Drug interactions
Digoxin + Tobramycin
Severity: Moderate
Digoxin and Tobramycin: 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
Oral tobramycin may suppress gut bacteria that inactivate digoxin (Eubacterium lentum) in some patients, raising digoxin absorption and serum levels. Systemic tobramycin has no such effect, but electrolyte wasting can independently promote digoxin toxicity.
What this interaction means in plain words
Digoxin and Tobramycin 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.
Digoxin belongs to Cardiovascular; Tobramycin belongs to Anti Bacterial.
Why it happens
Reduced intestinal bacterial metabolism of digoxin increases its bioavailability.
What to do
Monitor digoxin levels and signs of toxicity when oral tobramycin is used; also monitor potassium and magnesium with parenteral use.
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 Tobramycin
- Cidofovir + Tobramycin Contraindicated
- Adefovir + Tobramycin Major
- Amikacin + Tobramycin Major
- Amphotericin b deoxycholate + Tobramycin Major
- Amphotericin b + Tobramycin Major
- Atracurium + Tobramycin Major
Other interactions of Digoxin
- Digoxin + Lily of the valley Contraindicated
- Digoxin + Squill Contraindicated
- Adagrasib + Digoxin Major
- Amiodarone + Digoxin Major
- Amlodipine-hydrochlorothiazide-valsartan + Digoxin Major
- Amphotericin b deoxycholate + Digoxin Major
Frequently asked questions
Can I take Digoxin with Tobramycin?
MediHelp rates the interaction as moderate. Digoxin and Tobramycin 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. Oral tobramycin may suppress gut bacteria that inactivate digoxin (Eubacterium lentum) in some patients, raising digoxin absorption and serum levels. Systemic tobramycin has no such effect, but electrolyte wasting can independently promote digoxin toxicity.
How serious is the interaction between Digoxin and Tobramycin?
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 digoxin levels and signs of toxicity when oral tobramycin is used; also monitor potassium and magnesium with parenteral use.
What other medicines interact with Tobramycin?
MediHelp also lists interactions of Tobramycin with, for example, Cidofovir, Adefovir, Amikacin. The full list is on the Tobramycin page.
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