Is Vivitrol as effective as Suboxone?

By November 19, 2017addiction science
Vivitrol blocking opiate molecules.

Opiate abuse and addiction is the fastest growing substance use problem in the United States, and treatment for opiate addiction requires long-term management. Behavioral interventions alone have poor outcomes, with upwards of 80% of patients returning to drug use. But the rates are substantially raised with long-term monitoring programs and medication-assisted treatment (1).

Medication-assisted treatment is a treatment for addiction that includes the use of medication along with counseling, 12-step programs or other support. According to the U.S. Department of Health and Human Services, a treatment that includes medication is often the best choice for opioid addiction (2). Two such medications used for opioid addiction are Vivitrol (naltrexone) and Suboxone. Vivitrol and Suboxone work in similar ways: they block the euphoric effects of opioids which deters drug use (3).

Vivitrol (naltrexone) injection.

As you can see in the illustration above, molecules of Vivitrol  block opioids, preventing their interaction with receptors in the brain. Even if a user takes a drug such as heroin, the user is unable to get a high as Vivitrol blocks the drug interactions. Normally, the opioid molecule would interact with these receptors in the brain, stimulating a euphoric effect that positively reinforces using the drug again.

So what is the difference between Vivitrol (naltrexone) and Suboxone? Suboxone and Vivitrol are each FDA approved for the long-term treatment of opiate addiction. Suboxone is often administered daily as sublingual strips (thin films put into your mouth like a Listerine strip).  Suboxone is an opioid in an of itself and produces a mild euphoric effect.  However, that effect is supposed to plateau at higher doses and thus cannot be abused in the same way.  This can create a dependency on Suboxone, using it as a maintenance drug rather than a short transition. Like heroin, Suboxone results in unpleasant physical and psychological symptoms of withdrawals, creating a negative reinforcement to stay on Suboxone or return to another opiate (1).

Clinician holding up two strips of Suboxone

Clinician holding up two strips of Suboxone.

Vivitrol, first developed in the 1960’s, however, can be administered as a monthly shot, making it impossible to come off of the medication on a whim. A recent study sponsored by the NIDA, the National Institute on Drug Abuse, found that a monthly shot of Vivitrol is as effective as a daily dose of Suboxone (4). Unlike Suboxone, Vivitrol has no intrinsic opiate activity (giving off a euphoric effect), so it poses minimal risk of abuse or diversion into the black market. Vivitrol neither has a positive reinforcement (acting on the same opiate receptors such as with Suboxone) nor a withdrawal effect. Unlike Suboxone, a patient doesn’t become chemically dependent on Vivitrol.

What is the difference between a partial agonist and an antagonist?

The molecules in Suboxone and Vivitrol compete with opioids at receptor sites, each having a high affinity for the type of receptors with which opioids interact. Suboxone is classified as a partial agonist. This means that it acts as an opiate molecule, attaching to receptor sites with high affinity. However, as an agonist, it still creates a partial opiate effect at binding to the site. Heroin, Oxycodone, and others are considered full agonists. This partial effect creates the same, albeit mild, euphoric effect associated with opiate use. Because Suboxone has this partial euphoric effect, it also contains naloxone, what is used in Narcan shots for opiate overdose. This is a deterrent for any misuse of the product.  Unlike Suboxone, Vivitrol is an antagonist, not an agonist, and blocks opiate molecules from binding to receptor sites without creating the euphoric opiate effect in and of itself. 

What are your thoughts on medically-assisted treatment for opiate addiction?

To learn more about Ken Seeley Communities long-term monitoring programs and the potential of medically-assisted treatment for your loved one, call 1-888-800-4911.

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3411273/
  2. https://store.samhsa.gov/shin/content/SMA09-4442/SMA09-4442.pdf
  3. https://archives.drugabuse.gov/meetings/Naltrexone.html
  4. https://www.pbs.org/newshour/health/long-awaited-study-finds-monthly-vivitrol-as-effective-as-daily-pill-for-opioid-addiction