Herpes Simplex Virus Disease (Outside Neonatal Period)

Herpes simplex encephalitis or other disseminated disease regardless of immune status, including suspected HSV encephalitis pending diagnostic evaluation 

See guidance on HSV disease  in neonates and young infants < 3 months old 

Age 3 months to < 12 years: 

Acyclovir
15 mg/kg/dose IV q8h 

>=12 years: 

Acyclovir
10 mg/kg/dose IV q8h 

ID consult recommended 

Duration: 21 days 

Some experts may recommend suppressive oral acyclovir following acute treatment of HSV encephalitis in infants 3-12 months of age. Consult ID and refer to neonatal guidelines for suppressive dosing if recommended 

Acyclovir
20 mg/kg/dose (max 800 mg/dose) enterally tid 

OR 

Valacyclovir
20 mg/kg/dose (max 1000 mg/dose) enterally bid 

For patients unable to tolerate enteral therapy: 

Acyclovir
5 mg/kg/dose IV q8h 

Enteral therapy is preferred if possible. IV therapy increases risk for nephrotoxicity due to crystal nephropathy with greater risk associated with dehydration, higher dose and faster rate of infusion. If IV therapy is given, ensure good hydration status 

Transition to enteral therapy as soon as possible 

Episodic treatment most likely to be beneficial if initiated within 72 hours of onset 

Duration: Usually 5-7 days, dependent on clinical resolution; though may treat with single day (2 dose) duration with valacyclovir in adolescents 

Chronic suppressive therapy may be considered for patients experiencing 6+ outbreaks/year 

Initial IV therapy for patients at high risk for progression or with severe symptoms or impaired enteral intake: 

Acyclovir
10 mg/kg/dose IV q8h 

Transition to enteral therapy when patient shows clinical improvement and is able tolerate enteral treatment 

Enteral therapy for patients with mild-moderate symptoms, low risk for progression:  

Acyclovir
20 mg/kg/dose (max 800 mg/dose) enterally tid 

OR 

Valacyclovir
20 mg/kg/dose (max 1000 mg/dose) enterally bid 

Consider ID consult 

In immuno-compromised host, start treatment as soon as possible (based on clinical suspicion) and regardless of days elapsed since onset  

Duration: Until complete healing of the lesions, generally 7-14 days 

Herpes simplex genital infection in adolescents, first episode 

Valacyclovir
1000 mg enterally bid  

OR 

Acyclovir
800 mg enterally tid 

First reported episode of genital lesions is suggestive of primary infection, treatment is generally indicated and should be started as soon as possible and regardless of days elapsed since onset 

Duration: 7-10 days. Treatment can be extended until complete healing of lesions. Starting suppressive therapy may be considered after first episode, and is indicated starting at 36 weeks gestation in pregnant patients (see below) 

For patients who are pregnant and near delivery, further distinction of primary vs non primary infection should be made via lab testing to guide management of neonate, refer to published guidelines 

Herpes simplex genital infection in adolescents, prevention or treatment of recurrent episodes 

Suppressive therapy, non-pregnant patient: 

Acyclovir
400 mg enterally bid 

OR  

Valacyclovir
1000 mg enterally daily 

Suppressive therapy,  pregnant patient: 

Acyclovir
400 mg enterally tid 

OR  

Valacyclovir
1000 mg enterally daily 

Episodic therapy for non-primary infection:  

Acyclovir
800 mg enterally tid  

OR 

Valacyclovir
1000 mg/dose enterally daily  

Duration: 

Suppressive therapy for 6-12 months following first episode may prevent recurrence and improve quality of life, and decrease risk of transmission to sexual partners.  

Suppressive therapy is also indicated for pregnant patients with history of genital HSV beginning at 36 weeks gestation. 

Alternatively, episodic treatment of recurrent episodes may be used. Initiate therapy within 1 day of lesion onset or during prodrome for 5 days