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Opioid Use Disorder


Opioid addiction has been a major public health challenge for many years. But progress is being made in helping those who are affected by opioid addiction—or, as it is known in the medical world, opioid use disorder (OUD)—to overcome it.

Like other substance use disorders, OUD is a chronic brain disease in which people continue to use opioids in spite of harms caused by their use. In 2019, 1.6 million people in the U.S. were diagnosed with OUD and, in 2018, nearly 50,000 people—around 130 people per day—died from overdoses involving opioids.

What’s more, these statistics don’t include the damage opioid misuse can inflict on people’s everyday lives, not to mention those of the people around them. Misuse of these drugs can disrupt relationships with friends and family, harm performance at work or school, and can result in serious health and legal consequences. Though OUD is a long-term disease, it is treatable. Medications and behavioral therapies can help people with OUD stop using opioids and support them in their recovery.

“Opioid use disorder, like any other chronic disease, may cause significant impairment without effective care. Highly effective treatment is available and not only saves lives, but also improves quality of life," says Jeanette Tetrault, MD, an attending physician at Yale New Haven Hospital (YNHH), who also provides primary care and substance use disorder treatment at the central medical unit of the APT Foundation in New Haven, a multi-specialty addiction treatment facility that is affiliated with YNHH. “By partnering with a provider, individuals can engage in a treatment plan that works for them.”

What are opioids?

Opioids are a class of naturally occurring (opiates) and manufactured chemicals (opioids) that are frequently prescribed to relieve pain. They are typically prescribed following surgery or serious injury, or to manage long-term pain caused by cancer and other conditions. Sometimes they are used as cough suppressants or to alleviate diarrhea.

Morphine and codeine are examples of naturally occurring opioids. Manufactured opioids include oxycodone, hydrocodone, fentanyl, and methadone, among many others. While these opioids are all available by prescription, illicit opioids, like heroin (and, increasingly, illicitly manufactured fentanyl), are not.

How do opioids work?

When opioids enter the body, they interact with opioid receptors in the brain, producing a number of physiological responses, including pain relief. But they also stimulate the reward pathway in the brain, which can cause a feeling of well-being and happiness known as euphoria.  

This activation of the reward pathway makes opioids addictive for some people. Continued use of the drugs causes changes in the brain that lead to tolerance. This means that a larger dose of opioids is needed to get the same level of pain relief or euphoric high.

Over time, people who use opioids (for pain or other reasons) develop a physical dependence on the drug, meaning that if they stop taking opioids, they experience withdrawal symptoms. At that point, some may take opioids to put an end to withdrawal symptoms rather than to achieve pain relief or a high. Importantly, physical dependence with tolerance and withdrawal alone do not mean someone has an opioid use disorder.

What is opioid use disorder?

Opioid use disorder is a chronic disease of the brain—sometimes called an addiction—characterized by the persistent use of opioids despite harmful consequences caused by their use. Patients typically have both physical dependence and loss of control over their opioid use and may experience serious consequences related to their use. It is a relapsing disorder, which means that if people who have OUD stop using opioids, they are at increased risk of reverting to opioid use, even after years of abstinence.

A diagnosis of OUD is made when a person who regularly uses opioids has experienced at least two of the following signs and symptoms within the past 12-month period:

  • Physical dependence:
    • Developing tolerance to opioids, meaning that larger quantities are required to attain the desired effect of the drug
    • Experiencing withdrawal symptoms if stopping opioid use, or using opioids to alleviate symptoms of withdrawal
  • Loss of control:
    • Taking opioids in greater quantities or for longer than planned
    • Inability to quit or reduce use of opioids despite wanting to do so
    • Devoting a lot of time to acquiring, using, or recovering from opioids
    • Feeling compelled to use opioids
  • Consequences:
    • Opioid use repeatedly interferes with completing duties at home, work, or school
    • Continuing use of opioids even when they cause problems interacting with others
    • Skipping important occasions and events at work, school, or in personal life
    • Repeatedly taking opioids in circumstances that could cause physical harm (e.g., while operating a motor vehicle)
    • Continuing use of opioids even when they cause or exacerbate mental or physical problems

The more of the above symptoms individuals experience, the greater the severity of their OUD:

  • Mild: 2–3 symptoms present
  • Moderate: 4–5 symptoms present
  • Severe: 6 or more symptoms present

Note that if someone is prescribed opioids for pain and is using them as prescribed, the physical dependence criteria are not factored into the number of signs and symptoms.

