What is the recommended treatment for a patient co-infected with Herpes Simplex Virus 1 (HSV 1) and Herpes Simplex Virus 2 (HSV 2)?

Treatment for HSV-1 and HSV-2 Co-infection

The recommended treatment for patients co-infected with HSV-1 and HSV-2 is oral valacyclovir, which has superior bioavailability compared to acyclovir and can be administered with less frequent dosing while providing effective suppression of both viral types. 1

First-line Treatment Options

Episodic Treatment

For management of acute outbreaks:

• Valacyclovir: 1 gram twice daily for 7-10 days (first episode) or 500 mg twice daily for 5-10 days (recurrent episodes) 2, 1
• Famciclovir: 250 mg three times daily for 7-10 days (first episode) or 125 mg twice daily for 5 days (recurrent episodes) 2
• Acyclovir: 400 mg three times daily for 7-10 days (first episode) or 400 mg three times daily for 5-10 days (recurrent episodes) 2, 3

Suppressive Therapy

For patients with frequent recurrences (≥6 per year):

• Valacyclovir: 1 gram once daily (preferred) 1
• Acyclovir: 400 mg twice daily 1
• Famciclovir: 250 mg twice daily 2

Treatment Selection Considerations

Valacyclovir is preferred over acyclovir for several reasons:

1. Higher bioavailability (improved absorption)
2. Less frequent dosing (better adherence)
3. Clinical trials show valacyclovir 1 gram once daily provides effective suppression with 55% of patients remaining recurrence-free at 6 months 1
4. Valacyclovir has been shown to reduce HSV-2 transmission to susceptible partners by 50% when used as suppressive therapy 1

Short-course therapy (1-3 days) should not be used in patients with HSV-1 and HSV-2 co-infection as it may be inadequate for controlling both viral types 2.

Special Populations

HIV Co-infected Patients

• HIV-infected patients may require longer courses of therapy and closer monitoring 2, 3
• For suppressive therapy in HIV-infected patients: valacyclovir 500 mg twice daily 2
• In a study of HIV-infected adults on stable antiretroviral therapy, 65% remained recurrence-free with valacyclovir 500 mg twice daily for 6 months 1

Pregnant Patients

• Acyclovir has an established safety profile in pregnancy 3
• Valacyclovir (which converts to acyclovir in the body) is generally considered safe, though the FDA has not formally approved it for use during pregnancy

Immunocompromised Patients

• May require higher doses and longer duration of therapy 3
• Consider IV acyclovir for severe manifestations 2

Management of Treatment Failure

If lesions do not begin to resolve within 7-10 days of starting therapy, consider:

1. Incorrect diagnosis
2. Co-infection with another STI
3. Poor medication adherence
4. Development of antiviral resistance 2, 4

For suspected acyclovir/valacyclovir-resistant HSV (more common in immunocompromised patients):

• Consider foscarnet 40 mg/kg IV every 8 hours until clinical resolution 3
• Resistance testing may be warranted in persistent cases 4

Monitoring and Follow-up

• Re-examine patients 3-7 days after initiation of therapy to assess treatment response 2, 3
• For suppressive therapy, periodic clinical evaluation (every 6-12 months) is recommended to assess for adverse effects and continued need for therapy
• Monitor renal function in patients receiving high-dose therapy or those with renal impairment 3, 1

Patient Education

• Counsel patients about the risk of transmission to sex partners, even during asymptomatic periods 1
• Recommend consistent use of latex condoms to reduce HSV-2 transmission 2, 3
• Advise patients to avoid sexual contact when they have visible lesions 2
• Inform patients that antiviral medications reduce but do not eliminate viral shedding and transmission risk 1, 5
• Explain that these medications control symptoms but do not cure the infection 1

By following this treatment approach, patients with HSV-1 and HSV-2 co-infection can experience significant reduction in outbreak frequency, severity, and duration, leading to improved quality of life and reduced transmission risk.