What is the recommended medication for an Herpes Simplex Virus (HSV) outbreak?

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Last updated: August 10, 2025View editorial policy

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Recommended Medications for HSV Outbreak

For an active HSV outbreak, the recommended first-line treatment is oral acyclovir 400 mg three times daily for 5 days, or oral acyclovir 200 mg five times daily for 5 days, or oral acyclovir 800 mg twice daily for 5 days. 1

First-Line Treatment Options for Active Outbreaks

Acyclovir Options

  • Oral acyclovir 400 mg three times daily for 5 days
  • Oral acyclovir 200 mg five times daily for 5 days
  • Oral acyclovir 800 mg twice daily for 5 days 1

Alternative Options

  • Valacyclovir 500 mg twice daily for 5 days (or 1 gram twice daily for 1 day)
  • Famciclovir 125 mg twice daily for 5 days 1

Treatment Selection Based on Clinical Scenario

For First Episode Genital Herpes

  • Use higher doses and longer duration (7-10 days) of the above medications
  • Consider IV acyclovir 5-10 mg/kg every 8 hours for severe cases 1

For Recurrent Episodes

  • Start treatment within the prodrome or within 2 days of lesion onset for maximum benefit
  • Oral acyclovir 800 mg twice daily for 5 days is recommended 1

Suppressive Therapy Options

For patients with frequent recurrences (≥6 per year), suppressive therapy should be considered:

  • Valacyclovir 500 mg orally once daily (first-line option)
  • Acyclovir 400 mg orally twice daily
  • Famciclovir 250 mg orally twice daily 1

Valacyclovir is the only antiviral approved for once-daily suppressive therapy, which may improve adherence 2. Daily valacyclovir reduces the risk of transmission to susceptible partners by 50-75% and reduces asymptomatic viral shedding and recurrence rates 1.

Special Considerations

Renal Impairment

Dose adjustments are required for patients with renal impairment:

Creatinine Clearance (mL/min) Valacyclovir Dosing
≥50 (normal) No adjustment needed
30-49 No adjustment needed
10-29 500 mg every 24 hours
<10 500 mg every 24 hours
[1,3]

HIV Co-infection

  • Consider higher dosing of valacyclovir (500 mg twice daily)
  • More frequent monitoring for breakthrough outbreaks 1

Acyclovir-Resistant HSV

In immunocompromised patients who develop resistance to acyclovir (and related drugs):

  • Foscarnet 40 mg/kg IV three times daily or 60 mg/kg twice daily for 10 days
  • Cidofovir may be considered if foscarnet fails 4

Patient Education

  • Advise abstinence during active outbreaks or prodromal symptoms
  • Educate about potential prodromal symptoms (tingling, burning, itching)
  • Inform about asymptomatic viral shedding and transmission risk
  • Encourage consistent condom use during all sexual encounters 1

Comparative Efficacy

Valacyclovir appears to be somewhat better than famciclovir for suppression of genital herpes and associated viral shedding 5. In one study, HSV was detected on 3.2% of days among famciclovir recipients compared to 1.3% of days among valacyclovir recipients 5.

Monitoring

  • Follow up within 3-6 months for patients on suppressive therapy
  • Reassess need for continued suppressive therapy annually
  • Monitor for complications such as secondary bacterial infection
  • Assess response to therapy within 72 hours 1

References

Guideline

Herpes Management

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Research

Valacyclovir for the treatment of genital herpes.

Expert review of anti-infective therapy, 2006

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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