Below are suggested duration of therapy. Actual duration depends on clinical response.

Infection Acyclovir Valacyclovir
Acyclovir available as:
200mg, 400mg and 800mg tabs
40mg/mL suspension

Valacyclovir available as:
500mg, 1000mg tabs

* only 500mg tabs are covered under ODB
Orolabial Herpes (HSV) Immunocompetent / immunocompromised:
Acyclovir
IV: 5mg/kg IV q8h
PO: 400mg 5x/day OR 800mg TID x 5 days		Valacyclovir 2g BID x 1 day

Duration in immunocompromised patients 5-10 days
Genital Herpes Initial Episode:
Acyclovir 200mg 5x/daily x 5–10 days
* CDC recommends acyclovir 400mg TID for 7-10 days

Recurrent episodes:
800mg po TID x 2 days
OR
400mg po TID x 5 days

(HIV patients: 400mg dosing regimen for 5 –10 days) 		Primary Episode:
Valacyclovir 1g BID x 10 days

Recurrent episodes:
500mg BID
OR
1 gram DAILY x 3 days

Duration in immunocompromised patients 5-10 days
Severe HSV
(including encephalitis) 		Acyclovir:
10mg/kg IV q8h (encephalitis x 21 days)

Neonates:
20mg/kg IV q8h
Children 3 months to < 12 years of age: 10-15mg/kg IV q8h
Chicken pox
(Varicella)
VZV 		Immunocompetent:
Acyclovir
Severe infection:
IV: 10mg/kg IV q8h (x 5 days; duration based on clinical response)PO: 800mg 5x/day (x 5 days; duration based on clinical response)

Immunocompromised:
Acyclovir
Severe:
IV: 10mg/kg IV q8h (x 7 days; Consider extended course if lesions are slow to heal) 		Immunocompetent:
Valacyclovir
PO: 1g TID x 5 days

Immunocompromised:
Valacyclovir
PO: 1g TID x 7 days
(Consider extended course if lesions are slow to heal)

*refer to MacPeds Pediatric Formulary for pediatric dosing of valacyclovir
Shingles
(Herpes Zoster) 		Immunocompetent:
Acyclovir
IV: 10mg/kg IV q8h x 7-10 days
PO: 800mg 5x/day x 7-10 days

Immunocompromised:
Acyclovir
Severe: 10mg/kg IV q8h
Therapy should continue until lesions have completely healed

Non-severe: 800mg 5x/day x 7 days 		Immunocompetent:
Valacyclovir
PO: 1g TID x 7 days

Immunocompromised:
Severe: Start with IV acyclovir, step down to oral valacyclovir when lesions have begun to regress

All adult acyclovir IV dosing should be calculated based on ideal body weight. IV administration should be used for severe infections or complications, infections during pregnancy, neonatal infections, immunocompromised patients (HIV), and patients with hypersensitivities to oral ingredients.