Low Dose Naltrexone Print Page

Brand Name: ReVia
Scientific Names:  naltrexone

Bottom Line
Effectiveness: There are limited evidence suggestive of benefit in rheumatoid arthritis, and pain relief in patients with fibromyalgia. More research is coming however.
Safety: Has been used safely at doses for substance use disorder. More research is needed in use for rheumatic conditions.   

What is Low Dose Naltrexone?

  • Naltrexone is a prescription opioid antagonist, which means it competes with opioids to occupy the same receptors, resulting in less pain-relieving property of opioids.
  • It is used in a variety of conditions such as alcohol use disorder, opioid use disorder as a single agent medication, and when in combination with bupropion, it is used for weight loss.

What is it used for in people with rheumatic conditions?

  • It has been used for people with fibromyalgia, a condition that people with RA is more likely to get and cause more pain, however limited studies have been done in patients with RA. 

How is it thought to work?

  • Naltrexone suppresses specific immune cells thereby reduces the release of pro-inflammatory factors and ultimately reduce pain.

Does it Work? What the Science Says:

Low dose naltrexone (LDN) 4.5mg/day

  • A preliminary study (n=31, crossover design) of LDN in fibromyalgia patients demonstrated a modest reduction in pain (-1.1 from baseline 5.1); mood also improved, but there was no change in sleep. A third of patients were designated ‘responders’ (30% change in pain, fatigue, and sleep). Patients taking LDN reported side effects, the most common being vivid dreams and headaches.
    • Small preliminary study suggestive of potential benefit in fibromyalgia
  • A quasi-experimental study examined effects of LDN (<5mg/day) on medication use (DMARDs and analgesics) for patients with rheumatoid arthritis and other seropositive arthritis. For patients who filled 4 LDN prescriptions (vs. those who did not), the number of NSAID, analgesic (acetaminophen and non-opioids), and opioid use was statistically reduced. There was also a reduction in DMARD dispensations, which was not statistically significant.
    • Bigger observational study suggestive of potential benefit for RA to reduce number of pain medications used
  • Results from another placebo controlled clinical trial (crossover design) examining LDN 4.5mg on pain in 60 patients with osteoarthritis or inflammatory arthritis (rheumatoid or psoriatic) are coming soon. 

What are possible side effects and what can I do about them? 

  • Common side effects of naltrexone include when used at doses for substance use disorder:
    • Fainting, headache, sleep issues, dizziness, anxiety
    • Nausea, vomiting, change in appetite, diarrhea
    • Alterations in liver enzymes
    • Lack of energy, pain, arthritis and joint stiffness


With drugs:

  • Naltrexone is an opioid antagonist which will block pain relieving effects of opioids 

With other diseases:

  • Naltrexone should be used with caution in patients with liver or kidney problems, as patients may experience more side effects.


For more information about low dose naltrexone, consult your physician and pharmacist.

What is Rheumatology?

Rheumatologists see over 100 different types of diseases. We are known for seeing arthritis, however, we also see many other conditions.

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