Management of Oral HSV‑1 Infection in Adults

First‑Episode (Primary) Oral HSV‑1 Infection – Oral Antiviral Regimens

The CDC recommends oral acyclovir 400 mg three times daily for 7–10 days (or until lesions resolve) as first‑line therapy; valacyclovir 1 g twice daily or famciclovir 250 mg three times daily are equally effective alternatives offering more convenient dosing【1】.
Treatment should be continued beyond 10 days if clinical healing is incomplete【1】.

For patients with severe oral HSV‑1 disease or complications requiring hospitalization, the CDC advises intravenous acyclovir 5–10 mg/kg every 8 hours for 5–7 days (or until resolution)【3】.
Indications for IV therapy include disseminated HSV infection, central nervous system involvement (meningitis or encephalitis), pneumonitis, hepatitis, or inability to tolerate oral medication【3】.

Initiating therapy during the prodrome or within 1 day of lesion appearance shortens lesion duration; the CDC lists several effective oral regimens:
- Acyclovir 400 mg three times daily for 5 days【3】
- Acyclovir 200 mg five times daily for 5 days【3】
- Acyclovir 800 mg twice daily for 5 days【3】
- Valacyclovir 500 mg twice daily for 3–5 days【3】
- Famciclovir 125 mg twice daily for 5 days【3】
Patients should be provided with an antiviral prescription in advance so they can self‑initiate treatment at the first sign of prodrome【1】.

Daily suppressive therapy reduces recurrence frequency by ≥ 75 % in individuals experiencing ≥ 6 episodes per year【1】. Recommended regimens (CDC):
- Acyclovir 400 mg twice daily【3】
- Valacyclovir 500 mg twice daily (or 500–2000 mg twice daily for more severe disease)【3】
- Famciclovir 250 mg twice daily【3】
Long‑term safety has been documented for continuous acyclovir use up to 6 years and for valacyclovir/famciclovir up to 1 year; after one year, discontinuation should be considered to reassess recurrence frequency【1】.

These patients may require higher oral dosing: acyclovir 400 mg three to five times daily until complete clinical resolution【3】, with treatment duration extended beyond standard courses【3】.
Severe cases may need IV acyclovir 5 mg/kg every 8 hours【3】.
Famciclovir 500 mg twice daily has shown effectiveness in HIV‑infected individuals【3】.
Very high‑dose valacyclovir (8 g/day) has been linked to hemolytic‑uremic syndrome or thrombotic thrombocytopenic purpura in immunocompromised patients; standard therapeutic doses remain safe【3】.

Antiviral agents do not eradicate latent HSV and therefore cannot prevent future recurrences【4】.
Antivirals do not eliminate asymptomatic viral shedding, so transmission risk persists even without visible lesions【1】.

Asymptomatic shedding can occur, maintaining the potential for transmission【1】.
Recognized triggers for HSV‑1 reactivation include ultraviolet light exposure, fever, psychological stress, and hormonal changes associated with menstruation【5】.