What is the recommended treatment for a patient with Herpes Simplex Virus type 1 (HSV1) infection?

Treatment of HSV-1 Infection

For HSV-1 infections, treatment depends on the clinical presentation: first episodes require 7-10 days of oral antivirals, recurrent episodes benefit from 5-day courses when started early, and patients with ≥6 recurrences per year should receive daily suppressive therapy. 1, 2

First Clinical Episode

Treat all first episodes with extended courses of oral antivirals for 7-10 days:

• Valacyclovir 1 g orally twice daily for 7-10 days is the preferred first-line regimen 1
• Alternative: Acyclovir 400 mg orally three times daily for 7-10 days 1
• Alternative: Acyclovir 200 mg orally five times daily for 7-10 days 3
• For severe disease requiring hospitalization (disseminated infection, encephalitis, pneumonitis, hepatitis): Acyclovir 5-10 mg/kg IV every 8 hours for 5-7 days or until clinical resolution 3, 1

Recurrent Episodes (Episodic Treatment)

Provide patients with a prescription to self-initiate at the first sign of prodrome or lesions:

• Valacyclovir 500 mg orally twice daily for 5 days is the preferred regimen for convenience and efficacy 1, 4
• Alternative: Acyclovir 400 mg orally three times daily for 5 days 1, 4
• Alternative: Acyclovir 800 mg orally twice daily for 5 days 1, 4
• Alternative: Famciclovir 125 mg orally twice daily for 5 days 1, 4

Critical timing considerations:

• Treatment must be started during prodrome or within 24 hours of lesion onset for maximum effectiveness 1, 2
• Delaying treatment beyond 72 hours significantly reduces effectiveness 1, 2
• Most immunocompetent patients with infrequent recurrences do not benefit from episodic treatment if started late 3, 2

Daily Suppressive Therapy

Initiate suppressive therapy for patients with ≥6 recurrences per year:

• Valacyclovir 500 mg orally once daily is preferred for once-daily convenience 2
• Alternative: Valacyclovir 1 g orally once daily 1, 2
• Alternative: Acyclovir 400 mg orally twice daily 3, 1, 2
• Alternative: Famciclovir 250 mg orally twice daily 2, 4

Benefits and duration:

• Reduces recurrence frequency by ≥75% 3, 2, 4
• Decreases asymptomatic viral shedding and transmission risk 2, 4
• Safety documented for up to 6 years with acyclovir and 1 year with valacyclovir 2, 4
• After 1 year of continuous therapy, discontinue to reassess recurrence frequency 3, 2, 4

Special Populations

Immunocompromised patients require more aggressive therapy:

• Acyclovir 400 mg orally three to five times daily until clinical resolution 1
• Famciclovir 500 mg twice daily has been effective in HIV-infected patients 1
• Higher doses or longer courses may be needed 1
• Suspect acyclovir resistance if lesions do not begin to resolve within 7-10 days 4, 5
• For proven or suspected resistance: Foscarnet 40 mg/kg IV every 8 hours 4, 5

Orolabial HSV-1 (cold sores):

• Acyclovir 5% cream applied topically at first sign of prodrome 6, 7
• Systemic therapy: Acyclovir 400 mg orally three times daily for 3-5 days 7
• Valacyclovir 500-1000 mg twice daily for 3-5 days 7
• Sunscreen (SPF ≥15) alone can prevent recurrences 7

Critical Pitfalls to Avoid

• Never use topical acyclovir alone for genital herpes—it is substantially less effective than oral therapy 3, 1, 2, 4
• Do not initiate suppressive therapy in patients with <6 recurrences per year—the benefit does not justify continuous medication 2, 4
• Do not withhold a prescription for episodic treatment even if the patient is not on suppressive therapy—early self-initiated treatment is crucial 2
• Avoid valacyclovir 8 g/day in immunocompromised patients due to risk of hemolytic uremic syndrome/thrombotic thrombocytopenic purpura 4

Essential Patient Counseling

All patients require comprehensive counseling regardless of treatment approach:

• HSV-1 is a chronic, incurable infection with potential for recurrence 2, 4
• Asymptomatic viral shedding can occur even without visible lesions 3, 2, 4
• Abstain from sexual activity when lesions or prodromal symptoms are present 3, 4
• Use condoms during all sexual exposures to reduce transmission risk 3, 2, 4
• Inform sex partners about having HSV infection 4
• Discuss risk of neonatal infection with all patients, including men 2, 4