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Opioid use disorder
Background
Overview
Definition
OUD is defined as a pattern of recurring opioid use leading to clinically significant impairment or distress.
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Pathophysiology
The positive reinforcing effects of opioid use are mediated by indirect downstream activation of dopamine receptors. Repeated use ultimately leads to physiological dependence with tolerance, and withdrawal if use is ceased.
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Epidemiology
In the US, the rates of past-year non-medical opioid use, heroin use, and heroin abuse are estimated at 4,240, 260, and 190 per 100,000 persons, respectively.
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Disease course
The development of opioid dependence mirrors other drug dependencies. Possible warning signs may include changes in peer group, decreasing involvement in social/leisure activities, isolation from family/old friends, mood changes, and increased frequency of negative behaviors, including criminal acts. Development of tolerance leads to consumption of escalating opioid doses, which increases the risk of respiratory depression and death.
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Prognosis and risk of recurrence
OUD is associated with an increase in mortality, with an estimated standardized mortality ratio of 14.66 (95% CI, 12.82-16.50) In the US, out of 100 daily deaths due to drug overdose, nearly 50 deaths are due to prescription opioids, and 20 are due to heroin overdose.
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Guidelines
Key sources
The following summarized guidelines for the evaluation and management of opioid use disorder are prepared by our editorial team based on guidelines from the American Academy of Family Physicians (AAFP 2025,2024), the Japanese Gastroenterological Association (JGA 2025), the Canadian Research Initiative in Substance Misuse (CRISM 2024,2019), the American Heart Association (AHA 2023), the Society of Obstetricians and Gynaecologists of Canada ...
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Screening and diagnosis
Indications for screening: as per DoD/VA 2021 guidelines, insufficient evidence to recommend for or against screening for OUDs in primary care to facilitate enrollment in treatment.
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Indications for screening (PEER)
Diagnosis
Diagnostic investigations
Initial clinical assessment: as per ASAM 2020 guidelines, obtain a comprehensive assessment for treatment planning. Do not delay or preclude pharmacotherapy for OUD because of the completion of all assessments. Complete assessments soon after initiating pharmacotherapy, if not completed before that.
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Initial laboratory testing
Urine drug testing
Urine drug testing (PEER)
Screening for comorbidities
Medical management
General principles: as per AAFP 2025 guidelines, do not require behavior therapy as a condition for receiving medications for OUD.
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Setting of care (primary care)
Setting of care (emergency department)
Setting of care (residential care)
Withdrawal management
Withdrawal management (PEER)
Buprenorphine/naloxone
Buprenorphine/naloxone (PEER)
Methadone
Methadone (PEER)
Slow-release oral morphine
Injectable opioid agonists
Naltrexone
Naltrexone (PEER)
Alpha-adrenergic agonists
Cannabinoids
Nonpharmacologic interventions
Psychosocial therapy
As per CRISM 2024 guidelines:
Consider offering psychosocial therapy, interventions, and support as adjunct treatments to opioid agonist therapy to increase treatment retention. Do not make psychosocial treatment a mandatory component of standard treatment for OUD, and do not allow it to prevent access to opioid agonist therapy.
B
Offer harm reduction strategies (such as provision of sterile consumption equipment, overdose prevention education, and access to take-home naloxone kits) as part of the continuum of care in patients with OUD.
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Psychosocial therapy (PEER)
Mutual help programs
Mindfulness-based therapies
Technology-based interventions
Specific circumstances
Female patients: as per SOGC 2023 guidelines, ask females about their use of opioids when they present for pain management. Obtain screening and offer brief intervention and referral to treatment.
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Pregnant patients
Patients with other substance use disorders
Patients with opioid-induced constipation
Patients with opioid overdose
Patient education
General counseling: as per CAEP 2020 guidelines, offer overdose education during the emergency department visit in all patients at risk of opioid overdose and persons likely to witness an opioid overdose in the future, such as friends, partners, and family members of patients using opioids.
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Preventative measures
Safe opioid prescribing
As per CAEP 2020 guidelines:
Establish opioid prescribing policies in emergency departments aligning local practices by providing guidance on screening, risk assessment, opioid selection, and judicious course duration to reduce the risk of subsequent OUD.
E
Counsel patients on the risks of adverse events, overdose, and dependence and provide instructions for safer storage and disposal when prescribing opioids in the emergency department.
E