A monthly injection to treat opioid dependence, approved in October 2010 by the U.S. Food and Drug Administration (FDA), has gotten off to a slow start but is proving useful in helping certain patients, say doctors familiar with the drug, extended-release naltrexone (Vivitrol).

The approval of Vivitrol gives substance abuse treatment providers an alternative to daily methadone or buprenorphine, which has been the standard of care for addiction to heroin or prescription pain medications. Both drugs suppress withdrawal and cravings, but many patients find it difficult to stick with daily treatment, and missing doses of those medications can lead patients to relapse. And because buprenorphine is taken at home, it can be diverted to street sales.

Vivitrol, initially approved by the FDA in 2006 for treating alcohol dependence, is known as an opiate antagonist, meaning it blocks the effects of opiates by occupying the opiate receptor sites in the brain. In contrast, methadone and buprenorphine are agonists, which work by mimicking opiates in the brain. 

Extended-release naltrexone is a major advance over oral naltrexone to treat substance abuse, says Herbert Kleber, MD, Professor of Psychiatry and Director of the Division on Substance Abuse at the Columbia University College of Physicians and Surgeons and the New York State Psychiatric Institute. “My patients say that every time they hold that tablet in their hand, they get a craving–they know if they don’t take it that day, they can get high. You don’t totally remove that feeling with Vivitrol, but at least you’re pushing it down the road for a month.”

Dr. Kleber suggests there are a number of potential candidates for Vivitrol, including those who have been addicted to opioids for a year or less. “Patients who have been addicted for more than a year may find that Vivitrol is not enough for them. Their brain has changed, and they may need an agonist,” Dr. Kleber noted. Vivitrol also can be used for people who are incarcerated, he says. “The criminal justice system doesn’t like agonist therapy, because they see it as replacing one narcotic for another. My hope is that they may be more inclined to use Vivitrol for probationers or those leaving prison as they transition to the outside world.”

Professionals who are in treatment for substance abuse, such as pilots or physicians, may also find Vivitrol an appealing option if their treatment must be supervised, since it does not require daily medication. Other possible candidates include patients coming off methadone or buprenorphine. They are at high risk for relapse during those first critical few months. Although they have to be off those maintenance drugs for anywhere from a week to 10 days to avoid precipitated withdrawal.

He tells patients that if they choose buprenorphine, they may be on it for years and it’s not that easy to get off it. How long an individual stays on Vivitrol varies, he says. “For someone who has some things going for them, like education, job skills or interpersonal skills, then I think six months might be a good number to shoot for. It’s between the three months the patient wants and the one year that I would like.”

Vivitrol should be used along with some type of counseling, Dr. Kleber says. “If you don’t use counseling, it can be difficult to get a person to come back for the next shot,” he says. “Vivitrol promotes abstinence, but that is not the same as recovery.”

Sales of extended-release naltrexone have been slower than expected, notes Ivan Montoya, MD, Deputy Director of the Division of Pharmacotherapies and Medical Consequences of Drug Abuse at the National Institute on Drug Abuse (NIDA), who was part of the FDA panel that recommended approval of the medication. “Alkermes, the company that makes Vivitrol, has responded to slow sales by increasing the price, which makes it less accessible,” he says. “There needs to be more education of physicians about the benefits of this medication and why patients need to be motivated to detoxify in order to use it.”

Cost is a Concern

A major issue with Vivitrol is its cost—approximately $1,000 per month. Dr. Kleber has seen the price shoot up to $1,295 for his patients. He notes that for patients with private insurance, Alkermes will reimburse patients for up to $500 for their copay.

“Right now there’s very poor penetration of insurance coverage, but that’s improving,” says Marc Fishman, MD, Medical Director at Maryland Treatment Centers and Assistant Professor of Psychiatry in the Department of Psychiatry and Behavioral Sciences at Johns Hopkins University School of Medicine. “Most of my patients are middle-class or underserved, and if there’s no insurance coverage for Vivitrol, then it’s not an option.” The entire cost for starting Vivitrol is especially high for his patients because he starts them on an inpatient basis. Because patients have to wait about a week after they have detoxed before starting Vivitrol, it’s difficult to administer the first shot on an outpatient basis, Dr. Fishman says. “If they start using again, then they have to restart the seven-day count. We tend to start people on an inpatient basis so I’m assured they’re opioid-free.” If a person takes Vivitrol while they still have opioids, buprenorphine or methadone in their system, it will precipitate withdrawal.

While Vivitrol is expensive, so is the all-too-often seen alternative, says Frank Vocci, PhD, formerly the Director of the Division of Pharmacotherapies and Medical Consequences of Drug Abuse at NIDA. “It can cost $55,000 to house someone in prison, compared with about $12,000 a year for Vivitrol—plus a person taking the monthly injections can still be working, so you’re turning a tax burden into a taxpayer,” says Dr. Vocci, who is now President of Friends Research Institute in Baltimore. “If we could treat people who were addicted to opiates just prior to release from prison with Vivitrol, that drug-free month might enable them to stay off opiates long enough to get their life back together rather than getting right back into the criminal lifestyle.”

Treating Younger Patients

Dr. Fishman says that although Vivitrol is approved for people ages 18 and older, it can be very useful for certain younger patients as well. “Youth opioid dependence is an exploding problem,” he says. “We haven’t thought of addiction medications as having a place for young people. The standard of care has been detox followed by psychosocial interventions, but adherence rates have been abysmally low. The standard of care ought to transition youth with opioid dependence to a full and comprehensive treatment program that includes medical monitoring and a strong consideration of relapse prevention medication.”

Because the methadone delivery system isn’t “youth friendly,” Dr. Fishman says young people with opioid dependence should be offered either buprenorphine or extended-release naltrexone. While some adults with opioid dependence prefer buprenorphine because they enjoy feeling some opioid effect, teens often don’t need that opioid reinforcement, he says. He notes that even though a monthly injection is easier than daily treatment in terms of adherence, teens still need their families’ help in making sure they keep appointments and keeping track of insurance benefits and copays, he adds.

Beyond Opioid Treatment

Vivitrol may one day be used for other types of dependence. At the recent American Society of Addiction Medicine annual meeting, researchers presented data about extended-release naltrexone for nicotine dependence, as well as amphetamine and methamphetamine dependence. “The preliminary results were very encouraging,” NIDA’s Dr. Montoya says. “It’s a medication that’s gaining a lot of momentum.  Hopefully it will open up more therapeutic possibilities.”