Treatment of HSV-1 vs HSV-2 Infections
Both HSV-1 and HSV-2 infections are treated with the same antiviral medications, with no difference in medication selection based on viral type, though treatment duration may vary based on whether it's a first episode or recurrence. 1, 2
First Clinical Episode Treatment
For first clinical episodes of genital herpes (either HSV-1 or HSV-2), longer treatment courses are recommended 2:
- Valacyclovir 1 g orally twice daily for 7-10 days
- Acyclovir 400 mg orally three times daily for 7-10 days
- Acyclovir 200 mg orally five times daily for 7-10 days
- Famciclovir 250 mg orally three times daily for 7-10 days
Treatment may be extended if healing is incomplete after 10 days of therapy 2
Severe mucocutaneous HSV lesions respond best to initial treatment with IV acyclovir 1
Recurrent Episodes Treatment
For recurrent episodes (either HSV-1 or HSV-2), shorter courses are recommended 2, 3:
- Valacyclovir 500 mg orally twice daily for 5 days
- Acyclovir 400 mg orally three times daily for 5 days
- Acyclovir 800 mg orally twice daily for 5 days
- Acyclovir 200 mg orally five times daily for 5 days
- Famciclovir 125 mg orally twice daily for 5 days
Episodic therapy is most effective when started during the prodromal period or within 1 day after onset of lesions 2, 3
Short-course therapy (1-3 days) should not be used in patients with HIV infection 1
Suppressive Therapy
Daily suppressive therapy is recommended for patients with frequent recurrences (≥6 episodes per year) 1, 2:
- Valacyclovir 1 g orally once daily or 500 mg orally once daily
- Acyclovir 400 mg orally twice daily
- Famciclovir 250 mg orally twice daily
Suppressive therapy can reduce recurrence frequency by ≥75% and reduce asymptomatic viral shedding 2, 3
After 1 year of suppressive therapy, consider discontinuation to assess recurrence frequency 2
Clinical Differences Between HSV-1 and HSV-2
- While treatment medications are the same, there are important clinical differences 1, 4:
- HSV-1 genital infections are typically less severe clinically and less prone to recur than HSV-2 genital infections 4
- HSV-1 is becoming more common than HSV-2 as a cause of genital infections in young women 5
- HSV-1 typically causes orofacial infections, while HSV-2 more commonly causes genital lesions, though crossover occurs 4, 6
Special Populations
HIV-Infected Patients
- HIV-infected patients may require longer courses of therapy than those recommended for HIV-negative patients 2
- Famciclovir 500 mg twice daily has been effective in reducing recurrences and subclinical shedding in HIV-infected patients 2
Treatment Failure Considerations
- If lesions do not begin to resolve within 7-10 days after initiation of therapy, consider treatment failure related to resistance 1
- For acyclovir-resistant HSV, IV foscarnet is the treatment of choice 1, 2
Important Clinical Considerations
- Topical acyclovir is substantially less effective than systemic therapy and is not recommended 2, 3
- Systemic antiviral drugs partially control symptoms but do not eradicate latent virus or affect subsequent recurrences after discontinuation 2, 7
- Valacyclovir has demonstrated antiviral activity against both HSV-1 and HSV-2 in cell culture 8
- Famciclovir is a prodrug of penciclovir, which has demonstrated inhibitory activity against both HSV-1 and HSV-2 9
Transmission Prevention
- Suppressive therapy with valacyclovir 500 mg once daily can reduce HSV-2 transmission to susceptible heterosexual partners by 50% 1, 10
- Patients should be counseled to abstain from sexual activity when lesions or prodromal symptoms are present 2, 3
- Consistent condom use should be encouraged to reduce HSV transmission 2