Gentamicin Topical and Lysine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Gentamicin Topical
Lysine
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased risk of nephrotoxicity
Interaction Deep Dive
Lysine increased the nephrotoxicity of aminoglycosides in rats1. It is unknown if the same effect will occur in humans, but caution is advised if both must be used together.
Why it happens (mechanism)
Glomerular injury
Literature reports
1 report — tap to read
a) The combination of intravenous lysine and single large doses of aminoglycosides induced additive renal toxicity in rats. Greater reductions in glomerular filtration rate and renal blood flow occurred with the combination over that seen with either agent alone. Medullary casts and tubular necrosis were observed with the combination to a greater extent than with either agent alone 1.
Common questions
Can I take Gentamicin Topical and Lysine together?
Increased risk of nephrotoxicity Always confirm with your pharmacist or prescriber before making any change.
How serious is the Gentamicin Topical and Lysine interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Gentamicin Topical or Lysine need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Malis CD, Racusen LC, Solez K, et al: Nephrotoxicity of lysine and of a single dose of aminoglycoside in rats given lysine. J Lab Clin Med 1984; 103(5):660-676.
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Keep reading about Lysine
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