Treatment of Genital Herpes Simplex Virus (HSV) Infection
The recommended first-line treatment for genital herpes is oral antiviral therapy with valacyclovir, famciclovir, or acyclovir, with valacyclovir being the preferred option due to its convenient dosing schedule and excellent bioavailability. 1
Treatment Regimens Based on Clinical Scenario
Initial Episode
- Valacyclovir: 1 gram twice daily for 7-10 days
- Famciclovir: 250 mg three times daily for 7-10 days
- Acyclovir: 400 mg three times daily for 7-10 days 1
Recurrent Episodes
- Valacyclovir: 500 mg twice daily for 5-10 days
- Famciclovir: 125 mg twice daily for 5 days
- Acyclovir: 400 mg three times daily for 5-10 days 1
Clinical trials have demonstrated that valacyclovir is as effective as acyclovir for both episodic and suppressive treatment of genital herpes, with the advantage of less frequent dosing 2. For recurrent episodes, valacyclovir has been shown to reduce median time to lesion healing to 4 days compared to 6 days with placebo 3.
Suppressive Therapy
Suppressive therapy is indicated for patients with frequent recurrences (typically ≥6 episodes per year) or severe symptoms:
- Valacyclovir: 1 gram once daily (or 500 mg once daily for ≤9 recurrences per year)
- Acyclovir: 400 mg twice daily
- Famciclovir: 250 mg twice daily 1, 3
Clinical data shows that suppressive therapy with valacyclovir 1 gram once daily resulted in 34% of patients remaining recurrence-free at 12 months, compared to only 4% with placebo 3.
Special Populations
HIV-Infected Patients
- Require longer courses of therapy and closer monitoring
- For suppressive therapy: Valacyclovir 500 mg twice daily 1
- In HIV-infected adults, valacyclovir 500 mg twice daily resulted in 65% of patients remaining recurrence-free at 6 months compared to 26% with placebo 3
Pregnant Patients
- Acyclovir has an established safety profile and is preferred 1
- For women with known history of genital herpes, suppressive therapy starting at 36 weeks gestation is recommended to reduce the risk of recurrence at delivery 4
Immunocompromised Patients
- May require longer treatment duration and closer monitoring
- For severe manifestations: IV acyclovir 5-10 mg/kg every 8 hours for 5-7 days until clinical resolution 1
Acyclovir-Resistant HSV
In cases of suspected resistance (poor response to standard therapy after 5-7 days):
- Confirm HSV etiology and request susceptibility testing
- Consider foscarnet 40 mg/kg IV three times daily or 60 mg/kg twice daily for 10 days 5
- Alternative options include topical trifluridine or cidofovir (for accessible lesions) 5
Dose Adjustments for Renal Impairment
Acyclovir Dose Adjustments
| Creatinine Clearance (mL/min) | Dose Adjustment for 800 mg |
|---|---|
| >25 | 800 mg every 4 hours, 5 times a day |
| 10-25 | 800 mg every 8 hours |
| 0-10 | 800 mg every 12 hours |
Prevention of Transmission
- Avoid direct contact with active lesions
- Use latex condoms during sexual activity
- Consider daily suppressive antiviral therapy for those with frequent recurrences
- Valacyclovir is the only antiviral drug FDA-approved for reducing the risk of sexual transmission of HSV 1, 3, 2
Follow-up and Monitoring
- Re-examine patients 3-7 days after initiation of therapy to assess treatment response
- Advise patients to avoid sexual contact when visible lesions are present
- Counsel patients that while treatment can control symptoms and reduce transmission risk, it does not cure the infection 1
Common Pitfalls to Avoid
- Delayed treatment initiation: Antiviral therapy is most effective when started within 72 hours of symptom onset
- Inadequate treatment duration: Complete the full course even if symptoms improve
- Overlooking renal function: Dose adjustments are necessary for patients with impaired renal function
- Failing to address psychological impact: Genital herpes can cause significant psychological distress that may require additional support