Recommended Antiviral Dosing for HSV1 Infections
The recommended daily antiviral dosing for HSV1 infections varies by clinical scenario, with acyclovir 400 mg orally twice daily being the standard suppressive therapy regimen for adults and adolescents with recurrent episodes. 1
Treatment Options by Clinical Scenario
Episodic Treatment for Recurrent HSV1 Infections
- Adults and adolescents: Acyclovir 400 mg orally three times daily for 5 days 1
- Children <45 kg: Acyclovir 20 mg/kg body weight (maximum 400 mg/dose) orally three times daily for 5-10 days 1
- Alternative regimens for adults:
Suppressive Therapy for Recurrent HSV1 Infections
- Standard regimen: Acyclovir 400 mg orally twice daily 1
- Alternative regimens:
Moderate to Severe Gingivostomatitis
- Initial therapy: Acyclovir 5-10 mg/kg body weight per dose IV three times daily 1
- Step-down therapy: Change to oral acyclovir after lesions begin to regress; continue until lesions completely heal 1
Mild Symptomatic Gingivostomatitis
- Acyclovir 20 mg/kg body weight (maximum 400 mg/dose) orally three times daily for 5-10 days 1
Special Populations
Immunocompromised Patients
- Recurrent orolabial or genital HSV in HIV-infected patients: Famciclovir 500 mg orally twice daily for 7 days 2
- Alternative regimen: Acyclovir 400 mg orally three to five times daily until clinical resolution 1
- For severe cases: Acyclovir 5 mg/kg IV every 8 hours until clinical resolution 1
Acyclovir-Resistant HSV Infection
- First-line therapy: Foscarnet 40 mg/kg body weight per dose IV three times daily or 60 mg/kg body weight per dose IV twice daily 1, 3
- Alternative therapy: Topical trifluridine or cidofovir 1% gel applied to lesions once daily for 5 consecutive days 1, 3
Important Considerations
- Valacyclovir and famciclovir have better bioavailability than acyclovir, allowing for less frequent dosing and potentially improved adherence 4
- Short-course therapy (1-3 days) should not be used in immunocompromised patients 1
- Dose adjustment is necessary for patients with renal impairment 5, 2
- For severe disease requiring hospitalization (disseminated infection, encephalitis, pneumonitis), intravenous acyclovir is indicated 1
- Long-term suppressive therapy is safe and effective for patients with frequent recurrences (≥6 episodes per year) 6
Treatment Duration
- Episodic therapy: 5-14 days depending on severity and immune status 1
- Suppressive therapy: Can be continued indefinitely, but reassessment after 12 months is recommended as recurrence frequency may decrease over time 1
- CNS or disseminated disease: 21 days of therapy 1
Remember that early initiation of therapy (within 24-48 hours of symptom onset) provides the greatest clinical benefit for episodic treatment of recurrences 7.