However, dapsone can potentially cause severe side effects, meaning that sometimes steroids or other antibiotics should be used instead, although these alternative treatments are much less effective.An August 2015 review notes that dapsone is reported to be effective against generalized granuloma annulare.Dapsone has been used as a monomer in the design of dye adsorbent polymers. Contraindications and precautions
People with porphyria, anemia, cardiac disease, lung disease, HIV infection, G6PD deficiency, and liver impairment are at higher risks of adverse effects when using dapsone. Adverse effects
Hypersensitivity reactions occur in 1.4% of persons treated with dapsone, and can be fatal in medical settings with low resources. It is a form of severe cutaneous adverse reactions (SCARs) in which a SCARs disorder, primarily the DRESS syndrome or a DRESS syndrome-like reaction occurs. Blood
Hemolysis is the most prominent side-effect, occurring in about 20 % of patients treated with dapsone, although it is dose-related. It may lead to hemolytic anemia and methemoglobinemia. The side-effect is more common and severe in those with glucose-6-phosphate dehydrogenase deficiency, leading to the dapsone-containing antimalarial combination Lapdap being withdrawn from clinical use. A case of hemolysis in a neonate from dapsone in breast milk has been reported. Agranulocytosis occurs rarely when dapsone is used alone but more frequently in combination regimens for malaria prophylaxis. Abnormalities in white blood cell formation, including aplastic anemia, are rare, yet are the cause of the majority of deaths attributable to dapsone therapy.Methemoglobinemia occurs in about 15 % of patients treated with long-term dapsone at standard doses (100 mg/day).
Further investigation into the involved chemicals opened the way to sulfa drug and sulfone therapy, first with the discovery of sulfanilamide, the active agent of prontosil, by Daniel Bovet and his team at Pasteur Institute (1935), then with that of dapsone independently by Ernest Fourneau in France and Gladwin Buttle in the United Kingdom. Proposed use in antimalarial drugs
The spread of drug-resistant malaria in Africa has encouraged the development of new, low-cost antimalarial drugs. Plasmodium falciparum, one of the Plasmodium species that causes malaria, has developed resistance both to chloroquine and sulfadoxine/pyrimethamine, two of the most common treatments for malaria. Artemisinin, another antimalarial drug, had been developed in the 1980s but was too expensive for large-scale use. This led GlaxoSmithKline to develop Lapdap, a combination drug consisting of chlorproguanil and dapsone. Lapdap was licensed in the United Kingdom starting in October 2003.One advantage of Lapdap was that chlorproguanil and dapsone are both low-cost drugs. Another was that by virtue of being a combination drug, it was less likely to cause drug resistance. However, because dapsone causes hemolytic anemia in patients with G6PD deficiency, and because G6PD deficiency affects 10-25% of the population of sub-Saharan Africa, it was discovered that Lapdap is not safe for use in Africa. It was available in many African countries for four years before GlaxoSmithKline took it off the market in February 2008. Dapsone gel
Dapsone had been reported in a few cases to effectively treat acne, but the risk of hemolytic anemia kept it from being widely used for this purpose.