In a 12-1 vote, the Food and Drug Administration (FDA) approved the use of Vivitrol to treat addiction to opiates like heroin and prescription painkillers, ABC News reported Oct. 13.

Vivitrol, a form of naltrexone manufactured by Alkermes, is already used to treat about 10,000 patients a year for alcoholism. Though available in pill form, it is usually administered as a monthly shot, and can be prescribed by physicians.

Naltrexone works by blocking opioid receptors in the brain, ensuring that patients will not feel any effects if they attempt to use while being treated. Over time, their cravings diminish. By contrast, methadone is used as a replacement drug for opiates — users can still be addicted to it — and buprenorphine blocks some receptors, but not all. 

The FDA said it based its approval of Vivitrol on studies showing that 36 percent of those treated remained in treatment for six months, compared to 23 percent of those on a placebo. Possible side effects include depression, suicide, liver damage and a reaction at the injection site serious enough to require surgery. 

Vivitrol was approved for use to treat alcoholism in 2006, but according to an Oct. 12 CNN blog post, insurance companies generally do not pay for it. Shots cost about $1,000 each, and treatment can take over a year. According to doctors interviewed by CNN, Vivitrol is not meant to be used alone, but as part of a larger treatment plan.   

“Addiction is a serious problem in this country, and can have devastating effects on individuals who are drug-dependent, and on their family members and society,” said Dr. Janet Woodcock, who directs the FDA's Center for Drug Evaluation and Research. “This drug approval represents a significant advancement in addiction treatment.”