Low-Dose Naltrexone (LDN)

Low-Dose Naltrexone, usually abbreviated LDN, is used fairly often in treating some of the diseases that co-occur with MCAS and even MCAS itself.  It is considered to be quite safe.  In this capacity it is usually used to treat chronic pain, particularly in cases of Fibromylagia and Ehlers-Danlos Syndrome.  The drug was originally used to treat heroin addiction (and sometimes alcohol addiction) by reducing the symptoms of withdrawl.  Later it was discovered that very low doses could stop an HIV infection from becoming AIDS.  LDN has been found to have anti-inflammatory properties, anti-depressive properties, and anti-anxiety properties.  Doctors began using it in this low dose form to treat other things including Crohn's Disease, Fibromyalgia, MS, some skin disorders, and lately even in treating some cancers.  While the ways that LDN helps in many diseases is not well understood, it is clear that it is very safe and able to help many people suffering a wide range of diseases/disorders.

LDN is an immune-modulator rather than an immune-suppressant.  Drugs that are immune-suppressors treat the symptoms of some diseases by suppressing the body's production of inflammatory molecules, suppressing the body's ability to fight infection.  This may put a disease into a less active state but it does not actually treat the disease by addressing the underlying cause, and it can leave the person dangerously susceptible to infection.  By up-regulating the expression of certain cellular receptors, LDN actually changes the immune system itself, making it more able to respond appropriately to a challenge.  It can be said to "modulate" the immune system because it reduces inflammation while supporting a person to be more healthy in an overall sense.  

LDN works by blocking the opiate receptors on cells for about 3 hours at a time, which tricks the body into thinking that there aren't enough receptors, causing it to produce more.  The body also responds by producing more endorphins, which are the body's own chemicals to reduce pain and cause a state of well-being.  It reduces inflammation in the brain and CNS by acting on the TLR-4 receptors on immune cells called glial cells, causing them to reduce their production of pro-inflammatory molecules including IL-6.  This provides an anti-inflammatory effect on the brain but this benefit can include other parts of the body because the brain controls so much of the body.

The only two side effects that seem to be reported much are that it can cause people to have vivid dreams,and that when a person begins taking it, during the first few weeks it can cause insomnia.  However, there are also some people who report that it causes there sleep to improve.  Some patients experience benefits from LDN very soon after starting it, while it can take longer in others.  It should be tried for at least 2 to 3 months before deciding that it isn't working for a patient.  

Low dose Naltrexone for induction of remission in inflammatory bowel disease patients

Low-dose naltrexone for the treatment of fibromyalgia: Findings of a small, randomized, double-blind, placebo-controlled, counterbalanced, crossover trial assessing daily pain levels

The effect of low-dose naltrexone on quality of life of patients with multiple sclerosis: a randomized placebo-controlled trial

Naltrexone a potential therapeutic candidate for COVID-19

Low-dose naltrexone in the treatment of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)
"The high frequency of treatment response and good safety profile observed in this retrospective open label study could prompt prospective controlled studies to confirm the feasibility of LDN in alleviating ME/CFS symptoms."

Naltrexone at low doses (LDN) and its relevance to cancer therapy
"Considering the increase in the number of anecdotal reports of activity, there will likely be a bigger drive toward using LDN in the oncological setting. These reports support clinical trials of LDN in cancer, especially when given in combination with certain chemotherapy."

"We review three mechanisms through which LDN can influence cancer progression; namely, (a) antagonism of receptors to which LDN binds, which include toll-like receptors 7–9 that lead to IL-6 suppression b) modulation of immune function in patients; and c) direct inhibition of signaling pathways involved in cancer cell control, including the priming of pro-apoptotic pathways."