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: 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.