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Chapter I. History of Low Dose Naltrexone Naltrexone was created in 1963 as an opioid receptor blocker. This means naltrexone binds to opiate receptor and neutralizes the action of opiates on the opiate receptor. Naltrexone was approved by FDA in 1984 for the treatment of opioid addiction. The typical daily dosage for opioid addiction is 50 to 100 mg daily. Low Dose Naltrexone or LDN refers to daily dosages of naltrexone that are between 1.5 is 4.5 mg. Basic science work examining the use of opioid antagonists for treating other diseases did not appear until the late 1980s, and the first published LDN trial in humans was presented in 2007. Since that time, LDN has been studied and has been slowly gaining attention as a possible treatment for some chronic medical conditions. Currently, the best documented scientific use of LDN is in treating autoimmune conditions such as multiple sclerosis, Crohn’s disease, and Hashimoto’s thyroiditis. However, late Bernard Bihari, MD has also documented use of LDN for treating HIV and cancer. The review of literature revealed one case study of long-term survival of a pancreatic cancer patient with liver metastases treated with LDN and alpha lipoic acid for four years resulting in patient surviving without symptoms and patient being able to work. Follow up study documented survival of the original patient to 78 months and also shared two more cases of patients with metastatic cancer responding positively to the LDN plus alpha lipoic acid treatment.

Another documented use of LDN is for treating obesity. Contrave, a new medication approved to treat obesity in 2014, combines LDN and bupropion in a sustained release formula. Both bupropion and LDN individually have shown evidence of weight loss and the combination aims to create a synergistic effect. Contrave is a sustained release formulation of LDN and bupropion. The FDA has placed a boxed warning onto Contrave stating that it may affect mood and it may increase the likelihood of suicide. This potential adverse effect is most probably due to bupropion as such adverse effects have been observed with medications designed to treat mood disorders. In addition to LDN, there is also ultralow dose naltrexone using microgram dosing (one millionth of a gram). Ultralow dose naltrexone when given with narcotic medication appears to enhance the duration and depth of pain relief while minimizing side effects of narcotic medications. Investigation of this phenomenon has resulted in developing Oxytrex – an investigational medication combining oxycodone with ultralow dose naltrexone. A phase III clinical trial has shown that Oxytrex has been as effective in providing pain relief while causing less physical dependence than oxycodone alone.

Yoon Hang Kim MD

Direct Integrative Care

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