About valacyclovir
Antiviral nucleoside analogue
Used for
- Cold sores and genital herpes
- Shingles
- Chickenpox in children
Usual adult dose
Herpes: 500 mg twice daily for 3–10 days; shingles: 1 g three times daily for 7 days.
Usual dose in children
Chickenpox: 20 mg/kg three times daily for 5 days, maximum 1 g per dose; for children aged 2–18 years.
Common side effects
- Headache
- Nausea
- Abdominal discomfort
- Dizziness
Important warnings
- Dose adjustment may be needed with kidney impairment.
- Rarely, confusion or other nervous-system effects occur, especially in older adults or kidney impairment.
- Treatment works best when started promptly.
- It does not cure herpes or prevent all transmission.
Pregnancy
Use when clinically needed; available evidence has not shown an increased risk of birth defects.
Breastfeeding
Small amounts enter breast milk; use is generally considered compatible with breastfeeding.
Interactions
- Probenecid may increase valaciclovir levels.
- Cimetidine may increase valaciclovir levels.
- Medicines affecting kidney function may increase kidney-related risks.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.