The drug Naltrexone was originally approved in 1984 at the 50mg. dose for helping heroin and opium addicts. It works by blocking the reception of the opioid hormones beta-endorphin and metenkephalin in the cells of the the immune system. In 1985 Dr. Bernard Bihari, MD discovered that a much smaller does (3 mg.) when taken at bedtime produced a brief blockage of opioid receptors between 2 and 4 AM. This stimulates the pituitary to increase its production of endorphin and enkephalin which is beneficial to the immune system. Low Dose Naltrexone or LDN has shown to be effective in helping persons with HIV/AIDS, cancer, autoimmune diseases, multiple sclerosis, and Chronic Fatigue and Fibromyalgia Syndromes. Endorphins also regulate the contractions of the intestinal walls and because of this LDN is used as a prokinetic agent in the treatment of Small Intestinal Bacterial Overgrowth, a condition that causes Irritable Bowel Syndrome and other gastrointestinal problems common in persons with CFS and FSM.
Because Naltrexone is a generic drug that is without patent protection, no pharmaceutical company will bear the expense of large clinical trials necessary for FDA approval of LDN however over the last few years there have been a growth in small studies of LDN for conditions including one for fibromyalgia by Stanford Medical School in 2009. In the study six out of ten participants felt significantly better than placebo reducing their symptoms of pain, fatigue, stress, sleep problems gastrointestinal complaints, and headaches. For more information on the study go to: http://snapl.stanford.edu/research/ldn.html. Similar results were replicated by surveys on treatment effectiveness by both fibromyalgia and chronic fatigue patients by the advocacy group "Cure Together" http://curetogether.com.
Low levels endorphins are generally present in diseases associated with immune deficiencies. In this way this relatively safe drug can be helpful for a variety of conditions. The therapeutic dose of LDN is 1.5-4.5 mg. taken nightly. Larger doses block opioid receptors for too long a period of time to be effective. LDN needs to prescribed by a physician and prepared by a reliable compounding pharmacy. The drug is inexpensive - approximately $38 for one month's supply and has no known side effects except more vivid dreams.
Although I am generally opposed to the treatment of CFS and FMS with pharmaceutical drugs, LDN falls into a different category. It is relatively safe, inexpensive and appears to have no effects in the majority of users. I personally know of several persons who have benefited from taking LDN however over time the drug seemed to loose its effectiveness for them. It was prescribed for me as a prokinetic agent for treating SIBO. I took it for three weeks but discontinued because it disturbed my sleep. For more information go to: http://lowdosenaltrexone.org/