Drug interactions
Nitrofurantoin + Tetracaine
Severity: Moderate
Nitrofurantoin 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 drugs have been associated with methemoglobinemia. Used together, especially with significant systemic exposure to tetracaine, the risk may be additive. Patients may develop cyanosis, dyspnea, or low pulse oximetry readings not responding to oxygen.
What this interaction means in plain words
Nitrofurantoin 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.
Nitrofurantoin belongs to Anti Bacterial; Tetracaine belongs to Central Nervous System.
Why it happens
Additive oxidant stress on hemoglobin leading to methemoglobin formation.
What to do
Monitor for signs of methemoglobinemia such as cyanosis and unexplained hypoxia. Treat with methylene blue if symptomatic, and take extra care in G6PD deficiency, infants, or with large mucosal tetracaine doses.
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 Nitrofurantoin
Other interactions of Tetracaine
- Chloroquine + Tetracaine Moderate
- Dapsone + Tetracaine Moderate
- Isosorbide dinitrate + Tetracaine Moderate
- Isosorbide mononitrate + Tetracaine Moderate
- Nitroglycerin + Tetracaine Moderate
- Paracetamol + Tetracaine Moderate
Frequently asked questions
Can I take Nitrofurantoin with Tetracaine?
MediHelp rates the interaction as moderate. Nitrofurantoin 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 drugs have been associated with methemoglobinemia. Used together, especially with significant systemic exposure to tetracaine, the risk may be additive. Patients may develop cyanosis, dyspnea, or low pulse oximetry readings not responding to oxygen.
How serious is the interaction between Nitrofurantoin 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: Monitor for signs of methemoglobinemia such as cyanosis and unexplained hypoxia. Treat with methylene blue if symptomatic, and take extra care in G6PD deficiency, infants, or with large mucosal tetracaine doses.
What other medicines interact with Nitrofurantoin?
MediHelp also lists interactions of Nitrofurantoin with, for example, Pexidartinib, Pretomanid, Aluminum hydroxide. The full list is on the Nitrofurantoin page.
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