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acyclovir vs emtricitabine/tenofovir

Side-by-side comparison of acyclovir and emtricitabine/tenofovir Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

minor Known Drug Interaction

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) ] .

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

Drug Class
acyclovir Antiviral (Nucleoside Analog)
emtricitabine/tenofovir NRTI Combination (HIV PrEP)
Type
acyclovir Prescription
emtricitabine/tenofovir Prescription
Summary
acyclovir

Acyclovir is an antiviral medicine. It is used to treat infections caused by certain viruses.

emtricitabine/tenofovir

Truvada is a medicine that contains two drugs, emtricitabine and tenofovir. It is used to treat HIV-1 infection and to prevent getting HIV-1.

What It Treats
acyclovir

Acyclovir is used to treat shingles, which is caused by herpes zoster. It also treats genital herpes, both the first time you have it and when it comes back. Acyclovir can also treat chickenpox.

emtricitabine/tenofovir

Truvada is used to treat HIV-1 infection in adults and children who weigh at least 37 pounds. It must be used with other HIV medicines. Truvada can also be used to help prevent getting HIV-1 in adults who are at high risk. When used for prevention, it is called PrEP (pre-exposure prophylaxis) and should be used with safer sex practices.

How It Works
acyclovir

Acyclovir stops the virus from growing and spreading. It does this by interfering with the virus's ability to make copies of itself. This helps your body fight off the infection.

emtricitabine/tenofovir

Truvada contains two medicines that block HIV-1 reverse transcriptase. This enzyme is needed for HIV to multiply. By blocking this enzyme, Truvada helps to lower the amount of HIV in your body and prevent HIV infection.

Common Side Effects
acyclovir
  • Malaise (feeling unwell)
  • Nausea
  • Diarrhea
emtricitabine/tenofovir
  • Diarrhea
  • Nausea
  • Tiredness
  • Headache
  • Dizziness
FAERS Reports
acyclovir
  • Tiredness 7,612
  • Diarrhea 7,064
  • Using the medicine for something it's not approved for 5,797
  • Lung infection 5,474
  • Feeling sick to your stomach 5,330
emtricitabine/tenofovir
  • Drug Interaction 655
  • Foetal Exposure During Pregnancy 621
  • Anxiety 432
  • Drug Resistance 431
  • Virologic Failure 402
Serious Warnings
acyclovir

Acyclovir can cause nervous system problems, especially in older adults or people with kidney problems. Tell your doctor if you have kidney problems before taking this medicine.

emtricitabine/tenofovir

Truvada can cause serious side effects, including lactic acidosis and severe liver problems. Tell your doctor right away if you have any symptoms of these problems. If you have hepatitis B and stop taking Truvada, your hepatitis B may get worse. Your doctor will need to monitor you closely for several months if you stop taking Truvada. If you are using Truvada to prevent HIV, you must be tested to be sure you do not have HIV. If you take Truvada when you have HIV, the HIV virus can become resistant to the medicine.

Pregnancy
acyclovir

Tell your doctor if you are pregnant or plan to become pregnant. It is not known if acyclovir will harm an unborn baby. Talk to your doctor about the risks and benefits of taking acyclovir while breastfeeding.

emtricitabine/tenofovir

Tell your doctor if you are pregnant or plan to become pregnant. Truvada should be used during pregnancy only if clearly needed. If you are infected with HIV, you should not breastfeed because you could pass HIV to your baby.

Also Compare — Nearby Drugs

How to Read This acyclovir vs emtricitabine/tenofovir Comparison

acyclovir is classified in the Antiviral (Nucleoside Analog) drug class, while emtricitabine/tenofovir sits within the NRTI Combination (HIV PrEP) class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.

Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, acyclovir has 31,277 submissions while emtricitabine/tenofovir has 2,541. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known minor interaction flagged in FDA labeling, attributed to 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.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.

A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between acyclovir and emtricitabine/tenofovir — always consult your physician or pharmacist first.

Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.