WASHINGTON (AP) -- The head of the Food and Drug Administration said Thursday that the much-debated painkiller Zohydro fills an "important and unique niche" for treating pain.
Dr. Margaret Hamburg defended her agency's decision to clear the drug during questioning before the Senate's committee on health, saying that the pill from Zogenix Inc. met the government's standards for safety and effectiveness.
Zohydro is the first FDA-approved version of pure hydrocodone, the most abused prescription substance in the U.S. Previously the drug was only available in combination pills like Vicodin, which mix hydrocodone with other pain relievers like acetaminophen. But Hamburg pointed out to Senators that acetaminophen has its own well-known safety risks, including potentially deadly liver damage when taken at high levels. Zohydro provides doctors and patients with a "single hydrocodone product without that associated liver toxicity risk," Hamburg said.
Since its approval in December, more than a half-dozen lawmakers have sent letters to the agency questioning its review of Zohydro. Chief among the criticisms leveled at the agency is that FDA regulators should have required Zohydro to be formulated in a way that would make it difficult for abusers to crush or dissolve, for snorting or injection.
Hamburg cautioned that such formulations are still in the early stages of development. To date, the FDA has only approved one medication with such features, a tamper-resistant version of OxyContin launched in 2010.
"It doesn't do any good to label something as abuse deterrent if it isn't actually abuse deterrent, and right now, unfortunately, the technology is poor," Hamburg said.
On Wednesday Purdue Pharma, the maker of OxyContin, announced it would submit an abuse-deterrent version of hydrocodone to the FDA for review later this year. The news sent shares of San Diego-based Zogenix Inc. down more than 20 percent in trading, on expectation that Purdue's product could derail sales of Zohydro.
Pharmacies began dispending the drug this week.