Key takeaways:
Valtrex (valacyclovir) is an oral antiviral that treats herpes virus infections, such as cold sores and shingles. It’s generally safe to take Valtrex with most medications.
Combining Valtrex with certain antivirals, nonsteroidal anti-inflammatory drugs (NSAIDs), and medications that can be hard on your kidneys can raise the risk of side effects such as kidney damage.
It’s typically OK to take Valtrex with prednisone, topical herpes treatments, and over-the-counter pain relievers (other than NSAIDs). But it’s best to avoid alcohol while taking Valtrex for an active outbreak.
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Valtrex (valacyclovir) is an oral antiviral medication. It treats infections caused by herpes simplex and herpes zoster viruses, such as cold sores, genital herpes, and shingles. Some people take Valtrex as needed when an outbreak happens. Others take it on a regular basis to prevent outbreaks from happening.
Regardless of how often you take Valtrex, it’s helpful to know if it interacts with other medications. This can help you prevent any unwanted issues. Here, we’ll answer five common questions about Valtrex interactions to help you get the most from your medication.
1. Does Valtrex interact with other medications?
Valtrex doesn’t interact with many other medications. It’s generally well tolerated, and there aren’t any medications that you need to completely avoid while taking it.
That being said, there are some medications that can raise the risk of Valtrex side effects. This includes medications that are hard on your kidneys and some other antiviral medications. Here’s what you should know.
Medications that can be hard on your kidneys
Valtrex can cause kidney problems in rare cases. If you take it along with other medications that can be hard on your kidneys, the risk of kidney problems goes up. This includes medications such as:
Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil)
Diuretics (water pills), such as furosemide (Lasix)
Angiotensin-converting enzyme (ACE) inhibitors, such as lisinopril (Zestril)
Certain antibiotics, such as vancomycin and aminoglycosides
Zoledronic acid (Reclast, Zometa)
In some cases, you can still take Valtrex with these medications, especially if you only take Valtrex as needed. But you should only do so with your prescriber’s OK. They’ll likely keep a close eye on your kidney function to monitor for any issues caused by combining the medications.
Other antiviral medications
Taking Valtrex with other antiviral medications can raise your risk of side effects. These side effects can include nausea and stomach pain as well as kidney problems. Antivirals that carry this risk include:
Acyclovir
Famciclovir
Cidofovir
Ganciclovir (Zirgan, Cytovene)
Valganciclovir (Valcyte)
Tenofovir (Viread)
Zidovudine (Retrovir)
There are certain situations that may require you to take more than one antiviral medication at a time — for example, if you take antivirals for HIV and experience a herpes outbreak. Just be sure your prescriber is aware of what medications you’re taking, so they can watch for any issues.
You’ll likely only take one oral antiviral herpes medication at a time. Combining treatments doesn’t have any added benefit, but it can increase the risk of side effects.
2. Can you use topical herpes treatments while taking Valtrex?
Yes, it’s typically fine to use topical herpes creams or ointments while taking Valtrex. Topical products work locally to help manage symptoms. They don’t enter the bloodstream in large amounts, so they shouldn’t interfere with Valtrex or increase the risk of side effects.
Tips for taking Valtrex (valacyclovir): Experts cover how long Valtrex takes to work and tips for taking the medications.
Famvir (famciclovir) vs. Valtrex: Learn how these two cold sore treatments compare.
Valtrex side effects: Review possible Valtrex side effects and what to do if they occur.
Common topical treatments for herpes infections include:
Acyclovir (Zovirax) cream and ointment
Topical corticosteroids, such as hydrocortisone cream
Docosanol (Abreva)
Some topical treatments are sold over the counter (OTC), while others require a prescription. Your prescriber or pharmacist can help you find the right fit for your needs.
3. Can you take Valtrex with prednisone?
Yes, it’s fine to take Valtrex and prednisone (a corticosteroid) at the same time if your prescriber recommends it. Both medications can help relieve pain and resolve a herpes-related rash.
But both medications can also be hard on your stomach. So it’s a good idea to take them with food. And you may want to take Valtrex and prednisone at separate times of the day, if possible, to reduce the chance of nausea.
4. Can you drink alcohol while taking Valtrex?
There’s no direct interaction between Valtrex and alcohol. But alcohol can worsen some Valtrex side effects, such as:
Nausea
Dizziness
Headaches
Fatigue
Alcohol can also weaken your immune system, which can make it harder for your body to fight off a viral infection.
If you’re taking daily Valtrex to prevent a herpes outbreak, drinking a moderate amount of alcohol on occasion is likely fine. But it’s best to avoid alcohol if you’re dealing with an active herpes outbreak.
5. Can you take Valtrex with pain medications?
Whether it’s OK to combine Valtrex with a pain reliever depends on what type of pain medication it is. It’s best to get your prescriber’s OK before taking an NSAID, such as ibuprofen or naproxen (Aleve). As mentioned, NSAIDs can raise the risk of kidney problems if you take them with Valtrex.
But OTC pain relievers like acetaminophen (Tylenol) or a topical lidocaine cream are likely fine to combine with Valtrex.
The bottom line
Valtrex (valacyclovir) is an oral antiviral medication that treats and prevents infections caused by herpes viruses. It doesn’t interact with many medications. But taking Valtrex with certain antivirals or medications that can be hard on your kidneys can raise your risk of kidney damage and other side effects. You should also avoid alcohol while taking Valtrex for an active herpes outbreak.
It’s fine to combine Valtrex with topical herpes treatments and most over-the-counter pain medications. Just get your prescriber’s OK before taking it with nonsteroidal anti-inflammatory drugs (NSAIDs).
It’s also fine to take Valtrex with prednisone, although the combination can be hard on your stomach.
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References
Clinicalinfo.HIV.gov. (2025). Guidelines for the prevention and treatment of opportunistic infections in adults and adolescents with HIV: Herpes simplex virus. National Institutes of Health.
Clinicalinfo.HIV.gov. (2025). Guidelines for the prevention and treatment of opportunistic infections in children with and exposed to HIV: What's new in the guidelines. National Institutes of Health.
Redpharm Drug. (2023). Valacyclovir - valacyclovir tablet [package insert].
Valladales-Restrepo, L. F., et al. (2023). Pharmacological treatment of herpes zoster and factors associated with its recurrence. Antibiotics.
Yue, Z., et al. (2017). Association between concomitant use of acyclovir or valacyclovir with NSAIDs and an increased risk of acute kidney injury: Data mining of FDA adverse event reporting system. Biological and Pharmaceutical Bulletin.
