Valacyclovir pills in Ro packages
Valacyclovir pills in Ro packages

Important Safety Information for Valacyclovir

What is the FDA-approved use of valacyclovir?

Valacyclovir is used to treat:

  • Cold sores: The efficacy of valacyclovir has not been established when treatment is started after the development of clinical signs of a cold sore (e.g., papule, vesicle, or ulcer).

  • Genital herpes

    • Initial episode: In patients with normal immune systems. The efficacy of treatment started more than 72 hours after the onset of signs and symptoms has not been established. 

    • Recurrent episode: In patients with normal immune systems. The efficacy of treatment started more than 24 hours after the onset of signs and symptoms has not been established. 

    • Chronic suppressive treatment: In patients with normal immune systems or in HIV-1–infected patients.The efficacy and safety of suppression of genital herpes beyond 1 year in patients with normal immune systems and beyond 6 months in HIV-1−infected patients have not been established. 

    • Reduce transmission: In patients with normal immune systems, used along with safer sex practices. Do not have sexual contact with your partner when you have any symptom or outbreak of genital herpes. Use a condom made of latex or polyurethane whenever you have sexual contact. 

Limitations of use:

  • The efficacy and safety of valacyclovir have not been established in immunocompromised patients other than for the suppression of genital herpes in HIV-1–infected patients. 

Who should not use valacyclovir?

Do not use valacyclovir if you have a known allergic reaction to valacyclovir.

How should I take valacyclovir?

You can take valacyclovir with or without food.

You should take valacyclovir exactly as prescribed. If your symptoms are not improving or you have any questions about changing or stopping medication, reach out to your Ro-affiliated provider for guidance.

What should I tell my Ro-affiliated provider before using valacyclovir?

  • Tell your Ro-affiliated provider all of the medications you are currently taking, including prescription, over-the-counter medications, vitamins, and herbal and dietary supplements. 

  • It’s important to share your entire medical history with your provider. In particular, tell your provider if you have or have a past history of:

    • Kidney problems

    • Bone marrow transplant or kidney transplant, or if you have advanced HIV-1 infection or acquired immune deficiency syndrome (AIDS). 

  • Tell your provider if you are pregnant, planning to become pregnant, or breastfeeding.

Withholding or providing inaccurate information about your health and medical history in order to obtain treatment may result in harm, including, in some cases, death.

What are the most serious side effects that I or a caregiver should monitor for when taking valacyclovir?

If you are experiencing a medical emergency, call 911 or seek immediate medical attention.

These serious side effects are rare, but can occur with valacyclovir. You or a caregiver should carefully monitor for these side effects, especially in the beginning of treatment and with dose changes.

  • Thrombotic Thrombocytopenic Purpura/Hemolytic Uremic Syndrome (TTP/HUS): TTP and HUS have happened in people with weakened immune systems taking valacyclovir and have led to death. TTP and HUS are disorders that can cause small blood clots to form throughout the body and decrease blood flow to body organs such as the brain, heart, and kidneys. Your provider will stop treatment if you have signs or symptoms of TTP and HUS. 

  • Acute Renal Failure: Cases of acute renal failure have been reported in elderly patients with or without reduced renal function; patients with underlying kidney disease who received higher than recommended doses of valacyclovir, patients who are taking other drugs that are damaging to the kidneys; and patients who are dehydrated.

  • Central Nervous System (CNS) Effects: CNS side effects, such as agitation, hallucinations, confusion, delirium, seizures, and encephalopathy, have been reported. Elderly patients are more likely to have these side effects.

What are the most common side effects of valacyclovir?

The most common adverse reactions reported in at least one indication by greater than 10% of adult subjects treated with valacyclovir and more commonly than in subjects treated with placebo are:

  • Headache

  • Nausea

  • Stomach pain

You are encouraged to report negative side effects of prescription products to the FDA. 

This information is not comprehensive. Please see the full Prescribing Information for complete safety information.