Valaciclovir
Prescription status is set country by country — the label where you live is the one that applies.
Beta: the medication section is still being tested, and its data may contain errors. Do not rely on it for a decision about your own treatment.
Valaciclovir is a prodrug of aciclovir: the body converts it after absorption, so more of the active antiviral reaches the blood from each dose. The active form blocks the viral DNA polymerase of herpes viruses and stops them replicating. It is used for viral infections including cold sores, genital herpes and shingles.
A usual adult range, not a national label — the dose and the timing differ by country and by product.
Approved uses differ by country — some of these may be off-label or unapproved where you live.
It can be taken with or without food. Because it delivers a larger amount of aciclovir, keeping fluid intake up matters, since the drug is cleared by the kidneys and can crystallise there if a person is dehydrated. Reduced kidney function calls for caution and dose adjustment decided by a doctor, and creatinine and eGFR are the markers followed during longer or repeated courses. It is most effective when begun at the earliest symptoms.
A sharp fall in urine output, swelling, or new confusion, drowsiness or hallucinations are reasons to see a doctor promptly, especially where kidney function is already impaired. Unusual bruising, bleeding or widespread rash also needs medical review.
Reference information, not medical advice. Discuss any change with your doctor.