acyclovir vs efavirenz/emtricitabine/tenofovir
Side-by-side comparison of acyclovir and efavirenz/emtricitabine/tenofovir Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
Zovirax
Acyclovir is an antiviral medicine. It is used to treat infections caused by certain viruses.
Efavirenz is a drug used to treat HIV-1 infection. It belongs to a class of drugs called non-nucleoside reverse transcriptase inhibitors (NNRTI).
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.
Efavirenz is used to treat HIV-1, the virus that causes AIDS. It helps to lower the amount of virus in your body. This medicine must be used with other HIV medicines.
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.
Efavirenz blocks an enzyme called reverse transcriptase. HIV needs this enzyme to make copies of itself. By blocking it, efavirenz helps to slow down the spread of HIV in your body.
- • Malaise (feeling unwell)
- • Nausea
- • Diarrhea
- • Rash
- • Dizziness
- • Nausea
- • Headache
- • Fatigue
- 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
- Virologic Failure 952
- Drug Interaction 748
- Drug Resistance 735
- Viral Mutation Identified 674
- Pathogen Resistance 623
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.
Efavirenz can cause serious side effects, including psychiatric problems like depression or suicidal thoughts. Tell your doctor right away if you have any of these symptoms. Efavirenz can also harm your liver. Your doctor should check your liver function before and during treatment. Do not take efavirenz by itself.
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.
Efavirenz can harm your unborn baby, especially during the first 3 months of pregnancy. Talk to your doctor about using birth control while taking this medicine. Breastfeeding is not recommended while taking efavirenz.
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How to Read This acyclovir vs efavirenz/emtricitabine/tenofovir Comparison
acyclovir is classified in the Antiviral (Nucleoside Analog) drug class, while efavirenz/emtricitabine/tenofovir sits within the NNRTI / NRTI Combination 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 efavirenz/emtricitabine/tenofovir has 3,732. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. No direct interaction between these two drugs is listed in our FDA-derived dataset, though co-prescription still warrants pharmacist review. 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 efavirenz/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.