Drug interactions
Cefalexin + Gentamicin
Severity: Moderate
Cefalexin and Gentamicin: 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
Gentamicin is nephrotoxic and ototoxic, and cephalosporins have been reported to add to renal injury in some patients. Cefalexin is rarely nephrotoxic, so the effect is modest. Risk rises with renal impairment, advanced age, and dehydration.
What this interaction means in plain words
Cefalexin and Gentamicin 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; Gentamicin belongs to Anti Bacterial.
Why it happens
Possible additive nephrotoxicity; mechanism poorly defined.
What to do
Monitor serum creatinine and gentamicin levels during therapy. Maintain hydration and avoid additional nephrotoxins.
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 Gentamicin
- Cidofovir + Gentamicin Contraindicated
- Adefovir + Gentamicin Major
- Amikacin + Gentamicin Major
- Amlodipine-hydrochlorothiazide-valsartan + Gentamicin Major
- Amphotericin b deoxycholate + Gentamicin Major
- Amphotericin b + Gentamicin Major
Frequently asked questions
Can I take Cefalexin with Gentamicin?
MediHelp rates the interaction as moderate. Cefalexin and Gentamicin 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. Gentamicin is nephrotoxic and ototoxic, and cephalosporins have been reported to add to renal injury in some patients. Cefalexin is rarely nephrotoxic, so the effect is modest. Risk rises with renal impairment, advanced age, and dehydration.
How serious is the interaction between Cefalexin and Gentamicin?
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 gentamicin levels during therapy. Maintain hydration and avoid additional nephrotoxins.
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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