What is the treatment for Herpes Simplex Virus (HSV) infections?

Treatment of Herpes Simplex Virus (HSV) Infections

The first-line treatment for HSV infections consists of oral antiviral medications including acyclovir, valacyclovir, and famciclovir, with specific regimens tailored to whether it's a first clinical episode, recurrent episode, or suppressive therapy. 1

First Clinical Episode Treatment

• For first clinical episodes of genital herpes, recommended regimens include:

  • Acyclovir 400 mg orally three times daily for 7-10 days 2, 1
  • Acyclovir 200 mg orally five times daily for 7-10 days 2, 1
  • Famciclovir 250 mg orally three times daily for 7-10 days 2, 1
  • Valacyclovir 1 g orally twice daily for 7-10 days 2, 1

• Treatment may be extended if healing is incomplete after 10 days of therapy 2

• For severe disease requiring hospitalization (such as disseminated infection, pneumonitis, hepatitis, or CNS complications):

  • Acyclovir 5-10 mg/kg body weight IV every 8 hours until clinical resolution 2, 3
  • Patients may be switched to oral therapy after lesions begin to regress 2

Recurrent Episodes Treatment

• For recurrent episodes, shorter treatment courses are recommended:

  • Valacyclovir 500 mg orally twice daily for 5 days (preferred due to convenient dosing) 1, 4
  • Acyclovir 400 mg orally three times daily for 5 days 2, 4
  • Acyclovir 800 mg orally twice daily for 5 days 2, 4
  • Acyclovir 200 mg orally five times daily for 5 days 2, 4
  • Famciclovir 125 mg orally twice daily for 5 days 1, 4

• Treatment is most effective when started during the prodrome or within 1 day after onset of lesions 1, 4

• Delayed treatment beyond 72 hours significantly reduces effectiveness 4

Suppressive Therapy

• Daily suppressive therapy is recommended for patients with frequent recurrences (≥6 episodes per year) 1, 4:

  • Valacyclovir 1 g orally once daily or 500 mg orally once daily 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, 4

• After 1 year of continuous suppressive therapy, consider discontinuation to reassess the patient's rate of recurrent episodes 2, 4

Special Populations

HIV-Infected Patients

• HIV-infected patients may require higher doses and longer duration of therapy 5:

  • For suppressive therapy: Valacyclovir 500 mg twice daily 2, 5
  • Short-course therapy (1-3 days) should not be used in HIV-infected patients 2, 5
  • Daily suppressive therapy in HIV-infected persons also results in a decrease in HIV concentration in plasma and genital secretions 2

• For acyclovir-resistant HSV (suspected if lesions don't resolve within 7-10 days of treatment):

  • IV foscarnet is the treatment of choice 2, 5
  • Topical cidofovir may be an alternative for resistant cases 6

Pregnant Women

• Safety considerations are important for pregnant women 2
• Acyclovir has the most reported experience in pregnancy and appears to be safe 2

Important Clinical Considerations

• Topical acyclovir is substantially less effective than systemic therapy and is not recommended 2, 1, 4

• Systemic antiviral drugs partially control symptoms but do not eradicate latent virus or affect subsequent recurrences after discontinuation 2, 7

• For oral herpes (cold sores), similar antiviral medications are effective:

  • Oral valacyclovir, famciclovir, or acyclovir for 5-10 days 2, 8
  • Early application of 5% acyclovir cream may reduce lesion duration 8

• Counseling is an essential component of management 2:

  • Advise patients to abstain from sexual activity when lesions or prodromal symptoms are present 1
  • Encourage consistent condom use to reduce HSV-2 transmission 2, 5
  • Inform patients about the natural history of the disease, potential for recurrent episodes, and asymptomatic viral shedding 2

Treatment Failure Considerations

• If symptoms persist beyond expected healing time, consider:

  • Incorrect diagnosis 1
  • Poor medication adherence 1
  • Antiviral resistance (particularly in immunocompromised patients) 2, 6
  • Confirm resistance through viral culture and susceptibility testing 2, 5

• For immunocompromised patients with suspected acyclovir-resistant HSV, alternative treatments include:

  • IV foscarnet (40 mg/kg body weight IV every 8 hours) 2, 6
  • Topical cidofovir gel 1% applied once daily for 5 consecutive days 2, 6