From the Guidelines
Low dose naltrexone (LDN) is recommended for neuropathic pain management, starting at 1.5 mg at bedtime with gradual bi-weekly increase of 1.5 mg to a final maximum dose of 4.5 mg, due to its effectiveness in reducing pain and improving quality of life, as shown in a recent study 1. The typical dosage ranges from 1-4.5 mg daily, taken at bedtime, with 4.5 mg being the most common effective dose.
- LDN works differently from standard naltrexone doses by temporarily blocking opioid receptors, which paradoxically leads to increased endorphin production and reduced inflammation through glial cell modulation, as an antagonist to toll-like receptor 4 that has been linked to neuropathic pain, reducing the release of pro-inflammatory cytokines and modulating microglial activity 1.
- This anti-inflammatory effect may explain its benefit in neuropathic pain conditions, including fibromyalgia, complex regional pain syndrome, low-back pain, and painful diabetic neuropathy.
- Patients should be aware that benefits may take 1-2 months to appear, and LDN should be avoided by those on opioid medications as it can precipitate withdrawal.
- Common side effects include headache, tachycardia, and vivid dreams, which can be minimized by gradual dose increase.
- While some patients report significant improvement, particularly those with inflammatory or autoimmune-related neuropathic pain, LDN represents a potentially useful option with minimal side effects for patients who haven't responded to conventional treatments, as supported by a RCT of 31 patients with fibromyalgia, where use of LDN 4.5 mg resulted in significant decrease of pain and improved satisfaction with life as compared to placebo 1.
From the Research
Low-Dose Naltrexone for Neuropathic Pain
- Low-dose naltrexone has been used off-label for chronic pain management, including neuropathic pain, at doses of 4.5 mg daily 2.
- A study found that low-dose naltrexone resulted in a small decrease in pain scores, with an average change of -0.83, and was generally well-tolerated 2.
- Another study suggested that low-dose naltrexone could be a viable treatment option for chronic pain, including neuropathic pain, due to its minimal adverse effects and low cost 3.
- A retrospective cohort study found that low-dose naltrexone was effective in reducing pain scores in patients with chronic pain, including those with neuropathic pain, with a significant pain reduction of -37.8% 4.
- The use of low-dose naltrexone for neuropathic pain is also mentioned in a Delphi study, which suggested that it could be a potential treatment option for patients who do not respond to standard treatments 5.
Efficacy and Safety
- Low-dose naltrexone has been found to be effective in reducing pain scores in patients with neuropathic pain, with a number needed to treat (for 50% pain reduction) of 3.2 4.
- The safety profile of low-dose naltrexone is generally favorable, with minimal adverse effects reported, including vivid dreams, drowsiness, dizziness, and nausea 2, 3.
- Low-dose naltrexone has been found to be well-tolerated, with approximately half of patients still taking it at the time of chart review 2.
Comparison to Other Treatments
- Gabapentin is a commonly used treatment for neuropathic pain, and has been found to be effective in reducing pain scores, with a number needed to treat (for 50% pain reduction) of 6.7 6.
- Low-dose naltrexone may be considered as an alternative to gabapentin, due to its potential for fewer adverse effects and lower cost 3.