Valtrex, also known as valacyclovir, is a prescription medication used to treat viral infections caused by the herpes virus, including genital herpes, cold sores, and shingles. It belongs to a class of drugs called antivirals. Valtrex works by slowing the growth and spread of the herpes virus, helping to alleviate symptoms and reduce the duration of outbreaks. It is typically taken orally, with or without food, and the dosage may vary depending on the specific condition being treated. Valtrex is most effective when started at the first sign of an outbreak. It is important to follow the prescribed regimen, complete the full course of treatment, and consult with a healthcare professional for personalized guidance, potential side effects, and any concerns during treatment.

Valtrex
Valtrex
Valacyclovir (Valacyclovir Hydrochloride)
Select product strength & quantity:
Select product strength & quantity:

Prescription Required.

Product of Canada.

Shipped from Canada.

Prescription Required.Product of Canada.Shipped from Canada.

What is Valtrex?

Valtrex is a prescription medication used to treat a variety of viral conditions. In adults, it is indicated for:

Cold Sores: Valtrex can be used to treat cold sores, also known as herpes labialis. It is not known if Valtrex is effective after clinical cold sore symptoms (e.g., a vesicle, papule, or ulcer) have occurred.

Genital Herpes: Valtrex can be used after an initial episode of genital herpes within 72 hours of symptom onset. It can also be used for recurrent genital herpes episodes. Efficacy after 24 hours of symptom onset is not known. Additionally, Valtrex can be used as chronic suppressive therapy to prevent new episodes in both immunocompetent and HIV-1 infected patients. Valtrex can also reduce transmission of genital herpes and should be used in combination with safe sex practices.

Herpes Zoster: In immunocompetent adults, Valtrex can be used to treat herpes zoster (shingles) within 72 hours of rash onset.

Valtrex is also indicated in pediatric patients for:

Cold Sores: Valtrex can be used to treat cold sores in individuals 12 years of age or older. It is not known if Valtrex is effective after clinical cold sore symptoms (e.g., a vesicle, papule, or ulcer) have occurred.

Chickenpox: Immunocompetent pediatric patients aged two to 18 years of age can use Valtrex to treat chickenpox. Valtrex should be started within 24 hours after rash onset.

The safety and efficacy of Valtrex is not known in:

  • Individuals less than 12 years of age with cold sores
  • Individuals less than 2 years of age or greater than 18 years of age with chickenpox
  • Immunocompromised individuals for reasons other than genital herpes suppression in HIV-infected individuals that have a CD4+ cell count of greater than 100 cells/mm3
  • Individuals less than 18 years of age with genital herpes
  • Infants and neonates for herpes simplex virus (HSV) suppressive therapy
  • Individuals less than 18 years of age with herpes zoster

How does Valtrex work?

Valtrex is an antiviral medication that functions as a deoxynucleoside analogue DNA polymerase inhibitor. It works against the ?-herpes viruses.

Side Effects

Common side effects of Valtrex include:

  • Headache
  • Fatigue
  • Dizziness
  • Nausea
  • Vomiting
  • Stomach pain
  • Menstrual pain
  • Joint pain
  • Skin rash
  • Stuffy nose
  • Sore throat

Warnings & Precautions

Thrombotic Thrombocytopenic Purpura/Hemolytic Uremic Syndrome (TTP/HUS)

In clinical trials, individuals receiving Valtrex that had advanced HIV-1, allogenic bone marrow transplant, or renal transplant demonstrate TTP/HUS. Some cases resulted in death. Cases occurred at doses greater than 8 grams daily. Therefore, individuals should immediately discontinue Valtrex if experiencing symptoms of TTP/HUS.

Acute Renal Failure

There have been reports of acute renal failure in:

  • Individuals with underlying renal disease that take doses of Valtrex that are higher than what is recommended for their renal function. Patients with renal impairment should take lower doses of Valtrex.
  • Elderly individuals with or without decreased renal function. Elderly patients should use caution when using Valtrex. Additionally, if they have impaired renal function, the dose of Valtrex should be adjusted.
  • Individuals taking other nephrotoxic drugs. Patients should use caution when taking Valtrex concomitantly with other drugs that are nephrotoxic.
  • Individuals that are not sufficiently hydrated. In cases of dehydration, acyclovir has been reported to precipitate in the renal tubules. Therefore, patients should maintain adequate hydration while taking Valtrex.

If anuria or acute renal failure occurs, providers should consider hemodialysis until the patient’s renal function has recovered.

Effects on the Central Nervous System (CNS)

Patients with reduced renal function or with underlying renal disease taking higher than recommended Valtrex doses may experience CNS effects. For example, there have been reports of hallucinations, confusion, agitation, delirium, encephalopathy, or seizures in patients with underlying renal disease taking too high doses of Valtrex. Additionally, elderly individuals are at higher risk of developing CNS adverse effects. If a patient experiences CNS effects, Valtrex should be stopped.

