Opioid Use Disorder

Opioid Use Disorder is a substance use disorder characterized by a problematic pattern of opioid use leading to clinically significant impairment or distress. Like with all substance use disorders, there is a complex interplay between biological, social, psychological, and cultural factors.

Opioids are a class of substances that bind to the opioid receptors, including Mu1 (μ1), Mu2 (μ2), Delta (δ), Kappa (κ). It is commonly used as an analgesic to treat pain, but is frequently a substance of abuse. Common opioids include morphine, codeine, hydromorphone, methadone, and drugs of abuse like heroin.

See main article: Opioid Classification

Common side effects of opioids include constipation,[1] sedation, respiratory depression, dizziness, nausea, and vomiting. Physical dependence and addiction are possible serious consequences as well.

The DSM-5 diagnostic criteria for opioid use disorder is as follows:

Criterion A
  1. Opioids are often taken in larger amounts or over a longer period than was intended.
  2. There is a persistent desire or unsuccessful efforts to cut down or control opioid use.
  3. A great deal of time is spent in activities necessary to obtain the opioid, use the opioid, or recover from its effects.
  4. Craving, or a strong desire or urge to use opioids.
  5. Recurrent opioid use resulting in a failure to fulfill major role obligations at work, school, or home.
  6. Continued opioid use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of opioids.
  7. Important social, occupational, or recreational activities are given up or reduced because of opioid use.
  8. Recurrent opioid use in situations in which it is physically hazardous.
  9. Continued opioid use despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by the substance.
  10. Tolerance, as defined by either of the following: (A) a need for markedly increased amounts of opioids to achieve intoxication or desired effect, or (B) a markedly diminished effect with continued use of the same amount of an opioid.
    Note: This criterion is not considered to be met for those taking opioids solely under appropriate medical supervision
  11. Withdrawal, as manifested by either of the following: (A) the characteristic opioid withdrawal syndrome (refer to Criteria A and B of the criteria set for opioid withdrawal), OR, (B) opioids (or a closely related substance) are taken to relieve or avoid withdrawal symptoms.
Note: This criterion is not considered to be met for those taking opioids solely under appropriate medical supervision.


Specify if:

  • In early remission: None of the criteria have been met for > 3 months but < 12 months (exception is Criterion A4).
  • In sustained remission: None of the criteria have been met for 12 months or longer (exception is Criterion A4).
  • On maintenance therapy: This additional specifier is used if the individual is taking a prescribed agonist medication such as methadone or buprenorphine and none of the criteria for opioid use disorder have been met.
  • In a controlled environment: This additional specifier is used if the individual is in an environment where access to opioids is restricted.

Don't forget about decreased tolerance if a patient has not been on opioids for a while! If restarting opioids, start again at a lower dose then taper up.

Opioid withdrawal can often be extremely uncomfortable, but withdrawal by itself is not fatal. However, there are many associated complications that can be fatal such as suicide, accidental overdose (if opioids are taken after a period of abstinence and the individual loses tolerance), exacerbation of respiratory issues, and psychiatric comorbidity. Withdrawal symptoms typically appear at 72 hours after last use. Common symptoms includes tachycardia, sweating, mydriasis (pupil dilation), myalgia, rhinorrhea, piloerection, GI symptoms (nausea, vomiting, stomach cramps, diarrhea), low mood/anxiety, tremors, and intense cravings.

Clinical Opioid Withdrawal Scale (COWS)

The Clinical Opioid Withdrawal Scale (COWS) is a clinical tool used to monitor withdrawal symptoms, and also to determine when to start Suboxone induction. It includes clinical measures assessed by the physician and not subject to patient reporting such as: pulse rate, pupil size, tremors, and yawning.

Scales for Opioid Withdrawal

Name Rater Description Download
Clinical Opioid Withdrawal Scale (COWS) Clinician An 11-item scale designed to be administered by a clinician. This can be used in both inpatient/outpatient settings to reproducibly rate and monitor common signs and symptoms of opiate withdrawal. COWS Download

Symptoms of acute opioid withdrawal can be managed with the following medications (however, it is not a long term treatment for opioid use disorder):

  • Anxiety: Clonidine 0.05mg q4h PRN[2]
  • Anti-emetics/anti-diarrheals
  • Muscle cramps or pain: Non-steroidal anti-inflammatory drugs such as ibuprofen, ketorolac, naproxen (250mg q6h PRN)
  • Dyspepsia: Rabeprazole 20mg qAM PRN

Opioid Use Disorder Treatment

1st line
2nd line
3rd line
Adjunctive therapy
Not recommended
See main article: Methadone

Methadone is an opioid traditionally used as maintenance therapy in opioid replacement therapy or to help with tapering in people with opioid dependence.

To avoid precipitated withdrawal, you must ensure the patient has not used any opioids for at least 12 hours; and (b) the patient is in moderate to severe withdrawal. Using the Clinical Opioid Withdrawal Scale (COWS) can be helpful for determining withdrawal severity. There is strong evidence that supports initiating Suboxone in an emergency department setting.[3][4]