Valtrex (Valacyclovir)

Type

Product

Manufacturer

Country

Dosage

Qty-Price (USD)

Type:

Product: Valtrex

Manufacturer: GSK

Country: Canada

Dosage: 500 mg

Qty-Price (USD):

Type:

Product: Valtrex

Manufacturer: GSK

Country: Canada

Dosage: 1000 mg

Qty-Price (USD):

Generic Equivalent of Valtrex

Type

Product

Manufacturer

Country

Dosage

Qty-Price (USD)

Type:

Product: Valacyclovir

Manufacturer: Generic

Country: Canada

Dosage: 500 mg

Qty-Price (USD):

Type:

Product: Valacyclovir

Manufacturer: Generic

Country: India

Dosage: 500 mg

Qty-Price (USD):

Type:

Product: Valacyclovir

Manufacturer: Generic

Country: New Zealand

Dosage: 500 mg

Qty-Price (USD):

Type:

Product: Valacyclovir

Manufacturer: Generic

Country: Canada

Dosage: 1000 mg

Qty-Price (USD):

Type:

Product: Valacyclovir

Manufacturer: Generic

Country: India

Dosage: 1000 mg

Qty-Price (USD):

Type:

Product: Valacyclovir

Manufacturer: Generic

Country: New Zealand

Dosage: 1000 mg

Qty-Price (USD):

Valtrex Information

medically reviewed by Carol Hou (BSc. Pharm) on June 27, 2025.

A licensed pharmacist (Licensed Community Pharmacies Directory | College of Pharmacists of British Columbia) with over 20 years of experience in medication management, specifically medication safety, she has reviewed the information for accuracy and completeness.

Valtrex and Valacyclovir at CanadaPharmacyOnline.com

The brand name Valtrex (valacyclovir) is manufactured by GSK (GlaxoSmithKline) in Canada.

Generic valacyclovir is sourced from manufacturers that meet applicable regulatory standards. The specific manufacturer of your dispensed medication may vary.

Important Information about Generic Valacyclovir:

Generic valacyclovir contains the same active ingredient as brand-name and is required to meet the same safety, effectiveness, and quality standards. This means it is designed to work in the same way as Valtrex. Studies have shown that generic valacyclovir is bioequivalent to brand-name Valtrex, meaning they have similar absorption rates and reach similar concentrations in the bloodstream. However, individual responses to medication can vary due to factors such as metabolism, genetics, and other health conditions.

For more information about generic drug approval and bioequivalence, you can visit the FDA website: https://www.fda.gov/drugs/generic-drugs/generic-drug-facts

Dosage:

Brand Valtrex and generic valacyclovir are commonly available in 500 mg and 1000 mg oral tablets.

Your doctor will determine the appropriate dose based on your individual needs and medical conditions.

Usage:

Valtrex (valacyclovir) is an antiviral medication primarily prescribed for infections caused by herpes viruses, including genital herpes (treating outbreaks, suppressing recurrences, and reducing transmission risk), cold sores, shingles, and chickenpox. Valtrex (valacyclovir) is most effective when started immediately after the first prodromal signs or symptoms of a herpes infection (e.g., tingling, itching, pain), ideally before blisters develop. Early treatment can help prevent or minimize the outbreak's severity and duration. Valtrex does not cure herpes infections, but it helps to manage the symptoms, shorten the duration of outbreaks, and in some cases, reduce the frequency of outbreaks and the risk of transmission.

Mechanism of Action:
Valtrex (valacyclovir) is an orally administered prodrug rapidly converted to its active form, acyclovir, in the body. Acyclovir's mechanism of action involves selectively inhibiting the herpes virus DNA replication. It is preferentially phosphorylated to acyclovir monophosphate by viral thymidine kinase in HSV-infected cells. In VZV-infected cells, acyclovir is primarily phosphorylated to acyclovir monophosphate by viral thymidine kinase, though cellular kinases can also contribute to its phosphorylation. Subsequently, cellular enzymes further phosphorylate it to the active acyclovir triphosphate (ACV-TP). ACV-TP competitively inhibits viral DNA polymerase, causes DNA chain termination upon incorporation, and can irreversibly bind to the polymerase, thus halting viral DNA synthesis and controlling herpes virus infections such as HSV-1, HSV-2, and VZV.

Take Valtrex exactly as your doctor prescribes, following the instructions in the product monograph in Canada. Consult your doctor for personalized guidance and safe use. The information below summarizes some, but not all, potential side effects, risks, and interactions. Before taking Valtrex, it is essential to discuss all possible side effects, risks, and interactions with your doctor or pharmacist.

Side Effects:

The information below outlines potential side effects associated with Valtrex(valacyclovir). It is not an exhaustive list, and individual reactions can vary.

