Mode of action of dapsone?

How does dapsone work (its main mechanism of action)?

Dapsone (diaminodiphenylsulfone) is an antibacterial and antiprotozoal drug that works by interfering with folate (folic acid) metabolism inside susceptible microorganisms. It inhibits the enzyme dihydropteroate synthase (often discussed in relation to folate pathway disruption), which blocks the production of folate needed for DNA synthesis and cell growth. This folate blockade is the core basis for its antimicrobial effect.

Why does dapsone require activation?

Dapsone must be chemically reduced inside susceptible cells to form reactive metabolites that then disrupt microbial processes related to folate metabolism. This activation step helps explain why dapsone’s effectiveness depends on drug handling in the organism and why adverse effects can occur in the host as well.

What organisms has this mechanism been used against?

Because its action targets folate-related survival pathways, dapsone has been used clinically for infections where those pathways are crucial for organism growth, including certain mycobacterial infections (notably leprosy) and Pneumocystis jirovecii pneumonia in specific treatment settings.

What patient side effects connect to its mechanism (and activation)?

Some of dapsone’s well-known toxicities relate to its redox activity and the formation of reactive metabolites during metabolism. This is why patients with conditions that affect their ability to handle oxidative stress (for example, G6PD deficiency) are at higher risk for hemolysis when taking dapsone.