Dapsone Topical and Zidovudine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Zidovudine
Dapsone 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
Hematologic toxicity (neutropenia)
Interaction Deep Dive
Concomitant administration of zidovudine with drugs like dapsone which are cytotoxic or suppress bone marrow function may increase the risk of hematologic toxicity3. Caution is warranted when dapsone and zidovudine are coadministered.
Why it happens (mechanism)
Unknown; possible additive or synergistic bone marrow suppression
Literature reports
2 reports — tap to read
a) One study compared aerosolized pentamidine (300 mg monthly) and dapsone (50 mg daily) for use as secondary prophylaxis of Pneumocystis pneumonia in a multicenter, randomized, unblinded study of 196 AIDS patients. During the study, 94% of the pentamidine group and 91% of the dapsone group received zidovudine for mean durations of 10 months and 9 months, respectively. The study was prematurely discontinued due to excessive mortality in the dapsone group. After following the subjects for an average of 13 months, 21% of the aerosolized pentamidine group were deceased, compared to 42% of the dapsone group. This suggests a negative interaction between dapsone and zidovudine in relation to survival. The authors suggest the possible interaction may be pharmacokinetic or secondary to dapsone inhibition of the effect of zidovudine on HIV replication 2. Increased mortality with dapsone in the Salmon-Ceron study could have been due to dapsone, lower CD4 cell counts in the dapsone group, or study design. With intent to treat analysis, death was ascribed to the randomized treatment but significantly more patients switched to pentamidine. Therefore, deaths may have been due to pentamidine but associated with dapsone in the analysis.
b) In a study of eight HIV positive subjects, no changes in pharmacokinetic parameters were observed when dapsone was given with zidovudine 1.
Common questions
Can I take Dapsone Topical and Zidovudine together?
Hematologic toxicity (neutropenia) Always confirm with your pharmacist or prescriber before making any change.
How serious is the Dapsone Topical and Zidovudine interaction?
It is rated major. Potentially serious — often needs a change or close 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 "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Dapsone Topical or Zidovudine 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 a safer alternative to one of these medications for me?
References (3)
- Lee BL, Safrin S, Makrides V, et al: Zidovudine, trimethoprim and dapsone pharmacokinetic interactions in patients with human immunodeficiency virus infection. Antimicrob Agents Chemother 1996; 40:1231-1236. DOI
- Salmon-Ceron D, Fontbonne A, Saba J, et al: Lower survival in AIDS patients receiving dapsone compared with aerosolized pentamidine for secondary prophylaxis of pneumocystis carinii pneumonia. J Infect Dis 1995; 172:656-664. DOI
- Product Information: Retrovir(R), zidovudine. Glaxo Wellcome Inc. Research Triangle Park, NC, 1996. DailyMed
Keep reading about Zidovudine
Keep reading about Dapsone Topical
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
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