dapsone and related sulfones are known to have therapeutic activity against leprosy , dermatitis herpetiformis , actinomycotic mycetoma , asthma , malaria , rheumatoid arthritis , kaposiís sarcoma , pneumocystis carinií , subcorneal pustular dermatosis and cystic acne , in patients in need of such therapy . these sulfones are also known to have therapeutic activity against memory loss in patients in need of such therapy , including patients suffering from alzheimer &# 39 ; s disease and related neurodegenerative disorders . it has now been found that new , modified - release formulations of dapsone and related sulfones may also be used that decrease side effects and increase effectiveness of the drugs . new methods are disclosed utilizing certain formulations of dapsone and related sulfones that improve the therapeutic index of said drugs . side effects of these drugs are known to those skilled in the art and include , but are not restricted to anorexia , psychosis , agranulocytosis , peripheral neuritis , hemolysis , methemoglobinemia , nausea , vomiting , headache , dizziness , tachycardia , nervousness , insomnia and skin disorders . modified - release formulations of dapsone have now been found to avoid some or all of these side effects , and to have more efficacy on potency .