA found the drug had abuse-deterrent properties when snorted or injected. The benefit was less clear when the product was swallowed.

Studies showed that little oxycodone is released from heated Troxyca ER vapor, reducing the likelihood of abuse by those seeking to inhale it, the reviewers said.

The abuse of opioids — a class of drugs that includes heroin and prescription painkillers — has reached epidemic proportions in the United States. The Centers for Disease Control and Prevention (CDC) estimates that 78 Americans die every day from opioid overdose.

Last week officials in Minnesota determined that the April death of musician Prince was due to an accidental overdose of the synthetic opioid fentanyl.

(Reporting by Natalie Grover in Bengaluru; Additional reporting by Toni Clarke in Washington; Editing by Saumyadeb Chakrabarty and Matthew Lewis)

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