Naltrexone (Vivitrol) for Opioid Addiction: A Comprehensive Guide

Among the three FDA-approved medications for opioid use disorder, naltrexone — sold under the brand name Vivitrol as an extended-release injection — offers a unique profile: it is completely non-addictive, non-opioid, and works by a completely different mechanism than methadone or buprenorphine. For the right patients, naltrexone can be a highly effective component of opioid addiction recovery.

At Pink Chances Med Corp in Tujunga, CA, our medical team provides comprehensive evaluation to help patients determine which MAT medication — including naltrexone — is best suited to their individual needs and recovery goals.

How Naltrexone Works

Naltrexone is an opioid antagonist — it completely blocks opioid receptors in the brain. Unlike methadone or buprenorphine, which activate opioid receptors (either fully or partially), naltrexone has no opioid agonist activity. This means:

  • Naltrexone itself produces no opioid effects — no euphoria, no sedation
  • If opioids are used while on naltrexone, they produce no effect (the receptors are blocked)
  • There is no risk of physical dependence on naltrexone
  • Naltrexone is not a controlled substance

By removing the rewarding effects of opioids, naltrexone significantly reduces the motivation to use them, and over time, the conditioned associations between opioid use and pleasure begin to weaken.

Naltrexone vs. Vivitrol

Naltrexone is available in two forms:

  • Daily oral tablet (Revia): Requires daily adherence, which can be challenging for some patients
  • Extended-release injection (Vivitrol): Given once monthly by intramuscular injection, eliminating the daily adherence challenge. This is the most commonly used form in opioid addiction treatment.

Who Is Naltrexone Best For?

Naltrexone is particularly well-suited for:

  • Highly motivated patients who have completed detoxification
  • Patients who prefer not to take an opioid-based medication (agonist therapy)
  • Patients in professions where opioid agonist medications may be restricted (pilots, truck drivers, certain law enforcement)
  • Patients who have completed other treatment and want ongoing pharmacological protection against relapse
  • Patients whose primary concern is the craving/reward aspect rather than physical withdrawal

The Critical Requirement: Full Detoxification

The most important requirement for naltrexone treatment is that the patient must be completely opioid-free for 7-10 days (and longer for long-acting opioids or methadone) before starting. Starting naltrexone while opioids are still in the system precipitates immediate, severe withdrawal.

This requirement makes naltrexone unsuitable for patients who cannot first achieve a period of abstinence, or those who find the prospect of a full detoxification period unmanageable. For these patients, buprenorphine or methadone is often a more appropriate starting point.

The Evidence for Naltrexone Effectiveness

Clinical trials, including the landmark X:BOT study published in the Lancet, showed that extended-release naltrexone (Vivitrol) is as effective as buprenorphine-naloxone in preventing relapse among patients who successfully complete detoxification. The key qualifier is successful completion of detox — fewer patients in the naltrexone arm completed detox and initiated treatment compared to buprenorphine patients.

Naltrexone in a Comprehensive Treatment Program

Like all MAT medications, naltrexone is most effective when combined with comprehensive behavioral health services. At Pink Chances, naltrexone patients participate in:

Frequently Asked Questions About Naltrexone

Will I feel sick if I take naltrexone?

As long as you have fully detoxed before starting, naltrexone should not make you feel sick. Common mild side effects include nausea (especially in the first week), headache, and fatigue, which typically resolve quickly.

What happens if I use opioids while on naltrexone?

The opioids will produce little to no effect because receptors are blocked. However, some patients attempt to overcome the blockade with very large doses of opioids, which is extremely dangerous and can cause fatal overdose when the naltrexone eventually wears off.

Is naltrexone covered by insurance?

Yes. Most insurance plans, including Medi-Cal and Medicare, cover naltrexone. Vivitrol also has patient assistance programs for those without adequate insurance coverage.

Explore Your MAT Options at Pink Chances

Naltrexone is one of three proven MAT options available at Pink Chances Med Corp in Tujunga. Our medical team will help you determine which medication — Methadone, Suboxone, or Naltrexone — is best for your recovery journey. Call (888) 821-PINK or contact us today. Serving Los Angeles, Glendale, Burbank, North Hollywood, and the San Fernando Valley.