Dapsone and Rifampin interaction
Dapsone and Rifampin: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Dapsone label · effective 2026-07-20
Drug Interactions: Rifampin lowers dapsone levels 7 to 10-fold by accelerating plasma clearance; in leprosy this reduction has not required a change in dosage.
From the Rifampin label · effective 2026-05-05
Decrease exposure Other Drugs Enalapril Decrease active metabolite exposure Chloramphenicol Concomitant use with rifampin in 2 children Decrease exposure Clarithromycin Decrease exposure Dapsone Rifampin has been shown to increase the clearance of dapsone and, accordingly, decrease dapsone exposure.
Rifampin has also been shown to increase the production of the hydroxylamine metabolite of dapsone which could increase the risk of methemoglobinemia.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.