Use in specific populations

Pregnancy

Data indicates that valacyclovir and its metabolite, acyclovir, do not cause birth defects. However, there is not enough data on its potential association with miscarriage or fetal or maternal outcomes. There are, however, risks associated with untreated herpes simplex virus during pregnancy, specifically to the fetus.

Lactation

There is no data on the presence of valacyclovir in human milk. Its metabolite acyclovir, however, is present in the milk after valacyclovir ingestion. There is no research indicating how acyclovir or valacyclovir may affect a breastfed infant or milk production. When prescribing Valtrex, providers should consider the mother’s need for Valtrex and the possible adverse effects associated with Valtrex and a breastfed infant.

Pediatrics

Valtrex can be used in children at least 12 years of age or older for the treatment of cold sores. This is based on data from two double-blind, placebo-controlled trials that evaluated Valtrex in adolescents with a history of cold sores. Valtrex can also be used to treat chickenpox in patients aged 2 to 19 years of age. This is based on a valacyclovir study and three supportive trials evaluating acyclovir in pediatrics.

The safety and efficacy of Valtrex is not known in:

  • Individuals less than 12 years of age with cold sores
  • Individuals less than two years of age or greater than 18 years of age with chickenpox
  • Individuals less than 18 years of age with genital herpes
  • Infants and neonates for herpes simplex virus (HSV) suppressive therapy
  • Individuals less than 18 years of age with herpes zoster

Geriatrics

In a study evaluating valacyclovir to treat herpes zoster, older participants experienced a longer duration of pain after healing than younger participants. Geriatric patients are more likely to have decreased renal function and need their valacyclovir dose reduced. Therefore, geriatric patients are at higher risk of having renal or CNS adverse events.

Renal Impairment

Individuals with renal impairment should take Valtrex at a lower dose than normal.

Frequently Asked Questions

Take Valtrex exactly as your doctor tells you to. Your dose will depend on what condition you are treating. If you are taking Valtrex for the purpose of cold sores, shingles, chickenpox, or genital herpes, take it as soon as you start having symptoms. Symptoms may include tingling, burning, itching, or appearance of a sore.

Make sure to stay well hydrated while taking Valtrex. Drink sufficient amounts of water throughout your course of therapy. If you are taking a Valtrex suspension, shake the bottle well prior to using.

Valtrex can be taken with or without regard to food.

If you overdose on Valtrex, contact your physician right away or immediately go to the closest emergency room.

If you miss a dose of Valtrex, take it once you remember. However, if it is close to the time when you would take your next dose, do not take the missed dose. Instead, take the next dose at your normal time. Never take more than one dose at a time or take it differently than prescribed by your doctor.

Always tell your doctor every medication you are taking, including prescription medicines, over-the-counter medicines, herbal supplements, and vitamins. Additionally, tell your doctor your entire medical history, including if you:

  • Have HIV-1 or acquired immune deficiency syndrome (AIDS)
  • Have problems with your kidneys, including if you get dialysis
  • Have had a kidney or bone marrow transplant
  • Are pregnant or plan to become pregnant. There is no data on how Valtrex will affect an unborn baby.
  • Are breastfeeding or plan to breastfeed. There is a chance that Valtrex passes into breastmilk. Discuss with your doctor the most appropriate way to feed your child while on Valtrex.

Common side effects of Valtrex include:

  • Headache
  • Fatigue
  • Dizziness
  • Nausea
  • Vomiting
  • Stomach pain
  • Menstrual pain
  • Joint pain
  • Skin rash
  • Stuffy nose
  • Sore throat

More serious side effects of Valtrex include:

  • Thrombotic Thrombocytopenic Purpura (TTP) and Hemolytic Uremic Syndrome (HUS): These conditions can lead to small blood clots and reduced blood flow. It can sometimes cause death. Both HUS and TTP have occurred in individuals taking Valtrex that have a weak immune system. If you experience TTP or HUS symptoms, your doctor will have you stop Valtrex treatment.
  • Kidney failure
  • Nervous system problems: Valtrex can sometimes cause problems with the nervous system. Elderly individuals are more likely to experience these effects. Alert your doctor immediately if you experience any of these signs or symptoms while taking Valtrex:
    • Unsteady movement
    • Speech issues
    • Hallucinations
    • Aggression
    • Shakiness
    • Seizures
    • Confusion
    • Coma

Keep Valtrex tablets at a temperature between 59° to 77°F (15° to 25°C). For a Valtrex suspension, keep it in the refrigerator between 36° to 46°F (2° to 8°C). Throw out any leftover Valtrex suspension after 28 days. Store Valtrex in a tightly closed container.