Dapsone, also known as 4,4-sulfonyldianiline (SDA) or diaminodiphenyl sulfone (DDS), is an antibiotic commonly used in combination with rifampicin and clofazimine for the treatment of leprosy. It is a second-line medication for the treatment and prevention of pneumocystis pneumonia and for the prevention of toxoplasmosis in those who have poor immune function. Additionally, it has been used for acne, dermatitis herpetiformis, and various other skin conditions. Dapsone is available both topically and by mouth.Severe side effects may include a decrease in blood cells, red blood cell breakdown especially in those with glucose-6-phosphate dehydrogenase deficiency (G-6-PD), or hypersensitivity. Common side effects include nausea and loss of appetite. Other side effects include liver inflammation, methemoglobinemia, and a number of types of skin rashes. While the safety of use during pregnancy is not entirely clear some physicians recommend that it be continued in those with leprosy. It is of the sulfone class.Dapsone was first studied as an antibiotic in 1937. Its use for leprosy began in 1945. It is on the World Health Organizations List of Essential Medicines. The form, which is taken by mouth, is available as a generic drug and not very expensive. Medical uses
Infections
Dapsone is commonly used in combination with rifampicin and clofazimine for the treatment of leprosy. It is also used to both treat and prevent pneumocystis pneumonia (PCP).
For many years scientists attempted to develop a topical formulation of dapsone that would be as effective against acne as oral dapsone, but without the hemolysis side effect. This was difficult to accomplish because dapsone is highly insoluble in aqueous solvents. In the early 2000s QLT USA developed Aczone, a 5% dapsone gel that was shown to be effective against acne without causing clinically significant declines in hemoglobin levels, even in subjects with G6PD deficiency. In February 2016, the FDA approved a 7.5% dapsone gel. This higher strength has the advantage of a once-daily application, versus twice-daily application of the 5% formulation. Other uses
Dapsone also find uses as a curing agent in the manufacture of paints, adhesives, composites, powder coats, printed circuit boards, and imine-based vitrimers. See also
Promin, a more-soluble derivative

References
External links
"Dapsone". Drug Information Portal. U.S. National Library of Medicine.