What is the recommended treatment for Herpes Simplex Virus type 2 (HSV2)?

HSV-2 Treatment

Recommended First-Line Therapy

For first-episode genital HSV-2, treat with valacyclovir 1 g orally twice daily for 7-10 days, and for recurrent episodes, use valacyclovir 500 mg orally twice daily for 5 days. 1

Treatment by Clinical Scenario

First Clinical Episode

For patients presenting with their first episode of genital herpes, longer treatment courses are essential because initial infections tend to be more severe and prolonged:

• Valacyclovir 1 g orally twice daily for 7-10 days (preferred due to convenient dosing) 1
• Acyclovir 400 mg orally three times daily for 7-10 days 1
• Acyclovir 200 mg orally five times daily for 7-10 days 1
• Famciclovir 250 mg orally three times daily for 7-10 days 1

Extend treatment beyond 10 days if healing is incomplete. 1

Recurrent Episodes (Episodic Therapy)

For patients with infrequent recurrences who prefer treatment only during outbreaks:

• Valacyclovir 500 mg orally twice daily for 5 days (preferred first-line) 1
• Acyclovir 400 mg orally three times daily for 5 days 1
• Acyclovir 800 mg orally twice daily for 5 days 1
• Famciclovir 125 mg orally twice daily for 5 days 1

Critical timing consideration: Episodic therapy is most effective when started during the prodromal period or within 1 day after lesion onset. 1 Delayed treatment beyond 72 hours significantly reduces effectiveness. 1

Suppressive Therapy

For patients with frequent recurrences (≥6 episodes per year), daily suppressive therapy is highly effective:

• Valacyclovir 1 g orally once daily (or 500 mg once daily for those with ≤9 recurrences/year) 1
• Acyclovir 400 mg orally twice daily 1
• Famciclovir 250 mg orally twice daily 1

Suppressive therapy reduces recurrence frequency by ≥75% and reduces asymptomatic viral shedding. 1 After 1 year of continuous suppressive therapy, consider discontinuation to reassess recurrence frequency. 1

Special Populations

HIV-Infected Patients

HIV-infected patients require modified treatment approaches due to more severe disease and higher resistance rates:

For first episodes:

• Same regimens as immunocompetent patients but for 7-10 days minimum 2
• Extend treatment if healing is incomplete after 10 days 2
• For severe mucocutaneous lesions requiring hospitalization, use IV acyclovir until lesions regress, then transition to oral therapy 2

For recurrent episodes:

• Valacyclovir 500 mg orally twice daily for 5-10 days 2
• Acyclovir 400 mg orally three times daily for 5-10 days 2
• Do NOT use short-course therapy (1-3 days) in HIV-infected patients 2

For suppressive therapy in HIV patients:

• Valacyclovir 500 mg twice daily (note the twice-daily dosing, not once daily) 2
• Daily suppressive therapy decreases HIV concentration in plasma and genital secretions 2

Pregnant Women

Safety considerations are important during pregnancy, though specific HSV-2 treatment recommendations require careful consideration. 1

Treatment Failure and Resistance

Suspect acyclovir resistance if lesions do not begin to resolve within 7-10 days after initiating therapy. 3, 2

When resistance is suspected:

1. Obtain viral culture of the lesion 2
2. If virus is isolated, perform susceptibility testing to confirm drug resistance 2
3. For confirmed acyclovir-resistant HSV, use IV foscarnet 40 mg/kg every 8 hours as the treatment of choice 3, 2

Important context: Resistance rates in HIV-infected patients are nearly 10-fold higher than in immunocompetent individuals (6% vs 0.6%). 4

Critical Clinical Considerations

What NOT to Use

Topical acyclovir is substantially less effective than systemic therapy and is NOT recommended. 1, 5

Monitoring Requirements

• No laboratory monitoring needed for patients on episodic or suppressive therapy unless substantial renal impairment exists 3, 2
• For patients receiving high-dose IV acyclovir, monitor renal function at treatment initiation and once or twice weekly during treatment 3, 2
• Common side effects include nausea and headache 3, 2

Transmission Prevention Counseling

Suppressive therapy reduces transmission risk to sexual partners by approximately 50%. 1 Patients should:

• Abstain from sexual activity when lesions or prodromal symptoms are present 1
• Use condoms consistently during all sexual exposures 3, 1
• Understand that asymptomatic viral shedding can still occur and potentially transmit infection 1

Common Pitfalls to Avoid

1. Do not use short-course (1-3 day) regimens in HIV-infected patients - they require standard 5-10 day courses 2
2. Do not delay episodic treatment - effectiveness drops significantly if not started within 24 hours of lesion onset 1
3. Do not use valacyclovir 8 grams/day - associated with thrombotic thrombocytopenic purpura/hemolytic uremic syndrome in immunocompromised patients 5
4. Do not assume treatment failure is always resistance - consider incorrect diagnosis, co-infection with another STD, HIV infection, or poor medication adherence first 1