Not everyone who uses opioids develops OUD, though some do. Even people who use opioids only as prescribed by a physician can develop OUD. Over time, they may begin to misuse opioids, taking them for reasons other than for which they were originally prescribed. 

They may try to obtain prescriptions from a doctor, but because there may be difficulty obtaining a prescription for opioids, they may also try to get them from friends or family members, or in some cases, they may turn to illicit, injectable (and cheaper) opioids like heroin or fentanyl. 

What are the health risks associated with opioid use disorder?

The use of opioids raises the risk of injury or death from accidents, while the use of injectable opioids increases risk for bloodborne infectious diseases including HIV, hepatitis B, hepatitis C, and bacterial endocarditis, a potentially dangerous infection of the inner lining of the heart and its valves.

Overdose is a significant risk of opioid use. In addition to relieving pain and producing euphoria, opioids stimulate a range of other physiological responses. For example, taking a large dose of opioids can slow or even stop breathing, which can lead to death.

Opioids can cause constipation and nausea and can suppress the immune system. They can also increase or decrease the levels of various hormones, which can lead to reduced libido and, in women, infrequent or even entirely absent menstruation.

What are the risk factors for opioid use disorder?

A number of factors are associated with an increased risk for OUD:

  • Access to and availability of opioids
  • Previous exposure to substance use (e.g., having friends or family who use substances)
  • Current or past substance use disorder
  • Family history of substance use disorder
  • Having mental health conditions such as depression or post-traumatic stress disorder
  • History of abuse during childhood
  • History of conduct disorder as a child or adolescent

What is medically managed withdrawal or "detoxification"?

Detoxification refers to the elimination of drugs from the body. When this takes place under medical supervision, it is termed "medically managed withdrawal."

Many people who have OUD want to control their addiction. Some of them may try to abruptly discontinue their use of opioids on their own, without medical assistance. This sudden elimination of opioids from the body brings on a cluster of unpleasant withdrawal symptoms that can include nausea, diarrhea, sweating, anxiety, muscle and joint pain, and runny nose, among others. 

These symptoms can occur within hours of their last use and can last for days to weeks. But stopping “cold turkey” is so uncomfortable and triggers powerful cravings for opioids that, in most cases, it results in relapse to opioid use to relieve the withdrawal symptoms.

Another detoxification option, known as medically managed withdrawal, has greater likelihood of success. In medically managed withdrawal, people with OUD stop using opioids, but rather than trying to deal with withdrawal symptoms on their own, doctors provide them with medications, including tapering doses of opioids, that decreases withdrawal symptoms.

Since OUD is a chronic disease, medically managed withdrawal is like treating a heart attack without treating the patient’s underlying heart disease that caused the heart attack. It’s important to realize that people who stop using opioids, whether through a medically managed detoxification or on one’s own, frequently relapse and are at increased risk of overdose since they have lost their physical tolerance to opioids.

Because of this, doctors recommend that after medically managed withdrawal, people who have OUD continue long-term treatment to avert and/or address relapse to opioid use.

How is opioid use disorder treated?

The most effective treatments for opioid use disorder include the combined use of medication and behavioral treatment. These treatments are routinely provided on an outpatient basis, including primary care or at federally regulated opioid treatment programs. They can also be provided at a part- or full-time residential facility that specializes in treating substance use disorders.

Medications. The Food and Drug Administration (FDA) has approved three medications—methadone, buprenorphine, and naltrexone—for the treatment of OUD.

  • Methadone. This medication blocks the effects of other opioids, controls withdrawal symptoms, and reduces cravings for opioids. Because methadone is itself an opioid with the potential for misuse and dependence, it can only be obtained at specially licensed treatment facilities. 
  • Buprenorphine. Like methadone, this medication is an opioid, used to block the effect of other opioids, lessen withdrawal symptoms, and reduce cravings. But unlike methadone, it can be prescribed by physicians and advanced practice providers (including primary care) and obtained at a pharmacy. Buprenorphine is usually provided in combination with naloxone.
  • Naltrexone. This medication, which is not an opioid, works by blocking opioids from binding to certain receptors in the brain. This means that if someone taking naltrexone also takes an opioid, the opioid will not produce the desired effects, including feelings of euphoria, and that person is less likely to continue opioid use or to relapse. Naltrexone is often given as a long-lasting injectable that works for four weeks.

