Emtricitabine/Tenofovir and Tenofovir Disoproxil Interaction
Drug interaction information between Emtricitabine/Tenofovir and Tenofovir Disoproxil.
Emtricitabine/Tenofovir and Tenofovir Disoproxil have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Emtricitabine/Tenofovir and Tenofovir Disoproxil. 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.
How They Interact
These medications contain the same active ingredient. Taking both at once can lead to having too much of the medicine in your body.
What To Do
You should not take these two medications together because they are redundant.
FDA Label Information
Drug interaction trials have been conducted with emtricitabine and tenofovir disoproxil fumarate, the components of TRUVADA. This section describes clinically relevant drug interactions observed with emtricitabine and tenofovir disoproxil fumarate [see Clinical Pharmacology (12.3) ] . Didanosine: Tenofovir disoproxil fumarate increases didanosine concentrations.
Emtricitabine/Tenofovir Also Interacts With
- Valacyclovir minor
- Acyclovir minor
- Gentamicin minor
- Darunavir minor
- Ledipasvir/Sofosbuvir minor
Tenofovir Disoproxil Also Interacts With
- Itraconazole moderate
- Valacyclovir minor
- Acyclovir minor
- Gentamicin minor
- Darunavir minor
Frequently Asked Questions
Can I take Emtricitabine/Tenofovir and Tenofovir Disoproxil together?
This is a minor interaction. You should not take these two medications together because they are redundant.
How serious is the interaction between Emtricitabine/Tenofovir and Tenofovir Disoproxil?
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 Tenofovir Disoproxil interact?
These medications contain the same active ingredient. Taking both at once can lead to having too much of the medicine in your body.
Understanding the Emtricitabine/Tenofovir and Tenofovir Disoproxil 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 Tenofovir Disoproxil belongs to the Nucleotide Reverse Transcriptase Inhibitor class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: These medications contain the same active ingredient. 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 Tenofovir Disoproxil has 14. 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: You should not take these two medications together because they are redundant. 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 Tenofovir Disoproxil 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.
Read our methodology - how this data is sourced, computed, and verified.