Drug interactions
acyclovir + vancomycin
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.
Overview
Additive nephrotoxicity risk leading to acute kidney injury; reduced renal function can elevate vancomycin and acyclovir exposures and increase risk of acyclovir neurotoxicity.
Mechanism of action
Pharmacodynamic: additive nephrotoxicity (acyclovir crystal-induced obstructive nephropathy; vancomycin tubular injury). Pharmacokinetic: both renally eliminated—AKI decreases clearance, raising drug levels.
Clinical management
Avoid combination if feasible. If needed, ensure adequate hydration; use the lowest effective doses; infuse IV acyclovir over ≥1 hour; adjust both drugs for renal function; monitor serum creatinine and urine output at baseline and at least every 48–72 hours; monitor vancomycin AUC/troughs and adjust dosing; watch for neurotoxicity (confusion, tremor) and discontinue/switch if AKI develops.
Drug reference
References
- Acyclovir (Zovirax) Prescribing Information — FDA Label
- Vancomycin Prescribing Information — FDA Label
- Acyclovir: Drug Information — UpToDate
- Vancomycin: Drug Information — UpToDate
- Acyclovir + Nephrotoxic Agents (including Vancomycin) — Drug Interactions — Lexicomp
Frequently asked questions
Can I take acyclovir with vancomycin?
The interaction is rated: Moderate. Additive nephrotoxicity risk leading to acute kidney injury; reduced renal function can elevate vancomycin and acyclovir exposures and increase risk of acyclovir neurotoxicity.
How serious is the interaction between acyclovir and vancomycin?
The interaction is rated: Moderate. Evidence level: Moderate.
How is the interaction between acyclovir and vancomycin managed?
Avoid combination if feasible. If needed, ensure adequate hydration; use the lowest effective doses; infuse IV acyclovir over ≥1 hour; adjust both drugs for renal function; monitor serum creatinine and urine output at baseline and at least every 48–72 hours; monitor vancomycin AUC/troughs and adjust dosing; watch for neurotoxicity (confusion, tremor) and discontinue/switch if AKI develops.
Why do acyclovir and vancomycin interact?
Pharmacodynamic: additive nephrotoxicity (acyclovir crystal-induced obstructive nephropathy; vancomycin tubular injury). Pharmacokinetic: both renally eliminated—AKI decreases clearance, raising drug levels.
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