Oct. 14, 2010 -- The FDA has approved a drug already used to treat alcohol dependence to help treat patients with addiction to heroin, morphine, and other opioids, including prescription painkillers such as OxyContin and Vicodin.

Vivitrol, a long-acting formulation of naltrexone given by injection once a month, was approved by the FDA to treat alcohol dependence in 2006. The FDA has now approved Vivitrol to treat and prevent relapse after patients with opioid addiction have undergone detoxification.

Vivitrol is in the class of drugs known as opioid antagonists, which block the brain’s opioid receptors, leaving patients unable to get high if they attempt to use opioids.

The FDA approved the use of Vivitrol on the basis of data from a six-month study that compared Vivitrol to placebo treatment in patients who had completed detoxification and who were no longer physically dependent on opioids.

The FDA says in a news release that patients treated with Vivitrol were more likely to stay in treatment and refrain from using illicit drugs. The agency says 36% of the Vivitrol-treated patients were able to stay in treatment for the full six months without using drugs, compared with 23% in the placebo group.
Vivitrol Side Effects

Vivitrol should be administered by a doctor as an intramuscular injection, using special needles provided with the medication, the FDA says. Also, Vivitrol should not be injected using any other needle.

The FDA warns that side effects include nausea, tiredness, headache, dizziness, vomiting, decreased appetite, painful joints, and muscle cramps.

Other possible side effects are reactions at the injection site that could require surgical treatment, liver damage, pneumonia, depressed mood, suicide, suicidal thoughts, suicidal behavior, and allergic reactions such as rashes, hives, and swelling of the face.

Patients must not have any opioids in their system when they start taking Vivitrol because they would risk withdrawal symptoms. The FDA also says patients may be more sensitive to opioids while taking Vivitrol and that overdose could result if patients restart opioid use after missing an injection.
Addiction in the U.S.

“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,” Janet Woodcock, MD, director of the FDA’s Center for Drug Evaluation and research, says in a news release. “This drug approval represents a significant advancement in addiction treatment.”

Nora D. Volkow, MD, director of the National Institute on Drug Abuse (NIDA), says heroin addiction afflicts about 810,000 people in the U.S., most of whom neither seek nor receive treatment. In 2008, she says 1.85 million people in the U.S. met the diagnostic criteria for abuse or dependence on opioid pain relievers such as OxyContin and Vicodin.

“Vivitrol is the first non-narcotic, non-addictive extended release medication approved for the treatment of opioid dependence, marking an important turning point in our approach to treatment,” Volkow says in a statement issued by NIDA.