Probenecid and Dapsone Topical: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Probenecid
No brand names on recordDapsone Topical
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
An increased risk of dapsone toxicity (hemolytic anemia, methemoglobinemia, lethargy, weakness)
Interaction Deep Dive
In a case report, the addition of probenecid to dapsone resulted in an increase of dapsone levels by 25 to 50%1.
Why it happens (mechanism)
Decreased dapsone clearance
Literature reports
1 report — tap to read
a) Probenecid appears to inhibit renal excretion of acid labile dapsone metabolites and free dapsone with consequent rise in serum levels of dapsone. Dapsone serum levels were increased by 60% over control at 4 hours and 25% over controls at 8 hours following dapsone administration 1.
Common questions
Can I take Probenecid and Dapsone Topical together?
An increased risk of dapsone toxicity (hemolytic anemia, methemoglobinemia, lethargy, weakness) Always confirm with your pharmacist or prescriber before making any change.
How serious is the Probenecid and Dapsone Topical interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Probenecid or Dapsone Topical need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (1)
- Goodwin CS & Sparell G: Inhibition of dapsone excretion by probenecid. Lancet 1969; 2:884-885. PubMed
Keep reading about Probenecid
Keep reading about Dapsone Topical
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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