Gentamicin Injection and Vancomycin: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Vancomycin
Gentamicin Injection
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
An increased risk of ototoxicity and an increased risk if nephrotoxicity
Interaction Deep Dive
Concomitant use of vancomycin and aminoglycosides may increase the risk of ototoxicity. Ototoxicity has occurred in patients administered vancomycin IV or orally. It may be transient or permanent. Monitor for signs and symptoms of ototoxicity during oral or IV therapy with vancomycin. Discontinue vancomycin if ototoxicity occurs. Serial tests of auditory function may be helpful in order to minimize the risk of ototoxicity12. Although there is some controversy, the best evidence suggests that concurrent use of vancomycin and an aminoglycoside antibiotic is associated with a higher incidence of nephrotoxicity than either agent alone 345.
Why it happens (mechanism)
Additive nephrotoxic effects; additive ototoxicity
Literature reports
1 report — tap to read
a) Although there is some controversy, the best evidence suggests that concurrent use of vancomycin and an aminoglycoside antibiotic is associated with a higher incidence of nephrotoxicity than either agent alone 345. One prospective study of 136 elderly patients reported a 24% incidence of nephrotoxicity (increase in serum creatinine of at least 0.5 mg/dL) with the combination compared to vancomycin alone (19%) or aminoglycoside alone (12%). A follow-up meta-analysis of 8 studies of this interaction found that the incidence of nephrotoxicity with the combination was 13% greater than vancomycin alone (p=0.01) and 4% greater than aminoglycoside alone (p=0.05). Risk factors which have been reported include creatinine clearance less than 40 mL/min, age greater than 65, and gentamicin/tobramycin trough serum levels greater than 1.5 mcg/mL 3.
Common questions
Can I take Gentamicin Injection and Vancomycin together?
An increased risk of ototoxicity and an increased risk if nephrotoxicity Always confirm with your pharmacist or prescriber before making any change.
How serious is the Gentamicin Injection and Vancomycin interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
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 Injection or Vancomycin 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 (5)
- Product Information: VANCOMYCIN HYDROCHLORIDE intravenous injection, vancomycin hydrochloride intravenous injection. Hikma Pharmaceuticals USA Inc. (per Dailymed), Berkeley Heights, NJ, 2024. DailyMed
- Product Information: TYZAVAN intravenous injection, vancomycin hydrochloride intravenous injection. Hikma Pharmaceuticals USA Inc (per FDA), Berkeley Heights, NJ, 2025. DailyMed
- Goetz MB & Sayers J: Nephrotoxicity of vancomycin and aminoglycoside therapy separately and in combination. J Antimicrob Chemother 1993; 32:325-334. PubMed
- Pauly DJ, Musa DM, Lestico MR, et al: Risk of nephrotoxicity with combination vancomycin-aminoglycoside antibiotic therapy. Pharmacotherapy 1990; 10:378-382. DOI
- Downs NJ, Neihart RE, Dolezal JM, et al: Mild nephrotoxicity associated with vancomycin use. Arch Intern Med 1989; 149:1777-1781. DOI
Keep reading about Vancomycin
Keep reading about Gentamicin Injection
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