What Drugs Are Used To Treat Opioid Addiction?

Opioid addiction is one of the biggest public health problems currently facing the United States, with nearly 400,000 people dying as a result of opioid overdose during 1999–2017.1

Assured by pharmaceutical companies in the late 1990s that patients wouldn’t become addicted to opioid pain relievers, healthcare providers increased the number of prescriptions for prescription pain relievers, which led to widespread misuse of opioids. As overdose deaths skyrocketed, it started to become clear just how highly addictive and dangerous these medications are.2

Approximately 21–29% of patients prescribed opioids for chronic pain misuse them, with between 8 and 12% developing an opioid use disorder.3 According to the 2018 National Survey on Drug Use and Health, more than 2 million Americans struggle with an opioid use disorder.4

Fortunately, there are several effective drugs and treatment strategies that are used to treat opioid addiction, giving people an opportunity to turn their lives around and enjoy fulfilling and long-term recovery.

The Mechanism of Opioid Use

Opiates like heroin and morphine are derived from the opium in the poppy plant. Synthetic (e.g., fentanyl) and semi-synthetic opioids (e.g., hydrocodone, oxycodone and others) are produced in laboratories. Whether the opioids are legal, like prescription painkillers, or illegal, like heroin or diverted fentanyl, the chemicals and mechanisms of action are the same or, at least, very similar.5

Opioids attach to specific receptors in the brain. Different opioids have different effects on the receptors, but the most potent opioids—like heroin, fentanyl, and prescription painkillers—produce an intensely overwhelming calming effect while at the same interrupting the body’s natural pain pathways.5,6

As pain signals are blocked, opioids also release large amounts of dopamine throughout the body.6 Dopamine is integral to our body’s reward system; it affects our mood and motivation as well as helps to regulate our emotional responses.5,6

By stimulating the body’s reward circuit into associating the intake of the drug with feelings of pleasure and reduced pain, users are compelled to repeat the behavior of drug administration, often without thinking of the negative consequences.5,7

How Do Opioid Treatment Drugs Work?

The American Society for Addiction Medicine (ASAM) describes addiction as a chronic, treatable medical disease that involves “complex interactions among brain circuits, genetics, the environment and an individual’s life experiences.”8

Acknowledging this, the Substance Abuse and Mental Health Services Administration (SAMHSA) and ASAM both recommend evidence-based patient-centered care consisting of medication that’s been proven to be effective supplemented with necessary mental health services, addiction counseling and recovery support services.9,10

There are three FDA-approved medications for treating opioid use disorder: methadone, buprenorphine, and naltrexone.9

Each of these drugs interact with the body’s opioid receptors in different ways:

  • Methadone is an opioid agonist that binds to the same receptors as other opioid drugs; however, it does so more slowly and will not produce euphoria in someone who is dependent on opioids.11 Methadone can effectively help to reduce or eliminate withdrawal symptoms and cravings to use opioids.9
  • Buprenorphine is a partial opioid agonist that binds to opioid receptors but activates them less strongly than a full agonist.11 It has a ceiling effect that limits feelings of euphoria but is still effective in reducing cravings and reducing the severity of withdrawal symptoms.9,11
  • Naltrexone is an opioid antagonist that works by blocking the activation of opioid receptors.11 This prevents the ability for an opioid to produce a high, but unlike methadone and buprenorphine, it also doesn’t help to control withdrawal or cravings to use opioids.9,11

Although it may seem counterproductive for someone addicted to an opioid to take another opioid-based medication, studies show that individuals with an opioid use disorder who undergo medical detoxification followed by complete abstinence are very likely to relapse or return to using opioids.11

Methadone, buprenorphine, and naltrexone have all been shown to increase the likelihood a person will remain in treatment, which in turn lowers risk of overdose, reduces risk of bloodborne disease such as HIV, and improves the likelihood of employment.12

Methadone Use and Risks

When it comes to treating an opioid addiction, the traditional first-line of attack is methadone, an opioid agonist that’s been used since 1947 to reduce opioid use in individuals with an opioid use disorder.12

