Valacyclovir: Uses, Side Effects, Dosages, and Interactions

Share This Post

What is Valacyclovir? | Treatment Use | Treat Infections | How Long Does it take to Work? | Proper Dose | Side Effects | Drug Interactions

Many common medical conditions, including the childhood disease chickenpox, are caused by viruses.

Antiviral medication technology has improved dramatically over the past several decades, offering hope and relief from symptoms caused by illness from chickenpox to HIV. 

One popular antiviral medication, valacyclovir, can be used to treat a range of medical conditions caused by viruses, including conditions caused by the herpes simplex family of viruses. 

Commonly marketed under the brand name Valtrex, valacyclovir can help provide relief for patients experiencing symptoms from conditions like chickenpox, shingles, genital herpes, and oral herpes.

What Is Valacyclovir?

Valacyclovir is a generic prescription drug that is commonly sold under the brand name Valtrex.

Available in the form of an oral tablet only, valacyclovir belongs to a class of drugs called nucleoside analogs.

These medications work by mimicking one of the building blocks of DNA in order to stop the replication of viral DNA. Without the ability to replicate, the virus is unable to multiply and spread throughout the body.

Valacyclovir may be used on its own or in combination with other medications.

Although best known for its treatment of genital herpes under the brand name Valtrex, the medication also has a number of other uses and applications in the treatment of certain viruses.

Valacyclovir was first approved by the U.S.Food and Drug Administration (FDA) in 1995 under the brand name Valtrex.

Since the expiration of the original patent in 2009, the medication has been available for sale under its generic name, valacyclovir.

YouTube player

What Is Valacyclovir Used To Treat?

Valacyclovir is used to treat viral infections caused by herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2), as well as varicella-zoster virus (VZV).

The herpes simplex virus types are responsible for genital and oral herpes while the varicella-zoster virus is responsible for chickenpox and shingles.

Chickenpox

Chickenpox, the common childhood illness, occurs as a result of infection with the varicella zoster virus.

The condition causes small red bumps to spread across the body in an itchy rash. At first, the condition may look like insect bites or pimples.

Children with chickenpox are typically very itchy and may experience flu-like symptoms, including tiredness, fever, or body aches.

Valacyclovir can help to reduce the discomfort associated with chickenpox and may be prescribed to children between the ages of 2 and 18 who develop the condition and are not immunocompromised.

Shingles

Like chickenpox, shingles is caused by the varicella zoster virus.

However, it commonly affects adults.

This condition typically affects individuals who experienced chickenpox as children. Shingles is a serious illness that causes small, painful blisters to appear on the skin.

The blisters may occur throughout the body or just on a small part of the body, and the breakouts are sometimes attributed to stress.

Valacyclovir can be used to reduce discomfort caused by shingles.

Genital Herpes

Genital herpes is a sexually transmitted disease that causes small, painful blisters on or around the genital areas.

Spread through sexual contact, genital herpes is primarily caused by the herpes simplex virus type 2 and can be spread even when a person is not experiencing a flare up of the condition.

Valacyclovir can be used to reduce symptoms caused by a flare up of genital herpes and can also be used to prevent future flare ups in people who are not immunocompromised.

Oral Herpes

Oral herpes, sometimes referred to as cold sores, are small, painful blisters or sores that occur in or around the mouth, typically around the lips.

Oral herpes, also called herpes labialis, is usually caused by the herpes simplex virus type 1.

Oral herpes is spread by kissing or other skin to skin contact with an infected area; however, an individual does not need to be experiencing a flare up in order to spread the virus.

How Does Valacyclovir Treat Viral Infections?

Valacyclovir works in a variety of ways to treat viral infections caused by viruses in the herpes simplex family.

When ingested, the body converts valacyclovir into acyclovir. Once the medication is converted, it begins to inhibit viral DNA replication in two different ways. 

First, it works by inhibiting viral DNA polymerase and preventing the incorporation and termination of the growing viral DNA chain.

Second, it deactivates viral DNA polymerase. As a result, the viral infection is not able to spread, which helps to reduce symptoms and make the patient feel better more quickly. 

Valacyclovir works to suppress an active infection; it does not kill the virus as the virus can remain dormant in the body for years.

How Long Does It Take For Valacyclovir To Work?

