Naltrexone at "high" doses (50 mg or more per day) is typically prescribed for opioid dependence or alcohol dependence, as it is a strong opioid antagonist. Government regulatory agencies such as the U.S. Food and Drug Administration have approved the use of naltrexone for chronic treatment of opioid dependence and for drug detoxification.
Low-dose naltrexone, by contrast, is typically dosed at less than 5 mg per day. At such lower levels, naltrexone, rather than blocking opioid receptors, increases both their number and sensitivity, and also increases the production of the endogenous opioids that activate them, leading to an overall increase in opioid activity.
Numerous anecdotal reports have been published which describe improvements attributed to LDN treatments for a large variety of conditions and diseases. While clinical trial results are available for some claimed benefits, no review of such results has been published that recommends adoption as treatment for any disease category.
Verifiable clinical studies on low-dose naltrexone are limited, but presently there is a small and growing number of studies using LDN to treat a limited number of illnesses and conditions, with mostly positive results for the areas studied thus far, and with generally positive affirmations regarding the drug's safety.
Usually, applications of a treatment that are judged to be most promising are studied first, so it should not be assumed that favorable results in studies for one purpose in any way imply that results will be favorable for others not yet under study. Some of these studies are pilot studies, which only suggest future directions in research. A few studies have indicated a more clearly positive effect but none have yet been recommedned for clinical use.
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