Naltrexone was developed for management of opioid or alcohol dependence. This is an opioid receptor antagonist that in low doses can be used for other immunologically related disorders. The scientist who pioneered the use of naltrexone in treatment and prevention of cancer were Ian Zagon PhD and Bernadr Bihari MD.

Dr Bernard Bihari MD had researched the benefit of using Naltrexone in the following diseases: Pancreatic Cancer, Prostate Cancer, HIV/AIDS, Carcinoid, Multiple Sclerosis (MS), Hodgkin's Disease, Lupus (SLE), Rheumatoid Arthritis, Psoriasis, Lymphocytic Leukemia, Behcet's Disease, Neuroblastoma, Chronic Fatigue Syndrome, Colorectal Cancer, Chronic Fatigue Syndrome. The use of ldn for prostate cancer is still under research.

Bernard Bihari MD had used the common feature this diseases share and that is role of the immune system plays in all of them. There are many beneficial effects that suggest the use of Naltrexone in a wide variety of cancers.  The study performed by Dr. Bihari, MD showed that in the case of patients suffering of prostate cancer that take some form of hormone manipulation treatment the naltrexone administration doesn't seem to work.

There are contraindications of using low dose naltrexone when the patient takes some medication for pain (Demerol. codeine, Duragesic patch). In these cases naltrexone may interfere with the effect of pain reducing opioid narcotic. In his study Dr Bihari MD useds a substitute of one of the inflammatory drugs Vioxx (25 mb. twice daily), Celebrex (up to 200 mg. BID) that can be taken daily until the naltrexone starts to work. In the early stages ldn use for prostate cancer has proved to be an effective treatment.

One characteristic of low dose naltrexone (LDN) is that this is readily available. The recommended dosage for an average adult si 4.5 mg LDN and can be taken by mouth. The application of Low Dose Naltrexone can increase the strength of the immune system. Doctors who have documented the use of this haven't seen side effects common on other chemotherapeutic agents such as hair loss, painful mouth sores, nausea, overwhelming fatigue, and vomiting, intestinal malabsorbtion.

LDN works through a mix of three mechanisms. One of them is the one that induces the increase of beta endorphin and metenkephalin in the blood system. Another mechanism is the increase of the natural killer (NK) cell numbers and their activity and also the activation of lymphocyte. The third mechanism refers to increase of density and the number of opiate receptors in the tumor cell membranes. Althoug the use of this drug has positive results there is still more to be researched until this can become an additional treatment of prostate cancer with the other treatment methods such as chemotherapy, radiation and hormone inhibitors of cancer cell growths.

A team from Pennsylvania State University had published new findings about the use of LDN in December 1999 issue of the journal Brain Research. The study conducted by Zagon and his coleagues showed the specific cell receptor for metenkephalin one of the endorphins. Metenkephalin appears to be associated with cells undergoing renewal and is found in all tissues. Zagon found that in cancer cells may exist low level of metenkephalin or opioid receptor levels.