The length of time it takes for patients to begin experiencing relief from symptoms depends on the reason why they are taking valacyclovir and the severity of the infection.

Patients experiencing an initial herpes outbreak or mild recurring symptoms will likely start to experience relief within two to three days. 

However, it may take longer to experience relief for severe outbreaks. Valacyclovir works best when it is taken quickly (within 48 hours) after symptoms emerge, so talk to your doctor about a prescription as soon as you notice symptoms.

How Do I Know What Dose of Valacyclovir To Take?

The dose of valacyclovir varies depending on the age of the patient and the reason for treatment. 

When taken for the treatment of chickenpox in children, valacyclovir is typically given as a dose of 20 milligrams (mg) per kilogram (kg) of body weight, and the dose is administered three times per day for five days.

Adults and children under the age of two should not be given valacyclovir for chickenpox unless determined necessary by a doctor.

For the treatment of shingles, adults typically take a dose of 1000 mg three times per day for a period of seven days. Valacyclovir is generally not prescribed to children for shingles, as it more commonly affects older adults, particularly those over the age of 55.

For the treatment of an initial outbreak of genital herpes, adults typically take 1000 mg of valacyclovir twice per day for a total of 10 days.

For the treatment of recurrent outbreaks, adults are typically prescribed a dose of 500 mg of valacyclovir taken twice per day for a total of three days.

For the prevention of genital herpes outbreaks, adults typically take 500 or 1000 mg of valacyclovir once per day.

Children needing to take valacyclovir for genital herpes must receive guidance from their doctor regarding the appropriate dosage and frequency for the medication.

For the treatment of oral herpes, adults typically take 2000 mg twice per day for one day, as do children ages 12 and older.

Children under the age of 12 must have their dose determined by a doctor.

Are There Any Side Effects of Valacyclovir?

Valacyclovir is known to cause some side effects with use.

Side effects associated with valacyclovir include common side effects, which usually do not require medical attention, and serious side effects, which require immediate medical attention. 

Common side effects associated with valacyclovir include:

  • Headache
  • Vomiting
  • Pain in the abdomen or stomach area
  • Nausea
  • Dizziness

Serious side effects of valacyclovir require immediate medical attention. These side effects include:

  • Kidney failure, as evidenced by:
    • Urinating less often than normal
    • Severe drowsiness
    • Swelling of the feet, ankles, or legs
  • Central nervous system effects, including:
    • Shaky or unsteady movements
    • Hallucinations
    • Aggressive behavior
    • Confusion
    • Seizures
    • Coma

What Drug Interactions Are Associated With Valacyclovir?

Some medications may interact with valacyclovir.

Certain medications may increase a patient’s risk of experiencing side effects, decrease the effectiveness of one or both medications, or affect the length of time that one or both medications work. 

Some medications that are known to interact with valacyclovir include:

  • Cimetidine
  • Clozapine
  • Varicella virus vaccination
  • Zoster virus vaccination
  • Antiviral medications
  • Tenofovir
  • Warfarin
  • Clopidogrel
  • Hepatitis B medications
  • Non-steroidal anti-inflammatory drugs (NSAIDs)
  • Probenecid
  • Theophylline
  • Zidovudine

Summary

Valacyclovir is an antiviral medication that is commonly used for the treatment of chickenpox, shingles, genital herpes, and oral herpes. 

The most common side effects of valacyclovir include headache, nausea, vomiting, abdominal pain, and dizziness.

Rarely, valacyclovir can cause kidney failure or central nervous system effects

The medication comes in the form of an oral tablet that is taken anywhere from one to three times per day. In addition to treating outbreaks of chickenpox, shingles, genital herpes, and oral herpes, valacyclovir can also be used to prevent outbreaks of genital herpes in patients who experience recurring outbreaks.

References, Studies and Sources:

Valacyclovir (Oral Route) Side Effects | Mayo Clinic 

Valacyclovir | U.S. National Library of Medicine 

Shingles – Symptoms and causes | Mayo Clinic 

Sesame Care

Find the best price for great doctors and specialists

  • Thousands of doctors and specialists
  • $13,000,000+ saved by patients
  • 95% patient satisfaction
  • 4.3 on TrustPilot
     

Popular Destinations

Recent Articles

Minoxidil

Minoxidil is a vasodilator that relaxes (widens) blood vessels and improves blood flow.

