Valaciclovir

Valaciclovir, also spelled valacyclovir, is an antiviral medication used to treat outbreaks of herpes simplex or herpes zoster (shingles). It is also used to prevent cytomegalovirus following a kidney transplant in high risk cases. It is taken by mouth. Common side effects include headache and vomiting. Severe side effects may include kidney problems. Use in pregnancy appears to be safe. It is a prodrug, which works after being converted to aciclovir in a person's body. Valaciclovir was patented in 1987 and came into medical use in 1995. Valaciclovir is a therapeutic alternative on the World Health Organization's List of Essential Medicines. It is available as a generic medication. In 2023, it was the 98th most commonly prescribed medication in the United States, with more than 7 million prescriptions.