Important Safety Information for Valacyclovir

Read the Patient Information that comes with Valacyclovir before you start using it and each time you get a refill. There may be new information. This information does not take the place of talking to your healthcare provider about your medical condition or treatment. Ask your healthcare provider or pharmacist if you have questions.

Valacyclovir is used in adults:

• To treat cold sores (also called fever blisters or herpes labialis)
• To treat shingles (also called herpes zoster)
• To treat or control genital herpes outbreaks in adults with normal immune systems
• To control genital herpes outbreaks in adults infected with the human immunodeficiency virus (HIV) with CD4+ cell count greater than 100 cells/mm3
• With safer sex practices to lower the chances of spreading genital herpes to others. Even with safer sex practices, it is still possible to spread genital herpes.

Valacyclovir used daily with the following safer sex practices can lower the chances of passing genital herpes to your partner.

• 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.

Valacyclovir is used in children:

• to treat cold sores (for children ≥12 years of age)
• to treat chickenpox (for children 2 to <18 years of age)

Valacyclovir does not cure herpes infections (cold sores, chickenpox, shingles, or genital herpes).

The efficacy of valacyclovir has not been studied in children who have not reached puberty.

What are cold sores, chickenpox, shingles, and genital herpes?

Cold sores are caused by a herpes virus that may be spread by kissing or other physical contact with the infected area of the skin. They are small, painful ulcers that you get in or around your mouth. It is not known if valacyclovir can stop the spread of cold sores to others.

Chickenpox is caused by a herpes virus. It causes an itchy rash of multiple small, red bumps that look like pimples or insect bites usually appearing first on the abdomen or back and face. It can spread to almost everywhere else on the body and may be accompanied by flu-like symptoms.

Shingles is caused by the same herpes virus that causes chickenpox. It causes small, painful blisters that happen on your skin. Shingles occurs in people who have already had chickenpox. Shingles can be spread to people who have not had chickenpox or the chickenpox vaccine by contact with the infected areas of the skin. It is not known if valacyclovir can stop the spread of shingles to others.

Genital herpes is a sexually transmitted disease. It causes small, painful blisters on your genital area. You can spread genital herpes to others, even when you have no symptoms. If you are sexually active, you can still pass herpes to your partner, even if you are taking valacyclovir.

Valacyclovir taken every day as prescribed and used with the following safer sex practices, can lower the chances of passing genital herpes to your partner.

• 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.

Ask your healthcare provider for more information about safer sex practices.

Contraindications and Warnings:

• Do not take Valacyclovir if you are allergic to any of its ingredients or to Acyclovir. The active ingredient is Valacyclovir. 

Before taking Valacyclovir tell your healthcare provider:

About all your medical conditions, including:

• If you have had a bone marrow transplant or kidney transplant, or if you have advanced HIV disease or "AIDS". Patients with these conditions may have a higher chance for getting a blood disorder called thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS). TTP/HUS can result in death.
• If you have kidney problems. Patients with kidney problems may have a higher chance for getting side effects or more kidney problems with valacyclovir. Your healthcare provider may give you a lower dose of valacyclovir.
• If you are 65 years of age or older. Elderly patients have a higher chance of certain side effects. Also, elderly patients are more likely to have kidney problems. Your healthcare provider may give you a lower dose of valacyclovir tablets, USP.
• If you are pregnant or planning to become pregnant. Talk with your healthcare provider about the risks and benefits of taking prescription drugs (including valacyclovir tablets, USP) during pregnancy.
• If you are breastfeeding. Valacyclovir tablets, USP may pass into your milk and it may harm your baby. Talk with your healthcare provider about the best way to feed your baby if you are taking valacyclovir tablets, USP.
• About all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Valacyclovir tablets, USP may affect other medicines, and other medicines may affect valacyclovir tablets, USP. It is a good idea to keep a complete list of all the medicines you take. Show this list to your healthcare provider and pharmacist any time you get a new medicine.

Drug interactions:

• Other drugs that may cause kidney problems: Including nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, naproxen
• Acyclovir: Valacyclovir is very similar to Acyclovir. Do not use medications containing Acyclovir while using Valacyclovir.

What are the possible side effects of Valacyclovir?

Kidney failure and nervous system problems are not common, but can be serious in some patients taking valacyclovir. 

Nervous system problems include aggressive behavior, unsteady movement, shaky movements, confusion, speech problems, hallucinations (seeing or hearing things that are really not there), seizures, and coma. 

Kidney failure and nervous system problems have happened in patients who already have kidney disease and in elderly patients whose kidneys do not work well due to age. 

Always tell your healthcare provider if you have kidney problems before taking valacyclovir. Call your doctor right away if you get a nervous system problem while you are taking valacyclovir.

Common side effects of Valacyclovir in adults:

• Headache
• Nausea
• Stomach pain
• Vomiting
• Dizziness

Side effects in HIV-infected adults include headache, tiredness, and rash. 

These side effects are usually mild and do not cause patients to stop taking valacyclovir.

Other less common side effects in adults include:

• Painful periods in women
• Joint pain
• Depression
• Low blood cell counts
• Changes in tests that measure how well the liver and kidneys work.

The most common side effect seen in children <18 years of age was headache.

Talk to your healthcare provider if you develop any side effects that concern you.

These are not all the side effects of valacyclovir. For more information ask your healthcare provider or pharmacist.

Additional Resources

The following links provide further information on the potential risks and benefits of this medication:

• Official Valacyclovir PDR
• FDA Valacyclovir Prescribing Information

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