Does Acyclovir Interact With Valacyclovir?
4 CONTRAINDICATIONS Valacyclovir tablets are contraindicated in patients who have had a demonstrated clinically significant hypersensitivity reaction [e.g., anaphylaxis, severe cutaneous adverse reactions (SCARs)] to valacyclovir, acyclovir, or any component of the formulation [see Warnings and Precautions (5.4) , Adverse Reactions (6.3) ] .
Severity: Contraindicated
Severity basis: contraindications section (keywords: contraindicated). Combining Acyclovir (Antiviral (nucleoside analogue)) and Valacyclovir (Antiviral (nucleoside analogue)) is classified as a contraindicated interaction.
What to Do
This combination is contraindicated on the FDA label. Do not take these together unless your prescriber explicitly directs it.
From the FDA Label
4 CONTRAINDICATIONS Valacyclovir tablets are contraindicated in patients who have had a demonstrated clinically significant hypersensitivity reaction [e.g., anaphylaxis, severe cutaneous adverse reactions (SCARs)] to valacyclovir, acyclovir, or any component of the formulation [see Warnings and Precautions (5.4) , Adverse Reactions (6.3) ] .
Source: FDA structured product labeling (set_id 021ab9d0-7b75-40cf-afde-446942d64388).
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This information is educational — not medical advice.
This page is provided for general educational purposes and summarizes publicly available data from sources such as the U.S. Food & Drug Administration. It is not a substitute for the judgment of a licensed clinician and should not be used to start, stop, or change any medication. It may be incomplete or out of date, and individual circumstances vary. Always talk with your prescriber or pharmacist about your specific medications and health conditions. If you think you may have a medical emergency, call 911.