Drug interactions
Dapsone + Nitroglycerin
Severity: Moderate
Dapsone and Nitroglycerin: 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
Nitroglycerin and dapsone can each cause methemoglobinemia, so together they may raise methemoglobin levels more than either alone. The risk is higher with oral dapsone or high-dose intravenous nitroglycerin and is small with topical dapsone.
What this interaction means in plain words
Dapsone and Nitroglycerin 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; Nitroglycerin belongs to Cardiovascular.
Why it happens
Additive oxidation of hemoglobin to methemoglobin by nitrite-generating nitroglycerin metabolism and dapsone hydroxylamine metabolites.
What to do
Watch for cyanosis, dyspnea or a discrepancy between pulse oximetry and clinical status, and measure methemoglobin if suspected; give methylene blue for symptomatic cases.
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 Nitroglycerin
- Avanafil + Nitroglycerin Contraindicated
- Nitroglycerin + Riociguat Contraindicated
- Nitroglycerin + Sildenafil Contraindicated
- Nitroglycerin + Tadalafil Contraindicated
- Nitroglycerin + Vardenafil Contraindicated
- Dihydroergotamine intranasal + Nitroglycerin 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 Nitroglycerin?
MediHelp rates the interaction as moderate. Dapsone and Nitroglycerin 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. Nitroglycerin and dapsone can each cause methemoglobinemia, so together they may raise methemoglobin levels more than either alone. The risk is higher with oral dapsone or high-dose intravenous nitroglycerin and is small with topical dapsone.
How serious is the interaction between Dapsone and Nitroglycerin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Watch for cyanosis, dyspnea or a discrepancy between pulse oximetry and clinical status, and measure methemoglobin if suspected; give methylene blue for symptomatic cases.
What other medicines interact with Nitroglycerin?
MediHelp also lists interactions of Nitroglycerin with, for example, Avanafil, Riociguat, Sildenafil. The full list is on the Nitroglycerin page.
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