Naltrexone is an opiate antagonist that is taken orally to block opioid docking sites (receptors) on cells. It is approved by the U.S. Food and Drug Administration (FDA) for the treatment of addictions to opioids and alcohol. At significantly lower doses, Naltrexone has been used off-label as a treatment for various types of cancers, HIV/AIDS, Parkinson’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis (ALS), emphysema, as well as (MS) and other autoimmune diseases.
There has been limited clinical study of low-dose naltrexone (LDN) to treat MS. Most of the studies completed have not been randomized controlled trials, which show the most reliable results. Of the studies completed, many show LDN to be safe and easily tolerated but few show improvements to the disease process itself. Some studies have demonstrated an improvement in quality of life, particularly in pain and fatigue management. Because the evidence to support the effectiveness of LDN in treating MS is lacking, it should not be used as a disease modifying therapy. However, it would be reasonable to consider using LDN off-label for the management of fatigue or pain.
Naltrexone can cause liver damage, but it is most often seen at high doses and not the low dose. Other side effects include nausea, vomiting, abdominal pain, decreased appetite, constipation, headache, fatigue, insomnia, dizziness, depression and anxiety. Serious side effects that should be reported right away to a healthcare professional include confusion, hallucinations, blurred vision and sever vomiting or diarrhea.