Drug interactions
Cefalexin + Tobramycin
Severity: Moderate
Cefalexin 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
Cephalosporins given with aminoglycosides have been linked to additive nephrotoxicity in some reports, and tobramycin carries its own risk of kidney injury and ototoxicity. The added risk from cefalexin is modest but matters in patients with reduced renal function, older age or dehydration.
What this interaction means in plain words
Cefalexin 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.
Cefalexin belongs to Anti Bacterial; Tobramycin belongs to Anti Bacterial.
Why it happens
Additive nephrotoxic potential; tobramycin accumulates in proximal tubular cells and cefalexin may add to renal tubular stress.
What to do
Monitor serum creatinine and tobramycin trough levels, and assess hearing and balance if therapy is prolonged. Maintain hydration and adjust tobramycin dosing to renal function.
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 Cefalexin
- Amikacin + Cefalexin Moderate
- Avelumab + Cefalexin Moderate
- Balstilimab + Cefalexin Moderate
- Bcg vaccine live + Cefalexin Moderate
- Cefalexin + Cholera vaccine Moderate
- Cefalexin + Kanamycin Moderate
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 Cefalexin with Tobramycin?
MediHelp rates the interaction as moderate. Cefalexin 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. Cephalosporins given with aminoglycosides have been linked to additive nephrotoxicity in some reports, and tobramycin carries its own risk of kidney injury and ototoxicity. The added risk from cefalexin is modest but matters in patients with reduced renal function, older age or dehydration.
How serious is the interaction between Cefalexin 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 serum creatinine and tobramycin trough levels, and assess hearing and balance if therapy is prolonged. Maintain hydration and adjust tobramycin dosing to renal function.
What other medicines interact with Cefalexin?
MediHelp also lists interactions of Cefalexin with, for example, Amikacin, Avelumab, Balstilimab. The full list is on the Cefalexin page.
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