What is Valacyclovir?
Valacyclovir is a prescription medication that comes in the form of a tablet you take by mouth. It is available under the brand-name Valtrex but is also available as a generic drug. In some cases generic drugs cost much less than the brand-name version. In this article we discuss the uses, dosage and side effects of valacyclovir.
What is Valacyclovir Used For?
Valacyclovir is a prescription drug used to treat herpes simplex virus infections. This includes oral and genital herpes, shingles, and chickenpox.
- Oral herpes causes cold sores. Cold sores are small, sometimes painful sores that you can get in or around your mouth. They can be spread by kissing or other physical contact with the skin-infected area.
- Genital herpes is a sexually transmitted disease. Symptoms may include small, painful blisters at/or around the genital area. Even if you don’t have any noticeable symptoms you can still spread genital herpes to your sexual partner.
- Shingles is caused by the same virus that causes chickenpox (varicella zoster). Symptoms of shingles include painful blisters that appear on the skin. Shingles can occur in individuals who have already had chicken pox but it can also spread to people who have not had the virus before.
- Chickenpox causes an itchy rash of small, red-like bumps that can often be mistaken for pimples or insect bites. Chickenpox can also cause flu-like symptoms and the rash can spread to almost anywhere on the body.
How Does Valacyclovir Work?
Valacyclovir is a member of a class of drugs called “antivirals.” A class of drugs is a group of medications that work in similar way and are often used to treat similar conditions.
The herpes virus spreads throughout your body by replicating and creating more of its own cells. Valacyclovir doesn’t eliminate herpes from your body, but does make it harder for the herpes virus to multiply.
It is important to note that valacyclovir does not cure herpes. The herpes virus can still live in your body after treatment. This drug does, however, help prevent flare ups and re-infection at a later date.
Side Effects of Valacyclovir
Valacyclovir does have potential side effects—some more common and serious than others.
Common Side Effects
The most commonly reported side effects of valacyclovir include:
- Headache
- Nausea
- Dizziness
- Vomiting
- Abdominal pain
If these effects are mild, they may go away within a couples of days or a few weeks. If they’re more severe and don’t go away, talk to your doctor or pharmacist.
Serious Side Effects
Contact your doctor right away if you are experiencing any serious side effects. Call 911 immediately if you think any of your symptoms are life-threatening.
Kidney failure symptoms:
- Severe drowsiness
- Urinating less frequently than usual
- Swelling in your legs, ankles or feet
Abnormal mood or behavior:
- Aggressive behavior
- Confusion
- Seizures
- Coma
Disclaimer: Our goal at ManifestRX and Manifest Pharmacy is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects.
Valacyclovir Warnings
This medication comes with several warnings.
Allergy Warning
Valacyclovir may cause severe allergic reactions. This can include:
- Difficulty breathing
- Swelling of your tongue or throat
If you experience any of these symptoms go to the nearest emergency room or contact 911 right away. If you have an allergic reaction while using valacyclovir do not take it again.
Warnings For Certain Health Conditions
Kidney problems: Your kidneys excrete this drug from your body. If you have a history of kidney problems you may not be able to clear it from your body. Consequently, this can lead to a build up of this drug which can cause more side effects.
Advanced HIV or a history of transplant: Individuals with advanced HIV or a history of bone marrow or kidney transplant may be at a higher risk of developing certain blood disorders. If you have advanced HIV or a history of transplants speak with your doctor before beginning this medication.
Warnings For Other Groups
Pregnant women: Valacyclovir is a category B pregnancy drug. This means two things:
- Research in animals has not shown a risk to the fetus while the mother takes the drug
- There are little-to-no studies in humans to determine safety and risk to the fetus.
For women who are breastfeeding: This medication can pass into breast milk and may cause side effects in a child who is breastfed.
For seniors: The kidneys of older adults may not work as well as younger adults kidneys do. This can cause your body to process drugs more slowly. As a result, a higher amount of a drug stays in your body for a longer time which raises your risk of experiencing side effects.
