Opioid Use Disorder

General Overview

• Screening
  • How many times in the past year have you used an illegal drug, or used a prescription medication for non-medical reasons?
    • If greater than zero for opioids, consider detailed assessment for Opioid Use Disorder (OUD)
  • See Substance Use
• Prescription Opioids are commonly abused (reasonable estimates of OUD after initial prescription 4.7%) , and a major cause of opioid-related overdose
  • See prescription medication section in Substance Use page
  • Very limited evidence for the use of opioids in chronic non-cancer pain, due to high risks and minimal benefits
    • Common adverse effects: Nausea, vomiting, constipation, drowsiness, dizziness, pruritus
    • Complications: Neuroendocrine (hypogonadism, erectile dysfunction, amenorrhea), worsened sleep apnea, hyperalgesia, overdose/intoxication and respiratory depression (see Poisoning), physiological dependence and withdrawal
  • Optimize nonopioid pharmacotherapy and nonpharmacologic therapy
  • If decision for trial of opioids, consider
    • Titrate to lowest effective dose, restricting to less than 90 morphine milligram equivalent (MME) daily, ideally less than 50 MME daily
    • If ineffective, consider rotation, or tapering and discontinuation
  • Consider assessing for OUD with Prescription Opioid Misuse Index (POMI)

Opioid Withdrawal

💡 Opioid withdrawal causes severe discomfort but is usually NOT life threatening and usually does not cause altered mental status

• Time to peak and duration of symptoms highly dependent on the half-life of the drug involved (fentanyl < heroin < methadone)
  • Typically starts within hours after use, peaks 36-72h, subsides after 1 week
• Assess symptoms with clinical and subjective opioid withdrawal scales: COWS and SOWS
  • History: Restlessness, rhinorrhea, lacrimation, myalgias, arthralgias, nausea, vomiting, abdominal pain, diarrhea
  • Physical exam: Mydriasis (dilated pupils), yawning, diaphoresis, piloerection
• Withdrawal management alone (“detox”) without long-term opioid agonist therapy or comprehensive continuing addiction care is not recommended due to high risk of relapse, HIV infection and overdose death
  • If detoxification is pursued, consider taper > 1 month rather than a rapid <1 week taper to prevent relapse
• Treatment
  • Discuss past use of treatments, including OAT, psychosocial interventions
  • Discuss community supports
  • Discuss goals
  • OAT (specifically Buprenorphine/naloxone) and adjunctive psychosocial treatment is generally recommended as first-line treatment for OUD

Pharmacotherapy

• Discuss long-term opioid agonist therapy (OAT) with patients for treatment of clearly diagnosed opioid use disorder
  • Buprenorphine/naloxone (Suboxone), generally preferred over methadone due to safety profile
    • Indication: Patient must be in withdrawal (>12-24h for short-acting opioids, >48-72h for long-acting)
    • Contraindications: Allergy, pregnancy, severe liver dysfunction
    • Adverse effects: Headache, insomnia, diaphoresis, nausea, abdo pain
    • Day 1: 4mg/1mg SL (BUP/NLX) once in mild withdrawal, then add 2/0.5mg q2h if withdrawal symptoms (do not exceed 12mg/day)
    • Day 2+: Same dose as sum of previous day, increase by max of 4mg each day until steady state (>16/4mg daily rarely needed, do not exceed 24mg day)
  • Methadone (1mg per 4mg of morphine or typical starting dose of 10-30mg methadone)
    • Can be started immediately
    • Contraindications: Allergy, history or increased risk of prolonged QT
    • Adverse effects: Drowsiness, dizziness, nausea, constipation, diaphoresis, peripheral edema, sexual dysfunction
    • Dose titrated 10mg increments every 3-5d over next several weeks until 80mg/d, then titrate slowly over 1-2w
  • Consider take-home doses (2-7 days) PRN if needed and stable
  • Optimal duration unknown, and may be indefinite
    • If patients wish to discontinue OAT, consider slow taper over months to years
• Opioid antagonist (Naltrexone)
  • Consider in mild opioid use disorder, safety-sensitive occupations (drivers), criminal justice settings (in prison), opioid free for 7-10 days , who are unable/unwilling to take opioid agonist therapy, or third-line (after failed OAT)
  • Naltrexone 25-50mg blocks all opiate receptors x24h (can be PO daily or long-acting injectable)
• Consider ECG, bhCG, urine drug testing, LFTs, STI (HIV, Hep B/C, G/C, Syphilis) +/- TB
• Consider treatment agreements
  • Contingency management: “rewards” for desired behaviour (eg, vouchers or prizes) or loss of privileges for undesired behaviour (eg, loss of medication carries for positive urine drug screening results)
    • Positive effect likely from positive contingencies increases retention in treatment (RR = 1.15, 95% CI 1.09 to 1.21)
• Offer take-home naloxone (THN) kit to all patients (or their caregivers)
• Consider other harm reduction services (sterile injection supplies)
• Adjunctive symptomatic management for withdrawal symptoms (e.g., anxiety, nausea, pain, diarrhea)
• Psychosocial support should be routinely offered (but not mandatorily required), including standard counseling (15 minutes) is more effective in retention than no or minimal counseling
  • Motivational interviewing, CBT, 12-step program, addiction counseling program, Narcotics Anonymous

Follow-up

• At each visit discuss
  • Adherence to treatment plan
  • Withdrawal symptoms, cravings
  • Opioid or substance use (especially sedating agents, eg. alcohol, benzodiazepines)
  • General symptoms (sleep, mood)
  • Function (home, social, work)
• Consider vaccines for Hep A/B if relevant
• Relapse is common, and should not be seen as failure!
  • Consider switching to another pharmacotherapy (eg. Suboxone to Methadone, or Methadone to Suboxone)