From the Guidelines
Valtrex (valacyclovir) is primarily used to treat herpes infections, including herpes simplex virus types 1 and 2, and is not exclusive to herpes simplex virus. Valtrex is an antiviral medication that works against several types of herpes viruses, including varicella-zoster virus and Epstein-Barr virus, by converting to acyclovir in the body, which then interferes with viral DNA replication, preventing the virus from multiplying 1. The medication is ineffective against other types of viruses like influenza, coronaviruses, or rhinoviruses. Some key points to consider when using Valtrex include:
- Typical dosages range from 500-1000 mg taken 1-3 times daily depending on the specific condition being treated, with treatment durations varying from 1-10 days for acute infections or continuous therapy for suppression of recurrent infections 1.
- Dosing strategies that are most feasible for patient adherence should be prioritized, as several dosing strategies of anti-herpesvirus medications have been studied and are FDA-approved for first clinical episode genital herpes, episodic therapy, and suppressive therapy 1.
- Always take Valtrex as prescribed by your healthcare provider, as dosing requirements differ based on the specific viral infection and your kidney function. It's also important to note that while episodic and suppressive therapy for genital HSV-1 infection have not been studied as comprehensively as for genital HSV-2, the same medication dosages and frequencies are recommended for genital HSV-1 infection 1.
From the FDA Drug Label
1 INDICATIONS AND USAGE
1.1 Adult Patients Cold Sores (Herpes Labialis) VALTREX is indicated for treatment of cold sores (herpes labialis). Genital Herpes Initial Episode: VALTREX is indicated for treatment of the initial episode of genital herpes in immunocompetent adults. Herpes Zoster VALTREX is indicated for the treatment of herpes zoster (shingles) in immunocompetent adults.
The Valtrex (Valacyclovir) drug label indicates that it is used to treat herpes simplex virus (HSV) infections, including:
- Cold sores (herpes labialis)
- Genital herpes It is also used to treat herpes zoster (shingles). Therefore, Valtrex (Valacyclovir) is specific to the herpes simplex virus and varicella-zoster virus, which causes herpes zoster (shingles) 2.
From the Research
Valtrex (Valacyclovir) Specificity to Herpes Simplex Virus
- Valtrex (Valacyclovir) is used to treat infections caused by herpes simplex virus (HSV) and varicella zoster virus, and for prophylaxis against cytomegalovirus (CMV) 3
- It is an effective drug for the suppression of recurrent episodes of genital herpes in immunocompetent and immunocompromised individuals 3, 4, 5, 6
- Valacyclovir has similar efficacy to acyclovir in the episodic and suppressive treatment of genital herpes 4, 5, 6
- It is also indicated in the reduction of the sexual transmission of herpes simplex virus infection and for the treatment of herpes labialis 4
- Valacyclovir is not exclusive to the treatment of herpes simplex virus, as it is also used to treat herpes zoster and varicella zoster virus infections 7, 5, 6
Mechanism of Action and Pharmacokinetics
- Valacyclovir is an oral prodrug that undergoes rapid and extensive first-pass metabolism to yield aciclovir and the essential amino acid L-valine 5
- The bioavailability of aciclovir from oral valaciclovir is considerably greater than that achieved after oral aciclovir administration 5
- Valacyclovir delivers therapeutic aciclovir concentrations when administered in a less frequent oral dosage regimen than is required for aciclovir 5
Clinical Efficacy and Tolerability
- Valacyclovir is as effective as aciclovir and famciclovir in the treatment of genital herpes and herpes zoster 4, 5, 6
- It is well tolerated, with a convenient dosing frequency for the treatment of genital herpes or herpes zoster 4, 5, 6
- Valacyclovir has an acceptable safety profile in patients with herpes simplex and herpes zoster 4, 6