Common side effects - These are some common side effects of Valtrex, but others are possible. Contact your doctor promptly if any side effects are persistent, worsening, or concerning, or if you experience any other concerning symptoms.
• Abdominal pain
• Dizziness
• Headache
• Nausea

Less common side effects can include:
• Diarrhea
• Joint pain
• Runny nose
• Skin rash
• Sore throat
• Tiredness
• Vomiting

Serious Side Effects: These are rare but potentially severe side effects. Seek immediate medical attention or call emergency services if you experience any of the following:
• Allergic reactions: Hives, difficulty breathing, swelling of the face, lips, tongue, or throat.
• Blood disorders: Unusual bleeding or bruising, tiny red spots on the skin (unrelated to herpes or chickenpox), pale skin, weakness, fainting.
• Kidney problems: Changes in the amount of urine, swelling in the legs or ankles.
• Liver problems: Yellowing of the skin or eyes, abdominal pain, nausea, vomiting.
• Mood changes: Depression, sadness or emptiness, irritability, loss of interest or pleasure.
• Nervous system problems: Agitation, confusion, hallucinations (seeing or hearing things that are not real), seizures, speech problems, aggressive behavior, shakiness.
• Severe skin reactions: Blistering or peeling skin, rash covering a large area of the body, rash with fever.

Contraindications:

The following is not an exhaustive list of contraindications. Before starting Valtrex, it is crucial to discuss all your medical conditions, past and present, and all medications you are taking with your doctor or pharmacist.

Valtrex should not be used if you:
• Are allergic to valacyclovir, acyclovir, or any other ingredients in the formulation. This is a primary contraindication, which can lead to a serious allergic reaction.
• Have had a previous allergic reaction to acyclovir (Zovirax). Because valacyclovir is converted to acyclovir in the body, a prior allergy to acyclovir is a strong reason to avoid valacyclovir.

Tell your doctor about all of your medical conditions, past and present, before starting Valtrex. This is crucial because certain conditions can affect whether Valtrex is right for you. These conditions may include, but are not limited to:
• History of bone marrow or kidney transplant: Similar to those with weakened immune systems, transplant recipients may have a higher risk of TTP/HUS.
• HIV/AIDS or a weakened immune system: People with weakened immune systems, including those with advanced HIV or who have had organ transplants, may have an increased risk of severe blood disorders (TTP/HUS) with Valtrex.
• Kidney disease: Valtrex can affect kidney function, and those with pre-existing kidney problems may need a lower dose or should avoid it altogether.

Drug Interactions:

Before taking Valtrex, it is essential to discuss all potential risks and interactions with your doctor or pharmacist. For complete and up-to-date information, refer to the Valtrex prescribing information.

Provide your doctor with a complete list of all your medications, including prescriptions, over-the-counter (OTC) drugs, vitamins, and herbal supplements. It is also important to inform your doctor about any herbal teas, recreational drugs, or significant dietary changes you are making, as these could potentially interact with Valtrex. Valtrex may interact with other medicines, but is not limited to:
• Acetazolamide and Amiloride: These diuretics can inhibit renal tubular secretion, a primary route of elimination for acyclovir (the active metabolite of valacyclovir). Concurrent use may increase acyclovir plasma concentrations, potentially increasing the risk of side effects. Caution and monitoring may be warranted.
• Bacitracin: Caution should be exercised when valacyclovir is used concomitantly with bacitracin due to the potential for additive nephrotoxic effects. Both drugs can impact kidney function, so renal function monitoring may be advisable.
• Drugs affecting the kidneys: Valacyclovir is primarily eliminated by the kidneys. Therefore, other medications that can affect kidney function may interact with valacyclovir by altering its levels in the body or increasing the risk of kidney-related side effects. These include:
o Nonsteroidal anti-inflammatory drugs (NSAIDs): Such as ibuprofen and naproxen. Some NSAIDs can potentially affect kidney function, which could theoretically impact the elimination of acyclovir (the active metabolite of valacyclovir). However, clinically significant interactions are uncommon in individuals with normal kidney function at typical doses. It is still important to inform your doctor about all your medications.
o Certain antibiotics: Like amikacin, gentamicin, tobramycin, and vancomycin.
o Antifungal medications, Such as amphotericin B.
o Cancer medications, Such as cisplatin and methotrexate.
o Immunosuppressants: Such as cyclosporine and tacrolimus.
o Other antiviral medications: Such as acyclovir, cidofovir, and foscarnet. Concurrent use of valacyclovir and acyclovir is generally not recommended as valacyclovir is rapidly converted to acyclovir in the body, leading to excessive acyclovir exposure and an increased risk of acyclovir-related side effects, such as kidney problems and neurological effects. This combination should only be considered under a healthcare professional's strict guidance and close monitoring. • Elvitegravir/cobicistat/emtricitabine/tenofovir DF: Tenofovir DF can affect kidney function, and cobicistat can influence the levels of co-administered drugs. Concurrent use with valacyclovir may increase the risk of renal adverse events. Monitoring of renal function is recommended.
• Cimetidine: Cimetidine can inhibit renal tubular secretion of acyclovir. Concurrent administration with valacyclovir may increase acyclovir plasma concentrations, potentially increasing the risk of acyclovir-related side effects. Dosage adjustments of valacyclovir may be necessary.
• Imipenem/cilastatin and Imipenem/cilastatin/relebactam: Concurrent use may increase the risk of central nervous system side effects, including seizures, potentially due to additive effects on the CNS or altered renal clearance, especially in patients with pre-existing seizure disorders or renal impairment. Close monitoring for neurological adverse events is warranted.
• Mycophenolate: The concurrent use of valacyclovir and mycophenolate may increase plasma concentrations of either or both drugs or their active metabolites. Monitoring for increased side effects of both medications may be necessary.
• Probenecid: Probenecid significantly inhibits the renal tubular secretion of acyclovir. Concurrent administration with valacyclovir will likely result in markedly increased acyclovir plasma concentrations and a prolonged half-life, increasing the risk of acyclovir-related side effects. Dosage adjustments of valacyclovir may be necessary.
• Talimogene laherparepvec: Valacyclovir, being an antiviral medication active against herpes simplex virus, may interfere with the replication of talimogene laherparepvec, a live oncolytic herpes virus therapy, potentially reducing its effectiveness. Concurrent use should be avoided.
• Tenofovir: The kidneys eliminate valacyclovir (as acyclovir) and tenofovir. Concurrent use may lead to increased plasma concentrations of either or both drugs due to competition for renal excretion. Additionally, tenofovir can have nephrotoxic effects, potentially increasing the risk of kidney problems when used with valacyclovir. Monitoring of renal function is recommended.
• Zidovudine (AZT): Concurrent use of valacyclovir and zidovudine may increase plasma concentrations of both drugs. This could potentially increase the risk of hematologic adverse events (such as neutropenia and anemia) and other side effects associated with either medication. Careful monitoring of blood counts and other signs of toxicity is advised.