While methadone and buprenorphine can produce feelings of euphoria in people who do not otherwise take opioids, they do not cause euphoric effects in people with OUD, who have developed a tolerance to opioids. The treatment doses of methadone and buprenorphine are sufficient for blocking the effects of other opioids, reducing cravings, and suppressing withdrawal symptoms, but not enough to generate the euphoric high.

People with OUD may continue treatment with these medications for years and even decades.

Counseling and behavioral therapy. These aim to help people with OUD learn new ways of thinking about and relating to drug use and can also encourage them to adhere to treatment regimens.

This type of therapy encompasses several approaches, which may be offered in person or via telehealth and sometimes in combination, including:

  • Medication management. A brief, medically focused counseling similar to what is provided to patients with depression. The sessions cover recent drug use or efforts to achieve or maintain abstinence, attendance in mutual-help groups, support for efforts to reduce drug use or remain abstinent, advice for the achievement or maintenance of abstinence, and the results of urine drug tests. In addition, the prescriber assesses employment, legal, family, or social, medical, and psychiatric progress related to addiction
  • Cognitive-behavioral therapy (CBT). Aims to help people recognize and reframe negative modes of thought that may play a role in enabling their opioid use and disruptive behavior
  • Contingency management. Reinforces certain behaviors, by offering patients material rewards for meeting behavioral goals, such as abstinence from opioids. For example, an individual might be given a voucher as a reward for testing negative on a urine drug test or for maintaining regular attendance at counseling and therapy sessions
  • Motivational enhancement therapy. Gives people ways to address their mixed feelings about opioid use and helps foster motivation and commitment to addressing their OUD
  • Family counseling. Aims to help people with OUD and their families understand and cope with the disease and the social and other harms it can cause 
  • Mutual help groups. These include programs such as SMART (Self-Management and Recovery Training) Recovery, Narcotics Anonymous, Methadone Anonymous, and others, including Alcoholics Anonymous, in which participants help and mentor one another in their recovery from OUD
  • Harm reduction education. Because ongoing use or relapse are common and not all individuals are able to engage in formal treatment, care of patients with OUD often involves an educational component designed to minimize the harm associated with their opioid use. This is like the education that patients with heart disease or diabetes receive if they are not meeting their target goals of treatment. Patients, family, and partners may be taught about naloxone to reverse opioid overdose, safe use of syringes to reduce the risk of acquiring an infectious disease through opioid injection, or about the risks of mixing certain drugs with opioids.

How does opioid use disorder affect pregnant women and newborns?

Opioid use during pregnancy affects both mother and baby. For instance, babies born to mothers who have OUD may have opioid dependence and can experience withdrawal symptoms. This condition is called neonatal opioid withdrawal syndrome (NOWS). NOWS can cause early labor, fetal growth restriction, placental abruption, and fetal death among other problems.

Because of this, pregnant women who have OUD have the best outcomes for themselves and their newborns if they are receiving medical treatment. Methadone and buprenorphine are safe to use while pregnant and breastfeeding and can improve outcomes for both mother and baby.

What is the outlook for people who have opioid use disorder?

Because OUD is a chronic brain disease, relapses can occur. People with untreated OUD often experience social, legal, economic, and health consequences as a result of their opioid use. What’s more, people who have OUD may face social stigmatization. It is important to remember that OUD is not the result of personal failure or insufficient willpower; it is a brain disease for which effective treatment options are available.

Medications can block the effect of opioids, as well as control withdrawal and craving, and behavioral therapy and counseling can help people learn to cope with and relate to opioids in healthy ways. People who are in treatment for their OUD are often able to improve many aspects of their social functioning and health.

What makes Yale Medicine’s approach to opioid use disorder unique?

Yale Medicine has been a pioneer in the treatment of opioid use disorder in routine clinical settings. This goal of making sure there is “no wrong door” for patients and families includes providing treatment for OUD in primary care, Ob/Gyn offices, infectious disease clinics, and initiating treatment in places like the hospital and the emergency department.

“This model not only makes effective treatment more accessible, it helps to address the stigma patients and families may feel by allowing them to receive care in a general medical setting,” says Gail D’Onofrio, MD, MS, professor and chair of emergency medicine at Yale Medicine.

Written by Jeremy Ledger. Last medically reviewed by Jeanette Tetrault, MD, and Gail D’Onofrio, MD, MS, in December 2020.



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