Duration of Suppressive Antiviral Therapy for Recurrent HSV Sores
Suppressive antiviral therapy for recurrent herpes simplex virus (HSV) sores can be safely continued for up to one year, after which therapy should be discontinued to reassess the patient's rate of recurrent episodes. 1
Recommended Suppressive Therapy Regimens
The CDC recommends the following first-line regimens for suppression of recurrent genital herpes:
- Valacyclovir 500 mg twice daily - First-line prophylactic regimen due to convenient dosing and established efficacy 1
- Acyclovir 400 mg twice daily - Alternative first-line option 1
Dosing Based on Recurrence Frequency
- For patients with <10 recurrences per year: Valacyclovir 500 mg once daily is effective 2
- For patients with ≥10 recurrences per year: Higher dosing is recommended 2:
- Valacyclovir 1 gram once daily
- Valacyclovir 250 mg twice daily
- Acyclovir 400 mg twice daily
Duration of Therapy
According to the FDA label for Valtrex (valacyclovir), "The efficacy and safety of valacyclovir for the suppression of genital herpes beyond 1 year in immunocompetent patients and beyond 6 months in HIV-1−infected patients have not been established." 3
Therefore:
- Immunocompetent patients: Up to 1 year of continuous therapy
- HIV-1 infected patients: Up to 6 months of continuous therapy
After completing the recommended duration:
- Discontinue therapy to reassess the patient's rate of recurrent episodes 1
- If frequent recurrences resume, suppressive therapy can be restarted
Efficacy of Suppressive Therapy
Suppressive antiviral therapy has been shown to:
- Reduce frequency of outbreaks by 70-80% 1
- Decrease severity and duration of breakthrough episodes 1
- Reduce asymptomatic viral shedding 4
- Valacyclovir 1g daily has demonstrated a 71% reduction in total HSV-2 shedding compared to placebo 4
Monitoring During Suppressive Therapy
- No laboratory monitoring is needed unless the patient has substantial renal impairment 1
- For patients with renal impairment, dosage adjustments are necessary based on creatinine clearance 1
- Monitor for treatment failure if lesions don't begin to resolve within 7-10 days 1
When to Consider Suppressive Therapy
Suppressive therapy is recommended for patients with:
- Frequent recurrences (≥6 episodes per year) 1
- Severe or prolonged episodes 1
- Significant psychological distress from recurrences 1
- Immunocompromised status with risk for severe disease 1
Management of Treatment Failure
If prophylaxis fails and frequent recurrences continue:
- Confirm adherence to medication regimen
- Consider increasing dose
- Consider switching to alternative antiviral agent
- Obtain viral culture and susceptibility testing if resistance is suspected 1
Safety Considerations
- Common adverse effects include nausea and headache
- Rare but serious effects include thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (with high-dose valacyclovir, 8 g/day) 1
- Safety profiles of all standard suppressive regimens are comparable 2
Remember that after discontinuing suppressive therapy, many patients will experience recurrences and may need to restart suppressive therapy based on the frequency and severity of recurrent episodes.