Naltrexone

Aka: Naltrexone, Trexan, Revia, Vivitrol

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II. Indications

  1. Substance Dependence (especially with history of relapse)
    1. Alcoholism
    2. Opioid Dependence
    3. Must be used with an aftercare program
  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]

III. 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 or Liver failure

IV. Mechanism

  1. Very long acting opioid Antagonist (duration >24 hours)
  2. Reduces Alcohol craving
  3. Decreases impulsive use of Opioids

V. Adverse effects

  1. Hepatotoxicity (dose dependent)
  2. Nausea (10%)
  3. Headache
  4. Anxiety
  5. Sedation

VI. Efficacy

  1. Initial studies showed relapse reduction by 50%
  2. Recent large DBPCT showed no 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]

VII. Adverse effects

  1. Nausea or Vomiting
  2. Abominal pain or cramping
  3. Headache
  4. Dizziness
  5. Fatigue
  6. Insomnia
  7. Anxiety
  8. Arthralgias or myalgias
  9. Risk of lethal Opioid Overdose on relapse
    1. Decreased Opioid tolerance after use
  10. No toxicity if drinking with Naltrexone
    1. Not indicated to make them social drinkers
    2. Alcoholics tend to get less drunk on Naltrexone
  11. 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]

VIII. Monitoring

  1. Obtain serum liver transaminases periodically
    1. Baseline
    2. Repeat at 3 months, then every 3-6 months

IX. Dosage

  1. Frequency options
    1. Daily
      1. Naltrexone 50 mg orally daily
    2. Alternate days
      1. Naltrexone 100 mg orally on Monday, Wednesday and Friday
    3. 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

X. Safety

  1. Pregnancy Category C
  2. Lactation: Unknown

XI. References

  1. (2018) Presc Lett 25(1):5
  2. Hartmann (1997) Am Fam Physician 55(5):1877-9 [PubMed]
  3. Williams (2005) Am Fam Physician 72(9):1775-80 [PubMed]
  4. Winslow (2016) Am Fam Physician 93(6): 457-65 [PubMed]

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Related Studies

Cost: Medications

naltrexone (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
NALTREXONE 50 MG TABLET Generic $0.65 each
vivitrol (on 4/1/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
VIVITROL 380 MG VIAL $1,446.85 each
VIVITROL 380 MG VIAL-DILUENT $1,446.85 each
FPNotebook does not benefit financially from showing this medication data or their pharmacy links. This information is provided only to help medical providers and their patients see relative costs. Insurance plans negotiate lower medication prices with suppliers. Prices shown here are out of pocket, non-negotiated rates. See Needy Meds for financial assistance information. GoodRx is another tool for finding lower drug prices.

Related Topics in Pharmacology

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