How To Take Valacyclovir
Your dosage of valacyclovir can depend on a few different things:
- Your age
- How healthy you are
- The condition being treated
- How you respond to the first dose
Forms and Strengths
Generic: Valacyclovir
- Form: Tablet
- Strength: 500 mg or 1 g
Brand-name: Valtrex
- Form: Tablet
- Strength: 500 mg or 1 g
Oral Herpes Dosage
Ages 18-64 (Adult Dosage)
- Typical dosage: 2 g, twice daily for 1 day, taken 12 hours apart.
- It is best to begin treatment at the first sign of cold sore symptoms
Ages 12-17 (Child Dosage)
- Typical dosage: 2 g, twice daily for 1 day, taken 12 hours apart.
- It is best to begin treatment at the first sign of cold sore symptoms
Ages 0-11 (Child Dosage)
Valacyclovir has not been approved for use in children under 12 years of age.
Senior Dosage (Ages 65 Years and Older)
Your doctor may start you on a lower dose of valacyclovir. This is because the kidneys of older adults may not work as well as they used to which can cause your body to process drugs more slowly.
Genital Herpes Dosage
Ages 18-64 (Adult Dosage)
- First flareup: 1 g, taken twice daily for the first 10 days. For best results, begin valacyclovir within the first 48 hours of symptoms appearing.
- For prevention: 500 mg to 1 g once daily
- For preventing flare-ups in people with HIV: 500 mg, taken twice daily.
- To reduce the risk of transmission with a sexual partner: 500 mg taken once daily
Ages 0-17 (Child Dosage)
Valacyclovir has not been studied or approved for treatment of genital herpes in individuals younger than 18 years of age.
Ages 65 and Older (Senior Dosage)
Your doctor may start you on a lower dose of valacyclovir. This is because the kidneys of older adults may not work as well as they used to which can cause your body to process drugs more slowly.
Dosage For Shingles
Ages 18-64 (Adult Dosage)
- Typical dosage: 1 g, taken three times daily for 7 straight days
- It is best to begin treatment with valacyclovir within the first 48 hours of symptoms appearing
Ages 0-17 (Children Dosage)
Valacyclovir has not been approved for use in children under 18 years of age.
Ages 65 and Older (Senior Dosage)
Your doctor may start you on a lower dose of valacyclovir. This is because the kidneys of older adults may not work as well as they used to which can cause your body to process drugs more slowly.
Dosage For Chickenpox
Ages 18-64 (Adult Dosage)
- Typical dosage: 1 g, taken 3 times daily for 7 straight days.
- It is best to begin treatment with valacyclovir within the first 48 hours of symptoms appearing
Ages 2-18 (Child Dosage)
- Typical dosage: 20 mg per kilogram of body weight, taken 3 times daily for 5 straight days.
- Maximum dosage: 1 g, taken 3 times daily
- It is best to begin treatment with valacyclovir within the first 48 hours of symptoms appearing
Ages 0-1 (Child Dosage)
This drug has not been studied or approved for treatment of chickenpox in children younger than two years of age.
Senior dosage (ages 65 years and older)
Your doctor may start you on a lower dose of valacyclovir. This is because the kidneys of older adults may not work as well as they used to which can cause your body to process drugs more slowly.
Disclaimer: Our goal at ManifestRX and Manifest Pharmacy is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects.
Take As Directed
Valacyclovir is used for short-term treatment of oral herpes, genital herpes, shingles, or chickenpox. It’s used for long-term treatment to prevent genital herpes, and to treat genital herpes that recurs (comes back).
Take valacyclovir as prescribed. If you don’t, this drug can come with serious side effects.
Valacyclovir Side Effects, Uses & Dosage Summary
Valacyclovir is a prescription medication that comes in the form of a tablet you take by mouth. It is available under the brand-name Valtrex but is also available as a generic drug.
Valacyclovir is used to treat herpes simplex virus infections.
