What is the recommended dose of Valtrex (valacyclovir) for genital herpes suppression?

Valacyclovir Dosing for Genital Herpes Suppression

For genital herpes suppression therapy, valacyclovir can be prescribed as 500 mg once daily or 1,000 mg once daily, with the higher dose recommended for patients experiencing 10 or more recurrences per year. 1

Dosing Algorithm for Suppressive Therapy

The appropriate valacyclovir dosage for suppressive therapy depends on the frequency of recurrences:

1. For patients with <10 recurrences per year:

   • Valacyclovir 500 mg once daily 1, 2

2. For patients with ≥10 recurrences per year:

   • Valacyclovir 1,000 mg once daily 1, 2
   • Alternative: Valacyclovir 250 mg twice daily 1

Efficacy and Evidence

Suppressive therapy with valacyclovir has been shown to reduce the frequency of genital herpes recurrences by ≥75% among patients with frequent recurrences 1. Clinical trials have demonstrated that once-daily valacyclovir regimens are highly effective for suppression of recurrent genital herpes 2, 3.

A large-scale dose-finding study involving 1,479 immunocompetent patients showed a dose-response relationship across once-daily valacyclovir regimens, with higher doses providing better suppression 2. After 16 weeks of treatment with valacyclovir 500 mg once daily, 69% of patients remained recurrence-free compared to only 9.5% of patients on placebo 3.

Special Considerations

Duration of Therapy

• Safety and efficacy have been documented for valacyclovir for up to 1 year of continuous suppressive therapy 1
• After 1 year, consider discussing discontinuation to assess recurrence frequency, as recurrences may decrease over time 1

HIV Co-infection

For HIV-infected patients with a CD4+ cell count ≥100 cells/mm³:

• Recommended dosage: 500 mg twice daily 1, 4
• Higher doses may be needed as immunocompromised patients often benefit from increased antiviral dosing 1

Important Caveats

1. Asymptomatic Viral Shedding: Suppressive treatment reduces but does not eliminate asymptomatic viral shedding. Patients should be counseled that transmission can still occur during suppressive therapy 1.

2. Patient Counseling: Advise patients to:

   • Inform sexual partners about their infection
   • Use condoms during sexual activity
   • Abstain from sexual activity during outbreaks
   • Understand that transmission can occur during asymptomatic periods 1

3. Medication Adherence: The effectiveness of suppressive therapy depends on consistent daily medication use.

4. Safety Profile: Valacyclovir is generally well-tolerated with headache being the most commonly reported side effect 5. Allergic reactions are infrequent 1.

Valacyclovir offers the advantage of once-daily dosing compared to acyclovir's twice-daily regimen, potentially improving medication adherence for long-term suppressive therapy 6.