Recommended Regimens for HSV Prophylaxis
For suppression of recurrent genital herpes, valacyclovir 500 mg twice daily is the recommended first-line prophylactic regimen due to its convenient dosing and established efficacy. 1, 2
First-Line Prophylactic Options for Immunocompetent Patients
Genital HSV Prophylaxis:
- Valacyclovir options:
- 500 mg twice daily
- 1000 mg once daily
- Acyclovir options:
- 400 mg twice daily
- Famciclovir option:
- 250 mg twice daily
These suppressive regimens can reduce outbreak frequency by 70-80%, decrease severity and duration of breakthrough episodes, and reduce asymptomatic viral shedding 2.
Prophylaxis Duration and Monitoring
- Continue suppressive therapy for up to 12 months initially
- After 1 year of continuous therapy, consider discontinuing to reassess recurrence rate 3, 2
- No laboratory monitoring needed unless patient has substantial renal impairment 1
Special Populations
HIV-Infected Patients
- Valacyclovir: 500 mg twice daily
- Acyclovir: 400 mg twice daily 1
Note that daily anti-HSV suppressive therapy in HIV-infected persons results in decreased HIV concentration in plasma and genital secretions, though clinical benefit is uncertain 1.
Immunocompromised Patients (e.g., neutropenic)
- Valacyclovir: 500 mg twice daily
- Acyclovir: 400 mg three times daily 4
Renal Impairment
Dose adjustment required based on creatinine clearance:
Acyclovir dose adjustment: 3
| Creatinine Clearance (mL/min) | 400 mg Dose | 800 mg Dose |
|---|---|---|
| >25 | 400 mg q12h | 800 mg 5x daily |
| 10-25 | 400 mg q12h | 800 mg q8h |
| 0-10 | 200 mg q12h | 800 mg q12h |
Famciclovir dose adjustment: 5
| Creatinine Clearance (mL/min) | Adjustment for 250 mg q12h |
|---|---|
| ≥40 | 250 mg q12h |
| 20-39 | 125 mg q12h |
| <20 | 125 mg q24h |
| Hemodialysis | 125 mg following each dialysis |
Ocular HSV Prophylaxis
- Valacyclovir: 500 mg once daily
- Acyclovir: 400 mg twice daily 6
Both regimens show similar efficacy for preventing recurrent ocular HSV disease.
Important Clinical Considerations
When to Consider Prophylaxis
- Patients with frequent recurrences (≥6 episodes per year)
- Patients with severe or prolonged episodes
- Patients with significant psychological distress from recurrences
- Immunocompromised patients at risk for severe disease
Potential Side Effects
- Most common: nausea, headache
- Rare but serious: thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (with high-dose valacyclovir, 8 g/day) 1
Pregnancy Considerations
- Acyclovir is the preferred agent during pregnancy due to its established safety profile and most extensive clinical experience 1, 2
- Suppressive therapy is not routinely used during pregnancy but may be considered for women with frequent recurrences 1
Treatment Failure
If prophylaxis fails and frequent recurrences continue:
- Confirm adherence to medication regimen
- Consider increasing dose (e.g., valacyclovir 1000 mg daily)
- Consider switching to alternative antiviral agent
- For suspected resistance, obtain viral culture and susceptibility testing 1
Remember that immune reconstitution in HIV-infected patients receiving ART often improves the frequency and severity of clinical episodes, but does not reduce the frequency of genital HSV shedding 1.