Use in Children

The safety and effectiveness of valacyclovir have been established for the treatment of cold sores (herpes labialis) in pediatric patients 12 years of age and older, and for chickenpox (varicella) in pediatric patients 2 to 17 years of age (inclusive of 2, exclusive of 18). Consult the product monograph or a healthcare professional for complete details on approved uses and dosages in children.

Use in Elderly Patients

Older adults are more likely to have age-related kidney disease, increasing their risk of kidney-related side effects and central nervous system effects. Dosage adjustments may be needed.

Pregnancy and Breastfeeding

Valtrex should only be used during pregnancy if the potential benefits outweigh the risks to the fetus. Acyclovir, the active metabolite of valacyclovir, is present in breast milk. Discuss breastfeeding with your doctor while taking Valtrex.

Frequently Asked Questions about Valtrex at Canada Pharmacy Online:

Why is Valtrex more affordable in Canada than in the United States?

Prescription drug prices, including Valtrex, are generally lower in Canada than in the US due to a combination of factors, primarily government price regulations, differing market dynamics, and other economic considerations. In Canada, provincial and federal governments negotiate drug prices with pharmaceutical companies, which often results in lower costs compared to the U.S., where market forces play a more significant role. For more information, see the FAQs on Prescription Drug Importation from the Kaiser Family Foundation (KFF): https://www.kff.org/health-costs/issue-brief/faqs-on-prescription-drug-importation/

What is the difference between Valtrex 500 mg and 1000 mg?

The difference in dosage represents the different amount of the same active ingredient (valacyclovir) present in each tablet.

How much is the shipping?

Our shipping fee is a flat rate of $10.00 per order. Our pharmacy focuses on offering you the lowest prices on high-quality products.

How do I order from your pharmacy?

Ordering from us is very simple. You can purchase online or call Customer Service at 1866.920.3784; for more information or to learn about the ordering process, visit our How to Order page.

Is there a limit on how many tablets I am allowed to order at one time?

CanadaPharmacyOnline.com can only dispense a maximum of a three-month supply of Valtrex at once, per your doctor's prescription.

Can I buy over the counter from you?

No, Valtrex requires a valid prescription from your doctor. We do not sell this product without a valid prescription.

Do you ship to the United States?

Yes, we do. It usually takes 7 to 18 business days to receive your order from our pharmacy.

Is there a generic for Valtrex?

Yes, there is a generic alternative for this product called valacyclovir.

Does Valtrex cure herpes?

No, Valtrex does not cure herpes infections. It helps to manage the symptoms, shorten the duration of outbreaks, and reduce the frequency of recurrent outbreaks. It can also reduce the risk of transmission of genital herpes to others.

Can I spread herpes to others while taking Valtrex?

Yes, herpes infections are contagious, and you can still spread the virus to other people even when you do not have visible symptoms (asymptomatic shedding). However, the risk of transmission is significantly higher during an active outbreak. Consistent use of barrier methods like condoms can help reduce the risk of transmission, even during asymptomatic shedding.

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The information on this page is sourced from independent third parties contracted by CanadaPharmacyOnline. While we cannot guarantee its medical accuracy, we strongly recommend consulting a healthcare professional for personalized advice regarding medications or medical conditions.

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