How does dapsone work (its main mechanism of action)?
Dapsone (4,4'-diaminodiphenylsulfone) is an antibiotic and anti-inflammatory drug. Its antimicrobial effect comes from disrupting how susceptible microbes use folate, blocking steps needed to make folate-derived molecules.
What does dapsone do to folate metabolism in bacteria?
Dapsone acts like a sulfonamide-class drug by interfering with folate synthesis pathways. In susceptible organisms, it inhibits formation of dihydrofolate and related folate intermediates, which prevents the microbe from producing the nucleotides needed for DNA synthesis and growth.
What is dapsone’s mechanism in inflammatory diseases (why is it used for leprosy and dermatitis herpetiformis)?
Beyond killing susceptible organisms, dapsone reduces neutrophil-mediated inflammation. This anti-inflammatory effect is one reason it works in conditions such as dermatitis herpetiformis, where the symptomatic skin inflammation is driven by immune activity rather than only by microbial infection.
Does dapsone work the same way for all pathogens?
No. Dapsone’s antimicrobial activity depends on whether the target pathway and drug-activation steps are present in the organism. Drug resistance can also arise through changes that reduce the drug’s effective inhibition of folate pathways.
If you’re looking for a one-line summary
Dapsone inhibits folate synthesis in susceptible bacteria, and it also has an anti-inflammatory effect that helps control neutrophil-driven inflammation in some immune-mediated skin conditions.