Description
Valacyclovir Tablets USP 500 mg is an antiviral medication used to treat infections caused by herpes viruses, including herpes zoster (shingles), genital herpes, and herpes labialis (cold sores). It is also used for the suppression of recurrent genital herpes and for prophylaxis of cytomegalovirus (CMV) infection following organ transplants. Valacyclovir is the L-valyl ester prodrug of acyclovir, which enhances oral bioavailability and is rapidly converted into acyclovir in the body.
Valacyclovir acts by inhibiting viral DNA replication, thereby limiting the spread and severity of the infection.
Mechanism of Action: Valacyclovir is converted to acyclovir by intestinal and hepatic enzymes after oral absorption. Acyclovir is then phosphorylated by viral thymidine kinase to its active triphosphate form, which inhibits viral DNA polymerase and incorporates into viral DNA, causing chain termination. This process limits viral replication and reduces the severity and duration of outbreaks.
Indications:
- Herpes zoster (shingles) in immunocompetent adults
- Initial and recurrent genital herpes in adults
- Suppression of genital herpes in patients with frequent recurrences
- Cold sores (herpes labialis)
- CMV prophylaxis in transplant patients (with higher doses)
