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Care365 medication guide
Valacyclovir
Treats herpes infections; cold-sore, genital-herpes and shingles regimens differ.
Drug information
Uses, directions and safety information for Valacyclovir.
What it is used for
Treats herpes infections; cold-sore, genital-herpes and shingles regimens differ.
How to use it
For cold sores in eligible patients, the source lists 2 g twice in one day, approximately 12 hours apart. Kidney impairment requires adjustment.
Before use
Avoid acyclovir/valacyclovir allergy; maintain appropriate hydration and check renal function.
Possible side effects
Headache, nausea and diarrhoea.
When to get medical help
Confusion, seizures, reduced urination or severe rash need urgent assessment.
Medicines and interactions
Review other medicines affecting kidney function or antiviral clearance.
Pregnancy and breastfeeding
Discuss pregnancy and breastfeeding; cold-sore use is product-approved from age 12.
Missed doses, storage and accidental exposure
Follow your own product’s missed-dose instructions. If you are unsure, ask a pharmacist before taking an extra dose. Contraceptives, injections and modified-release medicines may need a specific plan.
Keep the original packaging and follow its storage, expiry and disposal instructions. Keep medicines away from children and pets. Ask about refrigeration, after-opening limits and safe sharps disposal when relevant.
For suspected overdose or accidental swallowing, contact poison control or urgent medical care promptly. Call emergency services for breathing difficulty, collapse or a seizure.
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How Care365 can help
Explore care for your symptoms and prepare for a conversation about treatment. Your healthcare professional will consider your history, current medicines and whether an assessment or referral is appropriate.
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Know what to prepare and what to discuss.
Share your history
Prepare your symptoms, allergies, medication list and treatment questions.
Discuss your options
A healthcare professional assesses which care or referral is appropriate.
Plan your follow-up
Follow the advice you receive about treatment, monitoring and next steps.
Related condition guides
Learn about concerns where this medication may be discussed. Treatment depends on your individual assessment.
Prescription renewal and medication review
For a review of Valacyclovir, have your current dose, reason for treatment, remaining supply, benefits, side effects and pharmacy details ready. Ask your pharmacist or prescriber whether a renewal assessment is available and appropriate. A prescription or renewal is not guaranteed.
Questions about Valacyclovir
What is Valacyclovir used for?
Treats herpes infections; cold-sore, genital-herpes and shingles regimens differ.
How should I use Valacyclovir?
For cold sores in eligible patients, the source lists 2 g twice in one day, approximately 12 hours apart. Kidney impairment requires adjustment.
What side effects can Valacyclovir cause?
Headache, nausea and diarrhoea.
When should I get medical help while using Valacyclovir?
Confusion, seizures, reduced urination or severe rash need urgent assessment.
Can Valacyclovir interact with other medicines?
Review other medicines affecting kidney function or antiviral clearance.
What should I know about Valacyclovir during pregnancy or breastfeeding?
Discuss pregnancy and breastfeeding; cold-sore use is product-approved from age 12.
Sources and product information
Sources checked 2026-09-08. Safety sections are highlights; consult the full product information for complete warnings and instructions.
Check the Canadian Drug Product Database by product name or DIN for current product information.
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