Maintenance Therapy for HSV-2
For daily suppressive therapy of genital HSV-2, use valacyclovir 500 mg twice daily, acyclovir 400 mg twice daily, or famciclovir 250 mg twice daily, with valacyclovir offering superior convenience and potentially better viral suppression. 1
Recommended Daily Suppressive Regimens
The CDC guidelines provide multiple equivalent options for HSV-2 suppression 1:
- Valacyclovir 500 mg twice daily (preferred for convenience and efficacy)
- Acyclovir 400 mg twice daily
- Famciclovir 250 mg twice daily
Alternative valacyclovir dosing includes:
- Valacyclovir 250 mg twice daily
- Valacyclovir 500 mg once daily
- Valacyclovir 1,000 mg once daily
Important caveat: Valacyclovir 500 mg once daily is less effective in patients with very frequent recurrences (≥10 episodes per year) 1.
Evidence Supporting Suppressive Therapy
Daily suppressive therapy reduces genital herpes recurrences by ≥75% among patients with frequent recurrences (≥6 per year) 1. Safety and efficacy have been documented for acyclovir for up to 6 years, and for valacyclovir and famciclovir for at least 1 year 1.
Comparative data suggest valacyclovir may be somewhat superior to famciclovir. In head-to-head trials, HSV was detected on 1.3% of days with valacyclovir versus 3.2% of days with famciclovir (relative risk 2.33,95% CI 1.18-4.89) 2. Additionally, valacyclovir once daily significantly reduces transmission risk to uninfected partners—reducing symptomatic transmission by 75% (hazard ratio 0.25) and overall HSV-2 acquisition by 48% (hazard ratio 0.52) 3.
Special Populations
HIV-Infected Patients
Use valacyclovir 500 mg twice daily specifically 4. HIV-infected patients require twice-daily regimens with any of the three antivirals, not once-daily dosing. Suppressive therapy in HIV-infected persons also decreases HIV concentration in plasma and genital secretions 4.
Immunocompromised Patients (Non-HIV)
Higher doses may be beneficial: acyclovir 400 mg orally 3-5 times daily or famciclovir 500 mg twice daily 1. Monitor for acyclovir resistance if lesions persist beyond 7-10 days of therapy 4.
Pregnancy
Acyclovir is the first-choice antiviral in pregnancy due to the most extensive safety data 4. Suppressive therapy starting at 36 weeks gestation is recommended for women with recurrent genital herpes to reduce cesarean delivery rates 4, 5, 6.
Clinical Considerations
When to initiate: Suppressive therapy should be discussed with every HSV-2-infected patient 4. It is particularly recommended for those with frequent or severe recurrences 4. Early initiation after diagnosis is effective—71% of newly diagnosed patients remained recurrence-free at 24 weeks on valacyclovir 1 g once daily versus 43% on placebo 7.
Duration and reassessment: After 1 year of continuous suppressive therapy, discontinuation should be discussed to reassess the patient's recurrence rate, as frequency often decreases over time 1. The 1998 guidelines noted insufficient experience with famciclovir and valacyclovir beyond 1 year, though more recent evidence supports longer-term use 1.
Limitations: Suppressive therapy reduces but does not eliminate asymptomatic viral shedding 1. Patients should be counseled that transmission risk persists even on therapy, though it is significantly reduced 3.
Resistance: Suppressive therapy has not been associated with clinically significant acyclovir resistance in immunocompetent patients 1. If resistance is suspected (lesions not resolving within 7-10 days), viral culture with susceptibility testing should be obtained, and IV foscarnet is the treatment of choice 4.
Adverse effects: Acyclovir, valacyclovir, and famciclovir are occasionally associated with nausea or headache but are generally well-tolerated 4, 8, 9. No routine laboratory monitoring is needed unless substantial renal impairment exists 4.