Drug interactions
Dapsone + Isosorbide dinitrate
Severity: Moderate
Dapsone and Isosorbide dinitrate: 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
Isosorbide dinitrate and dapsone can both cause methemoglobinemia, so the combination may increase methemoglobin levels. Topical dapsone is poorly absorbed, so the risk is mainly with oral dapsone.
What this interaction means in plain words
Dapsone and Isosorbide dinitrate 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; Isosorbide dinitrate belongs to Cardiovascular.
Why it happens
Additive oxidation of hemoglobin to methemoglobin from nitrate-derived nitrite and dapsone hydroxylamine metabolites.
What to do
Monitor for cyanosis, dyspnea and low oxygen saturation; measure methemoglobin if these occur and give methylene blue if symptomatic.
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 Isosorbide dinitrate
- Avanafil + Isosorbide dinitrate Contraindicated
- Isosorbide dinitrate + Riociguat Contraindicated
- Isosorbide dinitrate + Sildenafil Contraindicated
- Isosorbide dinitrate + Tadalafil Contraindicated
- Isosorbide dinitrate + Vardenafil Contraindicated
- Ergotamine + Isosorbide dinitrate Major
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
Frequently asked questions
Can I take Dapsone with Isosorbide dinitrate?
MediHelp rates the interaction as moderate. Dapsone and Isosorbide dinitrate 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. Isosorbide dinitrate and dapsone can both cause methemoglobinemia, so the combination may increase methemoglobin levels. Topical dapsone is poorly absorbed, so the risk is mainly with oral dapsone.
How serious is the interaction between Dapsone and Isosorbide dinitrate?
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 for cyanosis, dyspnea and low oxygen saturation; measure methemoglobin if these occur and give methylene blue if symptomatic.
What other medicines interact with Isosorbide dinitrate?
MediHelp also lists interactions of Isosorbide dinitrate with, for example, Avanafil, Riociguat, Sildenafil. The full list is on the Isosorbide dinitrate page.
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