Drug interactions
Gentamicin + Tobramycin
Severity: Major
Gentamicin and Tobramycin: major 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
Using two aminoglycosides together adds no therapeutic benefit and substantially increases the risk of nephrotoxicity, ototoxicity and neuromuscular blockade. Both accumulate in renal tubular and inner ear cells.
What this interaction means in plain words
Gentamicin and Tobramycin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Gentamicin belongs to Anti Bacterial; Tobramycin belongs to Anti Bacterial.
Why it happens
Additive proximal tubular and cochlear/vestibular hair cell toxicity from two drugs of the same class.
What to do
Avoid concurrent use of two aminoglycosides and choose a single agent. If one was recently used, monitor renal function and drug levels and assess hearing and balance.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Gentamicin
- Cidofovir + Gentamicin Contraindicated
- Adefovir + Gentamicin Major
- Amikacin + Gentamicin Major
- Amlodipine-hydrochlorothiazide-valsartan + Gentamicin Major
- Amphotericin b deoxycholate + Gentamicin Major
- Amphotericin b + Gentamicin Major
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
Frequently asked questions
Can I take Gentamicin with Tobramycin?
MediHelp rates the interaction as major. Gentamicin and Tobramycin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Using two aminoglycosides together adds no therapeutic benefit and substantially increases the risk of nephrotoxicity, ototoxicity and neuromuscular blockade. Both accumulate in renal tubular and inner ear cells.
How serious is the interaction between Gentamicin and Tobramycin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concurrent use of two aminoglycosides and choose a single agent. If one was recently used, monitor renal function and drug levels and assess hearing and balance.
What other medicines interact with Gentamicin?
MediHelp also lists interactions of Gentamicin with, for example, Cidofovir, Adefovir, Amikacin. The full list is on the Gentamicin page.
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