Drug interactions
Dapsone + Ketoconazole
Severity: Moderate
Dapsone and Ketoconazole: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Ketoconazole is a strong CYP3A4 inhibitor and may increase dapsone concentrations. This raises the potential for dose-related haemolysis and methaemoglobinaemia.
What this interaction means in plain words
Dapsone and Ketoconazole can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Dapsone belongs to Anti Bacterial; Ketoconazole belongs to Anti Fungals.
Why it happens
Inhibition of CYP3A4-mediated dapsone metabolism by ketoconazole.
What to do
Monitor full blood count and methaemoglobin levels and consider reducing dapsone dose if toxicity appears.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Dapsone
- Bcg vaccine live + Dapsone Major
- Dapsone + Primaquine Major
- Apalutamide + Dapsone Moderate
- Belzutifan + Dapsone Moderate
- Bosentan + Dapsone Moderate
- Bupivacaine implant + Dapsone Moderate
Other interactions of Ketoconazole
- Alfuzosin + Ketoconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Avanafil + Ketoconazole Contraindicated
- Conivaptan + Ketoconazole Contraindicated
- Dihydroergotamine intranasal + Ketoconazole Contraindicated
- Dihydroergotamine + Ketoconazole Contraindicated
Frequently asked questions
Can I take Dapsone with Ketoconazole?
MediHelp rates the interaction as moderate. Dapsone and Ketoconazole can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Ketoconazole is a strong CYP3A4 inhibitor and may increase dapsone concentrations. This raises the potential for dose-related haemolysis and methaemoglobinaemia.
How serious is the interaction between Dapsone and Ketoconazole?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor full blood count and methaemoglobin levels and consider reducing dapsone dose if toxicity appears.
What other medicines interact with Dapsone?
MediHelp also lists interactions of Dapsone with, for example, Bcg vaccine live, Primaquine, Apalutamide. The full list is on the Dapsone page.
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