//fpnotebook.com/
Naltrexone
Aka: Naltrexone, Trexan, Revia, Vivitrol
- Indications
- Substance Dependence (especially with history of relapse)
- Alcoholism
- Opioid Dependence
- Must be used with an aftercare program
- Low dose Naltrexone (0.5 mg to 4.5 mg/day) has also been proprosed for various conditions including Chronic Pain
- No rigorous evidence of benefit at these low doses and for these varied conditions, but unlikely to cause harm
- Postulated to up-regulate Opioid receptors, increas endorphin production and act as Analgesic and antiinflammatory
- May cause Opioid Withdrawal if used soon after last use of Opioids
- (2020) Presc Lett 27(4): 22
- Toljan (2018) Med Sci 6(4): 82 [PubMed]
- Contraindications
- Long-term Opioid use or Heroin dependence (until off Opioids for at least 7-10 days)
- Risk of severe withdrawal
- Opioids needed for pain control
- Hepatitis or Liver failure
- Adverse effects
- Hepatotoxicity (dose dependent)
- Nausea (10%)
- Headache
- Anxiety
- Sedation
- Mechanism
- Reduces Alcohol craving
- Decreases impulsive use of Opioids
- Efficacy
- Initial studies showed relapse reduction by 50%
- Recent large DBPCT showed no benefit with Naltrexone
- Relapse rate: 38% at 13 weeks (44% with Placebo)
- Compliance rate low: 42-44% in all groups
- Krystal (2001) N Engl J Med 345:1734-9 [PubMed]
- Adverse effects
- Nausea or Vomiting
- Abominal pain or cramping
- Headache
- Dizziness
- Fatigue
- Insomnia
- Anxiety
- Arthralgias or myalgias
- Risk of lethal Opioid Overdose on relapse
- Decreased Opioid tolerance after use
- No toxicity if drinking with Naltrexone
- Not indicated to make them social drinkers
- Alcoholics tend to get less drunk on Naltrexone
- Very broad safety profile with minimal adverse effects
- However, Opioid use is a contraindication
- Hepatotoxicity, however is a risk
- Croop (1997) Arch Gen Psych 54:1130-5 [PubMed]
- Monitoring
- Obtain serum liver transaminases periodically
- Baseline
- Repeat at 3 months, then every 3-6 months
- Dosage
- Frequency options
- Daily
- Naltrexone 50 mg orally daily
- Alternate days
- Naltrexone 100 mg orally on Monday, Wednesday and Friday
- Monthly (expensive - as much as $1300 per month in 2017)
- Vivitrol 380 mg injection every 4 weeks (appears less effective than oral dosing)
- Duration
- May need to be used for 1 year or longer
- Safety
- Pregnancy Category C
- Lactation: Unknown
- References
- (2018) Presc Lett 25(1):5
- Hartmann (1997) Am Fam Physician 55(5):1877-9 [PubMed]
- Williams (2005) Am Fam Physician 72(9):1775-80 [PubMed]
- Winslow (2016) Am Fam Physician 93(6): 457-65 [PubMed]