Methadone is recommended for individuals in a supervised treatment environment where daily dosing can be closely monitored.10 Opioid treatment programs are required to monitor methadone administration to avoid misuse or illegal diversion.10

Methadone is not without its risks. As a full agonist, it can induce some of the same side effects as other opioids, and dosage must be carefully monitored by treatment programs to avoid over-sedation or overdose.10

Buprenorphine Use and Risks

As a partial agonist, buprenorphine causes fewer effects traditionally associated with opioids and at a lower intensity.11 The risk of harms, such as a fatal overdose, are significantly lower than those of full agonist opioids (e.g., oxycodone, hydrocodone, heroin, etc.).11

Like methadone, buprenorphine is closely regulated and requires federal approval to dispense. However, buprenorphine doses do not require supervised administration, and many programs and providers have been granted waivers by the federal government, which gives individuals the freedom to self-administer the medication at home.11

As a long acting opioid with a high affinity for the body’s opioid receptors, buprenorphine interferes with the effects of full opioid agonists, such as heroin, by blocking their ability to bond with opioid receptors.13 Diversion of buprenorphine does occur, but it’s unlikely someone who has developed a dependence to full opioid agonists would choose to switch to buprenorphine in an effort to get or maintain a high. In fact, survey data shows that illicit buprenorphine use is often used to reduce withdrawal symptoms as well as reduce illicit heroin use.13

Buprenorphine is sometimes combined with naloxone in a film that’s administered by dissolving it under the tongue. The naloxone has no effect when administered via this route, but should a person dissolve the film in water and try to inject it intravenously, the naloxone—an opioid antagonist—is activated and begins reversing the effects of any opioids in the system, which then precipitates withdrawal symptoms.13

Buprenorphine is also available as a 6-month subdermal implant and a once-monthly injection that eliminates the need for daily dosing.11

Additional Considerations

The use of naltrexone, which blocks the activation of opioid receptors, is typically not used during opioid withdrawal as it does not help to lessen the severity of withdrawal symptoms or reduce cravings to use opioids.9,10 Naltrexone’s typically used to prevent relapse but only after complete detoxification.14

Despite some risks, long-term buprenorphine or methadone treatment is considered a critical part of successful opioid addiction treatment, and both medications have been proven to be safe and effective when combined with psychosocial treatment such as individual and group therapy, addiction counseling and referrals to mutual-help groups and other community services.10


  1. Scholl, L., Seth, P., Kariisa, M., Wilson, N., & Baldwin, G. (2018). Drug and Opioid-Involved Overdose Deaths – United States, 2013-2017Morbidity and Mortality Weekly Report, 67(5152), 1419–1427.
  2. Department of Health and Human Services. (2019). What is the U.S. Opioid Epidemic?
  3. National Institute on Drug Abuse. (2019). Opioid Overdose Crisis.
  4. Center for Behavioral Health Statistics and Quality. (2019). Results from the 2018 National Survey on Drug Use and Health: Detailed Tables. Substance Abuse and Mental Health Services Administration, Rockville, MD.
  5. National Institute on Drug Abuse. (2019). Drug Facts: Prescription Opioids: What are prescription opioids?
  6. National Institute on Drug Abuse. (2019). The Neurobiology of Drug Addiction.
  7. National Institute on Drug Abuse. (2019). The Neurobiology of Drug Addiction: Rats self-administer heroin.
  8. American Society of Addiction Medicine. (2019). Definition of Addiction.
  9. Substance Abuse and Mental Health Services Administration. (2018). TIP 63: Medications for Opioid Use Disorder.
  10. American Society of Addiction Medicine. (2015). The ASAM National Practice Guideline for the Use of Medications in the Treatment of Addiction Involving Opioid Use.
  11. National Institute on Drug Abuse. (2018). How do medications to treat opioid use disorder work?
  12. National Institute on Drug Abuse. (2018). How effective are medications to treat opioid use disorder?
  13. National Institute on Drug Abuse. (2018). What is the treatment need versus the diversion risk for opioid use disorder treatment?
  14. National Institute on Drug Abuse. (2016). Effective Treatments for Opioid Addiction.