Drug Interaction Report

Piretanide and Gentamicin Topical: Interaction Details

Name: Piretanide and Gentamicin Topical Interaction
Creator: Dr. Brian Staiger, PharmD, BCPS

A pharmacist-reviewed analysis of the Piretanide and Gentamicin Topical interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Piretanide

No brand names on record

Gentamicin Topical

Garamycin®

Medically reviewed by

Dr. Brian Staiger, PharmD, BCPS

Updated Aug 8, 2026

Editorial policy · Data sources

Interaction severity

Moderate

Can be significant — usually manageable with monitoring.

Minor

Moderate

Major

Contraindicated

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.

Of 50 documented Piretanide interactions, 16 are rated moderate — including this one.

Onset

rapid

Evidence

theoretical

Severity

Moderate

What happens

Ototoxicity

Interaction Deep Dive

Although controversial, there is concern that loop diuretics may affect aminoglycoside pharmacokinetics resulting in aminoglycoside-induced ototoxicity²³. Concomitant IV therapy with piretanide and gentamicin was reported to increase renal clearance of gentamicin ¹.

Why it happens (mechanism)

Unknown

Literature reports

1 report — tap to read

a) It is suggested that piretanide can displace gentamicin from protein binding sites, thus increasing the amount of drug filtered at the glomerulus ¹.

Common questions

Can I take Piretanide and Gentamicin Topical together?

Ototoxicity Always confirm with your pharmacist or prescriber before making any change.

How serious is the Piretanide and Gentamicin Topical interaction?

It is rated moderate. Can be significant — usually manageable with 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 Piretanide or Gentamicin Topical 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 anything you'd monitor while I'm on both?

References (3)

Barber HE, Petersen J, & Whiting PH: The effects of either frusemide or piretanide on the pharmacokinetics of gentamicin. Br J Clin Pharmacol 1981; 11:113P-114P.
Brummett RE, Bendrick T, & Himes D: Comparative ototoxicity of bumetanide and furosemide when used in combination with kanamycin. J Clin Pharmacol 1981; 21:628-636. PubMed
Quick CA & Hoppe W: Permanent deafness associated with furosemide administration. Ann Otol Rhinol Laryngol 1975; 84:94-101. DOI

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Piretanide

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Gentamicin Topical

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About our interaction database: depth, not breadth

HelloPharmacist doesn't license one of the big commercial interaction databases, so what you'll find here is not a complete list of every known drug interaction. Instead, each entry is researched, analyzed, and written up individually — documented from the published literature, reviewed by a pharmacist, and cited so you can check every source yourself.

If a combination isn't listed here, it means we haven't documented it yet — never that it's safe. For screening a full medication list, we recommend pairing this site with a comprehensive tool like the Drugs.com Interaction Checker and, most importantly, a review by your own pharmacist. For a deep, plain-English, fully sourced explanation of a specific documented interaction — that's exactly what we built this for.

This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.