Abstract: Multiple sclerosis in a human patient is treated by the administration via a pharmacologically effective route of an essentially pure opiate receptor antagonist, preferably an essentially pure opiate receptor antagonist exhibiting a substantially higher blocking effectiveness against Mu opiate receptor sites than against Delta receptor sites, exempliefied by Naltrexone and Naloxone, at a low dose concentration which produces therapeutic results corresponding to those produced by Naltrexone when administered in the range of about 1 mg to about 10 mg and at a lelel at which Delta blocking activity is small while Mu blocking activity is significant and most preferably substantially exclusive.

Abstract: An improvement in a method of treating an HIV/AIDS infection in human patients in which the patient receives antiretroviral therapy and is consequently subjected to significant risk of developing the lipodystrophy syndrome in one or more of its characteristics. This risk is reduced, and pre-existing signs of such syndrome from past therapy can be substantially reversed, by the concurrent administration by a therapeutically effective mode of an essentially pure opiate receptor antagonist such as Naltrexone and Naloxone at a low level dosage.

Abstract: Cancer of the prostate in human male patients even at an advanced state with metastasis to other organs, is treated by the administration, preferably at bedtime, to the patient by a pharmacologically effective mode of an essentially pure opiate receptor antagonist, typified by Naltrexone and Naloxone, exerting substantially higher blocking action for Mu opiate receptor sites than against Delta opiate receptor sites at a low dose concentration which produces therapeutic results corresponding to those obtained by the administration of Naltrexone at a low dosage level in the range of 1.0 mg. to 10 mg. per day and at which Delta receptor blocking activity is at most small and Mu receptor blocking activity is substantial. Naltrexone is suitable for oral administration and is preferred.

Abstract: Lymphoproliferative syndrome, including such diseases as malignant lymphoma, chronic lymphocytic leukemia, Hodgkin's lymphoma, and non-Hodgkin's lymphoma, is treated in human patients by the administration by a pharmacologically effective mode or route of an essentially pure opiate receptor antagonist, typified by Naltrexone and Naloxone, exerting substantially higher blocking action for Mu opiate receptor sites than against Delta opiate receptor sites at a low dose concentration which produces therapeutic results corresponding to those obtained by the administration of Naltrexone at a low dosage level in the range of 1.0 mg. to 10 mg. and at which Delta receptor blocking activity is at most small and Mu receptor blocking activity is significant and most preferably substantially exclusive. Naltrexone is suitable for oral administration and is preferred.

Abstract: Chronic herpes virus infections are treated in human patients by the administration by a pharmacologically effective mode or route of an essentially pure opiate receptor antagonist, preferably an essentially pure opiate receptor antagonist exhibiting substantially higher blocking action against Mu opiate receptor sites than against Delta receptor sites, exemplified by Naltrexone and Naloxone, at a low dose concentration which produces therapeutic results corresponding to those produced by Naltrexone when administered in the range of 1 mg to 10 mg and at which Delta receptor blocking activity is at most small while Mu receptor blocking activity is significant and most preferably exclusive.

Abstract: Chronic herpes viral infections, including chronic genital herpes caused by the herpes simplex virus, Type 2, and chronic infections due to the Epstein-Barr virus, chronic fatigue syndrome, chronic inflammatory connective tissue disease, including rheumatoid arthritis and systemic lupus erythematous and related diseases, and multiple sclerosis are treated by the administration via a pharmacologically effective route of an essentially pure opiate receptor antagonist, preferably an essentially pure opiate receptor antagonist exhibiting a substantially higher blocking effectiveness against Mu opiate receptor sites than against Delta receptor sites, exemplified by naltrexone and naloxone, at a low dose concentration, corresponding to about 1-10 mg per day for naltrexone, at which concentration Delta blocking activity is small, while Mu blocking activity is significant.

Abstract: A treatment method for humans infected with HTLV-III (AIDS) virus, including patients clinically diagnosed as suffering from AIDS, those suffering from AIDS-related complex (ARC) as distinguished from AIDS itself, those exhibiting a positive serum test from AIDS virus coupled with a significant measurable dimunition in immunological function, and those simply showing a positive serological test for the AIDS virus without other symptomatic indications, involves the administration, preferably orally where appropriate, of a small but effective amount in the range corresponding to about 1.0-5.0 mg per day for naltrexone, of an opiate receptor antagonist which at the indicated levels exhibits substantially antagonistic or blocking action exclusively upon Mu opiate receptors.