The Food and Drug Administration on Friday approved the first pure hydrocodone drug in the United States. The drug, Zohydro ER (extended release), was approved for patients with pain that requires daily, around-the-clock, long-term treatment that cannot be treated with other drugs.

Drugs such as Vicodin contain a combination of hydrocodone and other painkillers such as acetaminophen, the Associated Press reports.

In December, a panel of experts assembled by the FDA voted against recommending approval of Zohydro ER. The panel cited concerns over the potential for addiction. In the 11-2 vote against approval, the panel said that while the drug’s maker, Zogenix, had met narrow targets for safety and efficacy, the painkiller could be used by people addicted to other opioids, including oxycodone.

Patient safety advocates criticized the FDA’s decision. “We’re just going to kill more kids and then the FDA is going to come back and say, ‘oh, we made a mistake,’” said Avi Israel, whose son Michael committed suicide while struggling with painkiller addiction. Israel is the founder of a group that aims to combat painkiller abuse in young people.

In a statement, the FDA noted, “Zohydro ER will offer prescribers an additional therapeutic option to treat pain, which is important because individual patients may respond differently to different opioids.”

The agency will require postmarketing studies of Zohydro ER to evaluate the known serious risks of misuse, abuse, increased sensitivity to pain, addiction, overdose, and death associated with long-term use beyond 12 weeks.