The havoc wrought by the opioid epidemic is widely known. Statistics attest the depth and dimension of this drug crisis. For example, an estimated 130 people die from opioid-related drug overdoses every day, and about 2.1 million have an opioid use disorder. Plus, overdoses have surpassed car crashes and gun violence to become the leading cause of death for Americans under the age of 55.

What’s more, highly potent and lethal synthetic opioids like fentanyl are fueling the latest wave of this crisis, claiming thousands of lives in its wake. 

What isn’t talked about enough is the reason opioids ensnare so many people regardless of their socioeconomic standing, ethnicity, politics, or geographic location. As one user told The New York Times for a 2018 story on heroin addiction, “It’s like being hugged by Jesus.” She was referring to a heroin high.

The pervasiveness of this epidemic has brought opioid blockers, that is, medications capable of blocking the profound effects of opioids, to the fore.

Currently, the best options for opioid blockers are naloxone (Narcan, Evzio) and naltrexone (Revia, Vivitrol). Both types are utilized in reputable drug treatment programs as part of medication-assisted treatment (MAT), an approach that has been proven to break the grips of addiction.

Read on to learn more about opioid blockers and how they are administered in opioid treatment.

What Are Opioid Blockers?

Every compelling story ever written has an antagonist, a person or element that is hostile to someone or something. In literature, the antagonist is usually the hero’s adversary. In real life, opioids, especially cast as a substance of abuse, are anything but heroic. Opioid blockers or antagonists like naloxone and naltrexone work to block the effects of opioids and can help reverse addiction.


Naltrexone has been in use for about 30 years. As a synthetic opioid antagonist, naltrexone blocks opioids from binding to receptors, which prevents users from experiencing their euphoric effects.

Naltrexone is sold under the brand names of Vivitrol, Revia, and Depade, and it treats fibromyalgia, hair pulling disorder, and smoking cessation, in addition to alcohol and opioid dependence. Naltrexone multi-ingredient medications that contain bupropion treat obesity and weight loss. Naltrexone medications that contain either oxycodone or morphine are prescribed to address pain.


Naloxone, by itself, is a medication formulated to quickly reverse an opioid overdose. As an opioid antagonist, it works by binding to opioid receptors in the brain to reverse or block the effects of other opioids. Opioid overdose, either from heroin or prescription medications, typically results in respiratory depression. When administered, naloxone can rapidly restore normal respiration to someone whose breathing has slowed or stopped.

Naloxone, as an overdose antidote, is sold under the brand names of Evzio and Narcan. It is also included in multi-ingredient medications such as Suboxone, Bunavail, Zubsolv, and Cassipa, which are used to treat opiate dependence. It is also combined with oxycodone and pentazocine in prescription medications to treat pain.

Naltrexone vs. Naloxone: What’s The Difference?

The difference between these two opioid blockers lies in how they are typically administered. As a short-term opioid blocker, naloxone is mainly employed as a rescue medication, usually via injection or nasal spray, when someone is experiencing an opioid overdose.

Naltrexone, which is available as an extended-release oral medication (Vivitrol and NTX), slowly releases into the body, which makes it an ideal blocker as a post-recovery, after detox treatment. It is used to help prevent opioid dependency during recovery and has value in that it can help users avoid relapse.  

Naloxone acts within minutes and lasts for about an hour thanks to its rapid metabolism.  Naltrexone acts slowly and lasts a lot longer. Naloxone treats overdoses, but naltrexone cannot. Naltrexone blocks alcohol and opioid cravings, while naloxone alone cannot.

Professional Addiction Treatment and Opioid Blockers

MAT or medication-assisted treatment is the use of approved medications to treat drug and alcohol addictions, particularly opioids, whether they are of the illicit variety like heroin or the prescription kind like oxycodone.

These medicines work by alleviating withdrawal symptoms and cravings that occur with addiction. Medicines used to treat an overdose, like naloxone, also fall under the MAT designation.

Because opioids spark a surge of dopamine, the chemical that compels people to keep taking them, the brain is profoundly changed or rewired. A user will become accustomed to the presence of the drug in their system, developing a tolerance and becoming opioid dependent in the process.

“MAT drugs work to reverse that rewiring by normalizing a user’s brain chemistry without subjecting them to the euphoric feelings that come from opioids nor the painful, flu-like symptoms that result from opioid withdrawal.  ”

Naloxone is formulated with buprenorphine to form Suboxone, which is used to treat opioid dependence. Suboxone also contains buprenorphine, a partial agonist. This means it can partially produce the effects of opioids. What results are sensations far weaker than full agonist opioids — the heroin, OxyContin, and Vicodin of the world.  

When Opioid Blockers Are Used in Treatment

Under the scope of professional addiction treatment, which consists of  medical detoxification via acute treatment, clinical stabilization services, and outpatient care, the MAT medication Suboxone is administered during the detox process to treat withdrawal.

Naltrexone is typically prescribed in outpatient settings as a long-term, maintenance medication for people in recovery, much like methadone. It is also administered at the clinical stabilization stage, after detox, in combination with therapy and counseling.

MAT drugs, in combination with cognitive behavioral therapy and counseling, have proven to be effective in treating opioid addictions. 

How Professional Treatment Can Help You

The goal of professional treatment is to address the ravages of addiction by treating your mind, body, and soul. A reputable rehab program will remove the opioids from your body, help you achieve mental and physical stabilization, assist by getting you to understand the underlying causes of your addiction, and equip you with effective strategies to avoid relapse.

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