Antivirals Zovirax (acyclovir) vs. Valtrex (valacyclovir)

Antivirals are medications designed to fight viruses. Most antivirals target specific viruses. The antivirals acyclovir (generic for Zovirax and Sitavig) and valacyclovir (generic for Valtrex) are used to treat or prevent infections caused by the herpes simplex, herpes zoster, and varicella-zoster viruses.

Although both drugs target the same viruses, there are a few differences between them. Read on for a comparison of the two drugs.

How Do Acyclovir and Valacyclovir Work?

Valacyclovir is a prodrug of acyclovir. This means that after it is in your body, valacyclovir turns into acyclovir. Consequently, both drugs work in similar ways. Acyclovir binds to virus DNA and prevents it from making more DNA and reproducing.

Valacyclovir is available in tablets.

Acyclovir is available in:

• Capsules
• Cream
• Ointment
• Oral suspension
• Solution for injection
• Sublingual tablets
• Tablets

What Conditions Do Acyclovir and Valacyclovir Treat?

Acyclovir and valacyclovir are both used for the following indications:

• Treatment of chickenpox
• Prevention and treatment of cold sores
• Prevention and treatment of genital herpes
• Treatment of shingles

Additionally, the acyclovir injection can be used to treat:

• Herpes of the brain (herpes simplex encephalitis) in children and adults
• Herpes infection in newborn babies

Acyclovir and valacyclovir do not cure cold sores, herpes, or shingles. However, they relieve the symptoms of the outbreaks and help the lesions heal faster.

How Do You Take Acyclovir and Valacyclovir?

The dose of both acyclovir and valacyclovir varies depending on your body weight and the condition you are treating. Your healthcare provider will decide what dose is best for you. Oral valacyclovir is more readily available in your body than oral acyclovir. It can be taken once or twice a day, while acyclovir is generally taken up to five times a day.

If you have kidney disease, talk to your doctor about adjusting your acyclovir or valacyclovir dose.

Acyclovir works better if you take it as soon as possible after experiencing symptoms of herpes infection, chickenpox, or shingles. You can take acyclovir with or without meals, but it is best to take the medication with a full glass of water.

You should take valacyclovir within 24 to 48 hours of the onset of symptoms. You can take this medication with or without food. To protect your kidneys, drink extra liquids while you are taking valacyclovir.

What Are the Side Effects of Acyclovir and Valacyclovir?

The most common side effects seen with acyclovir include:

• Diarrhea
• Inflammation or irritation at the injection site
• Nausea
• Vomiting

Common side effects seen with valacyclovir include:

• Difficulty concentrating
• Difficulty sleeping
• Discouraged feeling
• Headache
• Irritability
• Loss of appetite
• Nausea
• Sadness
• Stomach pain
• Tiredness

Can I Take Acyclovir or Valacyclovir if I Am Pregnant or Breastfeeding?

Both acyclovir and valacyclovir are classified as pregnancy category B. This means that the medication is generally safe to use during pregnancy if it is clearly needed. Other drugs classified as pregnancy category B include prenatal vitamins and acetaminophen (Tylenol).

Acyclovir and valacyclovir can pass into breastmilk to some degree. The manufacturers of both drugs recommend using these medications cautiously if you are nursing.

Which Is Better — Acyclovir or Valacyclovir?

The choice between acyclovir and valacyclovir depends on a few factors, including side effects and how often you take the medication. Acyclovir and valacyclovir are equally effective. However, you are more likely to follow your medication regimen if you only need to take medicine once or twice a day versus five times per day.

On the other hand, acyclovir is available as an oral suspension and tablets that dissolve under the tongue. These formulations are easier to use with children or people who have trouble swallowing pills.

Acyclovir is also available as a cream and an ointment. These topical formulations may be applied directly to cold sores or herpes lesions.

How Much Do Acyclovir and Valacyclovir Cost?

The average retail price for 30 acyclovir 400 mg tablets is $25.85. The average retail price for 30 valacyclovir 500 mg tablets is $124.46. Keep in mind that you may need to take acyclovir more frequently than valacyclovir, and your therapy may require more pills.

If your insurance does not cover your medication, you can use a prescription discount card to get the lowest prescription price at a pharmacy near you.

How Do Prescription Discount Cards Work?

Prescription discount cards allow you to compare prescription prices to obtain up to 80% or more off the average retail price of your medication. If your insurance does not pay for your medicine or the price is too high, you can use a prescription discount card instead of your insurance. Download the mobile app today to get the most from your free RX savings card.

Rosanna Sutherby is a freelance medical writer who has been a practicing pharmacist in her community for close to 20 years. She obtained her Doctor of Pharmacy from Nova Southeastern University in Ft. Lauderdale, FL. She utilizes her clinical training in the pharmacy, where she helps patients manage disease states such as asthma, diabetes, heart disease, hypertension, and many others. Dr. Sutherby reviews and recommends drug regimens based on patients’ concurrent conditions and potential drug interactions.

References:

https://www.wellrx.com/ACYCLOVIR/drug-information/

https://www.wellrx.com/VALACYCLOVIR/drug-information/

https://www.accessdata.fda.gov/drugsatfda_docs/label/2008/020487s014lbl.pdf

https://www.ncbi.nlm.nih.gov/books/NBK542180/

https://www.wellrx.com/health-conditions/about/health-condition/cold-sores/~default/

https://www.wellrx.com/health-conditions/about/health-condition/genital-herpes/~default/

https://www.wellrx.com/health-conditions/about/health-condition/shingles-and-postherpetic-neuralgia/~default/

https://www.pdr.net/drug-summary/Acyclovir-acyclovir-sodium-670

https://www.mayoclinic.org/drugs-supplements/acyclovir-oral-route-intravenous-route/description/drg-20068393

https://www.mayoclinic.org/drugs-supplements/valacyclovir-oral-route/description/drg-20066635

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5083079/