About valciclovir hcl
Antiviral; herpesvirus DNA polymerase inhibitor
Used for
- Treats cold sores, genital herpes, and shingles
- Suppresses recurrent genital herpes
- Helps prevent cytomegalovirus after organ transplantation
Usual adult dose
Common regimens: cold sores 2 g twice, 12 hours apart; genital herpes 500 mg twice daily for 3–10 days; shingles 1 g three times daily for 7 days.
Usual dose in children
For cold sores in children aged 12 years and older: 2 g twice, 12 hours apart. Other pediatric uses require specialist dosing.
Common side effects
- Headache
- Nausea
- Abdominal discomfort
- Dizziness
Important warnings
- Kidney problems may require dose reduction; maintain adequate hydration.
- Rare confusion, agitation, or seizures, especially with kidney impairment or older age.
- Seek urgent care for severe rash, unusual bruising, or reduced urination.
- Does not cure herpes or reliably prevent transmission.
Pregnancy
Use when clinically needed; available evidence has not shown an increased risk of major birth defects.
Breastfeeding
Valacyclovir passes into breast milk as acyclovir; exposure is generally low, but discuss risks with a clinician.
Interactions
- Probenecid may increase acyclovir levels.
- Cimetidine may increase acyclovir levels.
- Other 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 It may be incomplete or out of date.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.