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As is the case with any other medication, there may be some instances where valacyclovir‘s use is not recommended or dosage will have to be adjusted in order to prevent or reduce the risk of adverse interactions occurring from other drugs, medical conditions, or even food and drink.

Drug Interactions

According to the Mayo Clinic, drugs that may interact with valacyclovir include the following.

  • Dichlorphenamide (Keveyis)
  • Foscarnet (Foscavir)
  • Leflunomide (Arava)
  • Teriflunomide (Aubagio)
  • Tolvaptan (Samsca)

Please note that this list may not be complete, and other interactions with drugs not listed here may occur.

Valacyclovir and Birth Control

Some antiviral medications can interfere with oral birth control pills, but these medications are primarily for HIV, not infections from a herpes virus. Valacyclovir is not on that list. There is therefore no indication that valacyclovir interacts with birth control pills. That said, you should tell your doctor that you take them anyway. 

Valacyclovir and Tylenol

There is no indication that valacyclovir interacts with Tylenol (acetaminophen). 

Valacyclovir and Ibuprofen

There is some indication that valacyclovir might interact with drugs that affect the kidneys, such as ibuprofen (Advil). Anyone taking ibuprofen should tell their doctor before using an antiviral medication like valacyclovir. 

Valacyclovir and Acyclovir

Valacyclovir (Valtrex) and acyclovir (Sitavig, Zovirax) are two extremely similar medications with the same mechanism of action. That means they should not be taken at the same time unless recommended by a physician. 

Valtrex and Benadryl

Although some medications do interact with Benadryl (diphenhydramine), there is no indication that Valtrex is one of them. 

Food Interactions

Sometimes the foods we eat and the beverages we drink can also interact with our medications. There are no food interactions noted for Valtrex, however. Please note that this list may not be complete, and there may be other foods and beverages that interact with this drug.

Valacyclovir and Alcohol

For more information, please visit our page on valacyclovir and alcohol interactions.

Valacyclovir and Caffeine

There is no specific indication that caffeine affects valacyclovir. Still, it is best to check with a medical professional to see if it might enhance specific side effects, such as headaches. 

Disease & Conditions Interactions

Sometimes certain medications can increase the risk of harmful side effects for patients with specific diseases or other medical conditions.

According to the FDA, diseases, and medical conditions that are known to interact with Valacyclovir negatively include:

  • Advanced human immunodeficiency virus infection (HIV)
  • Bone marrow transplantation
  • Kidney transplantation
  • Kidney disease (end-stage renal disease)

Please note that this list may not be complete, and there may be other diseases and medical conditions where patients should not take valacyclovir.

Valacyclovir and Pregnancy

For more information, please visit our page on valacyclovir and pregnancy risks.

Valacyclovir and Coronavirus (COVID-19)

There is some interest in the use of antivirals to fight coronavirus, and studies are ongoing. There is currently no indication that someone infected with COVID-19 should stop taking valacyclovir.(if they are using it for a different indication) Instead, they should be sure their treating physicians know they take this drug or have taken it in the past.  There is currently no indication to take valacyclovir for COVID-19.

Valacyclovir and Breastfeeding

Studies show that lactating parents may pass a small amount of valacyclovir to babies in breast milk. While there is no indication that it is harmful, more testing needs to be done. Parents taking valacyclovir while nursing should be watched closely by medical professionals. 

Other Interactions

Other potential interactions include the following.

Valtrex and Sun Exposure

Taking valacyclovir might make the skin more sensitive to sunlight. Those using this drug should therefore take precautions and try to stay out of the sun as much as possible; if going out, they should use sunblock. 

Disclaimer: this article does not constitute or replace medical advice. If you have an emergency or a serious medical question, please contact a medical professional or call 911 immediately. To see our full medical disclaimer, visit our Terms of Use page.


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