acyclovir vs remdesivir
Side-by-side comparison of acyclovir and remdesivir Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
Zovirax
Veklury
Acyclovir is an antiviral medicine. It is used to treat infections caused by certain viruses.
Remdesivir (Veklury) is an antiviral medicine used to treat COVID-19. It helps stop the virus from multiplying in your body.
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.
Remdesivir is used to treat COVID-19 in adults and children who weigh at least 3.3 pounds. It can be used whether you are in the hospital or not. It is for people who have mild-to-moderate COVID-19 and are at high risk of getting very sick, needing to go to the hospital, or dying.
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.
Remdesivir is a type of medicine called a nucleotide analog RNA polymerase inhibitor. This means it blocks the virus from making copies of itself. By stopping the virus from multiplying, it can help you recover from COVID-19.
- • Malaise (feeling unwell)
- • Nausea
- • Diarrhea
- • Nausea
- • Increased ALT (a liver enzyme)
- • Increased AST (a liver enzyme)
- 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
- Off Label Use 2,208
- Alanine Aminotransferase Increased 933
- Covid-19 896
- Drug Ineffective 762
- Death 751
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.
Remdesivir can cause serious side effects, including allergic reactions and liver problems. Allergic reactions can happen during or after the infusion. Tell your doctor right away if you have signs like low or high blood pressure, fast or slow heart rate, fever, trouble breathing, wheezing, swelling, rash, nausea, sweating, or shaking. Your doctor will do blood tests to check your liver before and during treatment. Tell your doctor if you have any signs of liver problems like yellowing of the skin or eyes.
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.
If you are pregnant, talk to your doctor about the risks and benefits of taking remdesivir. Studies have not shown an increased risk of birth defects or miscarriage when taken during the second or third trimester. It is not known if it is safe to take during the first trimester.
Also Compare — Nearby Drugs
Compare acyclovir with
How to Read This acyclovir vs remdesivir Comparison
acyclovir is classified in the Antiviral (Nucleoside Analog) drug class, while remdesivir sits within the Nucleotide Analog (Antiviral) 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 remdesivir has 5,550. 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 remdesivir — 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.