Valacyclovir and Acyclovir are both antiviral medications, and they both treat HSV-1, HSV-2, and herpes zoster infections.
They are also both pretty similar in their effectiveness against these viruses, and you should expect similar results from the use of either one when taken as directed.
So, just how are these two medications different from one another? There are a few subtle and more noticeable differences between Valacyclovir and Acyclovir that may help guide your doctor and you to prefer one over the other.
Below, we outline 9 differences between Valacyclovir (brand name Valtrex) and Acyclovir (brand name Zovirax).
Both medications can be used to treat the shingles virus (herpes zoster), cold sores (HSV-1), as well as genital herpes (HSV-2). But, only acyclovir is also used to treat the Epstein-Barr virus (mononucleosis).
The potential side effects from these medications are mostly the same, but there may be slight differences between the two.
Common side effects of Acyclovir may include: Diarrhea, nausea, and vomiting.
Common side effects of Valacyclovir may include: Mood changes, trouble sleeping, headache, loss of appetite, nausea, stomach pain, and fatigue.
Valacyclovir and Acyclovir are actually quite similar. So much so that Valacyclovir is converted into Acyclovir in the body.
Valacyclovir is considered a “prodrug” because it is inactive until it becomes converted into its active form once in the body.
Acyclovir is the active form of Valacyclovir.
Valacyclovir has a longer duration of action in the body than Acyclovir. This allows for a patient to dose Valacyclovir less frequently while still achieving adequate antiviral levels in the body to treat various viral infections.
Depending on what is being treated, Acyclovir may be dosed at 200mg to 800mg taken 4-5 times a day.
With Valacyclovir, less frequent dosing is commonly utilized. Depending on the condition, Valacyclovir dosing may be 500mg to 2,000mg 2-3 times daily.
Always use the strengths and dosing schedule prescribed to you by your doctor.
The forms that these medications are available in are different.
Valacyclovir is currently only manufactured in oral tablet form.
Acyclovir is manufactured in oral tablets, oral capsules, oral suspensions, sublingual tablets, topical creams, topical ointments, and an injectable solution.
Depending on what is being treated, your doctor may choose to use Acyclovir due to it having an expanded range of dosage forms.
If you are paying out of pocket for these medications, you may discover that there is a steep pricing difference between the two.
For most pharmacies, you will find a much higher cost per tablet for Valacyclovir than for Acyclovir.
One of the major benefits of Valacyclovir vs Acyclovir is its increased oral bioavailability. Meaning, it can get into your system much more than Acyclovir when taken as an oral tablet.
When Valacyclovir is taken by mouth, it is rapidly converted into Acyclovir in the body, leading to a 3-5 fold increase in the amount of Acyclovir bioavailable in the body than if you had taken oral Acyclovir.
Because of Valacyclovir’s increased bioavailability and longer duration of action, it is able to be dosed less frequently.
Due to this ability of less frequent dosing, it is more likely that a patient will be adherent to a treatment and is generally the preferred choice of the prescribing physician.
Valacyclovir is prescribed much more frequently for the above indications than Acyclovir.
You can have a free online telemedicine visit with our U.S. licensed doctors today to see if Valacyclovir treatment is a good fit for you.
If you are a good candidate for treatment, your prescription can be shipped to your front door with our free and fast shipping.
If you have any questions during your treatment, our staff and doctors are available for free unlimited follow-ups.