Drug interactions
Isosorbide dinitrate + Tetracaine
Severity: Moderate
Isosorbide dinitrate and Tetracaine: 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
Both nitrates and local anesthetics such as tetracaine can oxidize hemoglobin to methemoglobin. Using them together may add to methemoglobin formation and reduce oxygen delivery, causing cyanosis, dyspnea or headache. Risk is higher with extensive mucosal application, high doses, infants or underlying methemoglobinemia risk.
What this interaction means in plain words
Isosorbide dinitrate and Tetracaine 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 belongs to Cardiovascular; Tetracaine belongs to Central Nervous System.
Why it happens
Additive oxidation of hemoglobin iron to the ferric state by both drugs, producing methemoglobin.
What to do
Limit the dose and area of tetracaine application and watch for cyanosis, hypoxia unresponsive to oxygen, or dyspnea. If methemoglobinemia is suspected, check co-oximetry and treat with methylene blue.
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 Tetracaine
- Chloroquine + Tetracaine Moderate
- Dapsone + Tetracaine Moderate
- Isosorbide mononitrate + Tetracaine Moderate
- Nitrofurantoin + Tetracaine Moderate
- Nitroglycerin + Tetracaine Moderate
- Paracetamol + Tetracaine Moderate
Frequently asked questions
Can I take Isosorbide dinitrate with Tetracaine?
MediHelp rates the interaction as moderate. Isosorbide dinitrate and Tetracaine 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. Both nitrates and local anesthetics such as tetracaine can oxidize hemoglobin to methemoglobin. Using them together may add to methemoglobin formation and reduce oxygen delivery, causing cyanosis, dyspnea or headache. Risk is higher with extensive mucosal application, high doses, infants or underlying methemoglobinemia risk.
How serious is the interaction between Isosorbide dinitrate and Tetracaine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Limit the dose and area of tetracaine application and watch for cyanosis, hypoxia unresponsive to oxygen, or dyspnea. If methemoglobinemia is suspected, check co-oximetry and treat with methylene blue.
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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