Minoxidil is used to treat severely high blood pressure (hypertension) that is causing symptoms or damaging your vital organs. Minoxidil is usually given together with two other medicines to help prevent serious side effects.

Minoxidil tablets should not be used to promote scalp hair growth. Only the topical form of minoxidil (Rogaine) is recommended for that use.

Read More »

Cialis

Cialis relaxes muscles of the blood vessels and increases blood flow to particular areas of the body.

Cialis is used to treat erectile dysfunction (impotence) and symptoms of benign prostatic hypertrophy (enlarged prostate).

Another brand of tadalafil is Adcirca, which is used to treat pulmonary arterial hypertension and improve exercise capacity in men and women. Do not take Cialis while also taking Adcirca, unless your doctor tells you to.

Read More »

Share On:

Subscribe To Our Newsletter

Get updates and learn from the best

More To Explore

How Much Does Cialis Cost?

In this article, we will explore the history and facts of Cialis and breakdown how much does Cialis cost. 

Nexplanon Implant: Is the Most Effective Birth Control on the Market Right for You?

Nexplanon is the newest form of long-acting reversible contraception (LARCs) that provides pregnancy prevention for up to three years. Nexplanon replaced the contraceptive implant

Hims ED Review: Does it Actually Work?

We’ve compiled a comprehensive Hims review that will tell you everything you need to know about the company, your treatment options, FAQs about Hims

Hims vs Roman: Complete Review

We’ve put together a complete review of Hims vs. Roman to help you choose the telehealth service that’s right for you. 

BlueChew vs Hims: Which ED Pill is Better?

Both BlueChew and Hims can help you save on your ED pills, but comparing the two, which is better? Consider this your Bluechew vs

The Best Hair Loss Treatment for Men: Comparison Guide

If you’re looking for the best hair loss treatment for men, look no further than this comparison guide.

Roman Review: Is This Erectile Dysfunction Treatment Legit?

Roman is a remote men’s health service that focuses on providing treatments and prescriptions for a multitude of men’s health problems, such as erectile

MobileHelp Review: Pros & Cons of This Medical Alert System

In a sea of options, MobileHelp is one medical alert system that stands out to us. It boasts thousands of strong customer reviews and

What is the Difference Between Alzheimer’s and Dementia?

There are many different types of dementia, the most common of which is Alzheimer's disease. Dementia is a general term used to describe a

What Happens When You Don’t Last? Premature Ejaculation Pills, Causes and Treatment

If you are suffering from premature ejaculation, you may be feeling that your sex life has been reduced to a frustrating experience. You might

BlueChew vs Roman: Which is Better?

BlueChew and Roman both men's health brands that offer erectile dysfunction treatments and ED pills. BlueChew products are typically less expensive, but fewer options

Is Alcohol Wreaking Havoc on Your Sexual Performance?

Drinking too much alcohol can wreak havoc on your sexual performance, while moderate alcohol consumption usually does not cause any issues. Excess alcohol consumption

Rex Md ED Review: What To Know Before You Sign Up

REX MD is a telehealth company that wants to reimagine the world of men’s healthcare. According to their site, they’re aiming to improve the

Hims Hair Loss Review: Is it Legit?

The Hims Total Hair Package contains clinically proven components that are effective at stopping hair loss and promoting hair growth, including saw palmetto thickening

Cialis vs Viagra: What’s the difference?

Cialis and Viagra can both be used to treat erectile dysfunction (ed) and benign prostatic hyperplasia (bph), but the medications are not interchangeable, and

How Much Sildenafil is Too Much? Maximum Dosage and Safety

If you’re considering treatment with sildenafil, you might be wondering how much sildenafil is too much and what the maximum dosage and safety concerns

Nutrafol Review: Are These Hair Supplements Effective?

Nutrafol is a telehealth company that offers a range of hair supplements for both men and women. Are these supplements effective, though?

How Does Viagra Work?

So, what is erectile dysfunction, how exactly does this wonder drug work to treat it, just like tadalafil, and how likely is it that

How Long Does it Take Viagra to Work?

If you’re wondering how long it takes for Viagra to work, we have everything you need to know about this popular little blue pill.

Prenatal Vitamins for Hair Growth: Do They Work?

Many women who aren’t expecting take prenatal vitamins for longer hair and stronger nails. This guide from Pharmacists.org explains if this strategy works.