Pharm

Naltrexone

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Naltrexone, Trexan, Revia, Vivitrol

  • See Also
  1. Alcohol Use Disorder
  2. Opioid Use Disorder
  • Indications
  1. Substance Dependence (especially with history of relapse)
    1. Alcoholism
      1. Best used with an aftercare program
      2. However, may be started in patients who are continuing to drink
    2. Opioid Dependence
      1. Patients must abstain from Opioids for at least 7-10 days before starting
  2. Low dose Naltrexone (0.5 mg to 4.5 mg/day) has also been proprosed for various conditions including Chronic Pain
    1. No rigorous evidence of benefit at these low doses and for these varied conditions, but unlikely to cause harm
    2. Postulated to up-regulate Opioid receptors, increas endorphin production and act as Analgesic and antiinflammatory
    3. May cause Opioid Withdrawal if used soon after last use of Opioids
    4. (2020) Presc Lett 27(4): 22
    5. Toljan (2018) Med Sci 6(4): 82 [PubMed]
  • Contraindications
  1. Long-term Opioid use or Heroin dependence (until off Opioids for at least 7-10 days)
    1. Risk of severe withdrawal
  2. Opioids needed for pain control
  3. Hepatitis, decompensated Cirrhosis or Liver failure
    1. May be used in compensated Cirrhosis
  • Mechanism
  1. Very long acting opioid Antagonist (duration >24 hours)
  2. Reduces Alcohol craving
  3. Decreases impulsive use of Opioids
  • Medications
  1. Naltrexone Oral Tablet (Revia)
  2. Naltrexone Extended Release IM (Vivitrol)
  • Dosing
  1. Frequency options
    1. Oral Daily
      1. Naltrexone 50 mg orally daily (dosing range 25 to 100 mg orally daily)
    2. Oral Alternate days
      1. Naltrexone 100 mg orally on Monday, Wednesday and Friday
    3. IM Monthly (expensive - as much as $1300 per month in 2017)
      1. Vivitrol 380 mg injection every 4 weeks (appears less effective than oral dosing)
  2. Duration
    1. May need to be used for 1 year or longer
  • Adverse Effects
  1. Adverse Effects decreased with IM formulation
  2. Hepatotoxicity (dose dependent)
  3. Nausea or Vomiting (10%)
  4. Abominal pain or cramping
  5. Headache
  6. Dizziness
  7. Fatigue
  8. Insomnia
  9. Sedation
  10. Anxiety
  11. Arthralgias or myalgias
  12. Injection Site Reaction (IM, Vivitrol)
  13. Risk of lethal Opioid Overdose on relapse
    1. Decreased Opioid tolerance after use
  14. No toxicity if drinking with Naltrexone
    1. Not indicated to make them social drinkers
    2. Alcoholics tend to get less drunk on Naltrexone
  15. Very broad safety profile with minimal adverse effects
    1. However, Opioid use is a contraindication
    2. Hepatotoxicity, however is a risk
    3. Croop (1997) Arch Gen Psych 54:1130-5 [PubMed]
  • Safety
  1. Pregnancy Category C
  2. Lactation: Unknown
  • Efficacy
  1. Initial studies showed relapse reduction by 50%
  2. IM monthly Naltrexone injection (Vivitrol) appears more effective and with fewer adverse effects than oral daily (Revia)
    1. Return to Alcohol use 150 days for IM (50 days for oral)
    2. Leighty (2019) Mental Health Clin 9(6): 392-6 [PubMed]
  3. Decreases heavy drinking days
    1. Rosner (2010) Cochrane Database Syst Rev (12):CD001867 [PubMed]
  4. Some studies have shown marginal benefit with Naltrexone
    1. Relapse rate: 38% at 13 weeks (44% with Placebo)
    2. Compliance rate low: 42-44% in all groups
    3. Krystal (2001) N Engl J Med 345:1734-9 [PubMed]
  • Monitoring
  1. IM Naltrexone patients should have a medic alert card
    1. Consult pain management in patients with Acute Severe Pain
  2. Obtain serum liver transaminases periodically
    1. Baseline
    2. Repeat at 3 months, then every 3-6 months
  • Drug Interactions
  1. May be used in combination with other agents used in Substance Abuse
    1. Examples: Acomprosate, Topiramate, Gabapentin
  2. Opioids
    1. Severe withdrawal risk (see contraindications as above)
  • Resources
  1. Naltrexone Tablet (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=06ff2d5a-e62b-4fa4-bbdb-01938535bc65
  2. Naltrexone IM Injection (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=cd11c435-b0f0-4bb9-ae78-60f101f3703f
  • References
  1. (2018) Presc Lett 25(1):5
  2. Hartmann (1997) Am Fam Physician 55(5):1877-9 [PubMed]
  3. Poorman (2024) Am Fam Physician 109(1): 71-8 [PubMed]
  4. Williams (2005) Am Fam Physician 72(9):1775-80 [PubMed]
  5. Winslow (2016) Am Fam Physician 93(6): 457-65 [PubMed]