Use actual body weight to calculate weight-based dosing. Follow obesity dosing below if:
HSV:
Genital (primary or nonprimary episode):
200 mg PO 5 times per day x 5-10 days
Recurrent Genital Lesions:
200 mg PO 5 times per day x 5 days
OR
800 mg PO TID x 2 days
Initiate at onset of symptoms
Herpes labialis:
200-400 mg PO 5 times per day x 5 days
Unable to take oral or severe mucocutaneous infection: 5 mg/kg IV Q8H
(Switch to oral once improved).
Serious Infections
(e.g. CNS and Disseminated): 10mg/kg IV q8h
VZV/Zoster:
Chicken Pox in Adulthood:
800mg PO QID x 5 days
Shingles:
800 mg 5 times per day x 7-10 days
Serious Infections
(e.g. CNS and Disseminated)
10-15 mg/kg IV q8h (higher doses typically reserved in HIV/immune compromise - see full guidelines or consult ID for details)
Prophylaxis dosing varies by indication refer to specific treatment guidelines.
See Canadian Guidelines on Sexually Transmitted Infections for full management recommendations for HSV.
Obesity
Use adjusted body weight (ABW) for patients with obesity (weight is 30% or more above IBW or BMI 30 kg/m2 and above) in order to avoid overdosing and potential toxicity.
ABW = (IBW + 0.4x[TBW-IBW])