PlainMeds provides educational information only. This is not medical advice. Always consult your doctor or pharmacist.

Emtricitabine/Tenofovir and Acyclovir Interaction

Drug interaction information between Emtricitabine/Tenofovir and Acyclovir.

Emtricitabine/Tenofovir and Acyclovir have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Emtricitabine/Tenofovir and Acyclovir. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.

Drug A

Emtricitabine/Tenofovir

NRTI Combination (HIV PrEP)

Drug B

Acyclovir

Antiviral (Nucleoside Analog)

How They Interact

These medicines are cleared from the body using the same pathway in the kidneys, which can lead to higher levels of the drugs in your system.

What To Do

Your doctor should check your kidney health regularly to ensure the medications are being cleared safely from your body.

FDA Label Information

Some examples include, but are not limited to, acyclovir, adefovir dipivoxil, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides (e.g., gentamicin), and high-dose or multiple NSAIDs [see Warnings and Precautions (5.3) ] .

Frequently Asked Questions

Can I take Emtricitabine/Tenofovir and Acyclovir together?

This is a minor interaction. Your doctor should check your kidney health regularly to ensure the medications are being cleared safely from your body.

How serious is the interaction between Emtricitabine/Tenofovir and Acyclovir?

This interaction is classified as "minor" severity by the FDA. Minor interactions are unlikely to cause significant problems but should still be mentioned to your healthcare provider.

Why do Emtricitabine/Tenofovir and Acyclovir interact?

These medicines are cleared from the body using the same pathway in the kidneys, which can lead to higher levels of the drugs in your system.

Understanding the Emtricitabine/Tenofovir and Acyclovir Interaction

FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Emtricitabine/Tenofovir belongs to the NRTI Combination (HIV PrEP) class and Acyclovir belongs to the Antiviral (Nucleoside Analog) class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: These medicines are cleared from the body using the same pathway in the kidneys, which can lead to higher levels of the drugs in your system. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.

Context around a specific patient determines real-world impact. Emtricitabine/Tenofovir has 9 total documented interactions on file in this dataset, and Acyclovir has 7. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Your doctor should check your kidney health regularly to ensure the medications are being cleared safely from your body. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.

An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Emtricitabine/Tenofovir or Acyclovir based on a web page, speak with your prescriber or pharmacist before making any change.

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.