Version July 2025
GVHD: graft-versus-host disease; HCT: hematopoietic cell transplant; IV: intravenously; PO: orally.
* There is no specific age cut off to decide when someone who presents after 72 hours may benefit from treatment. However, immunity to varicella-zoster virus (VZV) wanes with increasing age and can be severely impaired in those of advanced age.
¶ For nonpregnant patients who warrant oral therapy, we prefer treatment with valacyclovir or famciclovir because of their lower dosing frequency compared with acyclovir. For pregnant patients, we prefer acyclovir since there is the most experience with this medication in pregnancy. Treatment should continue until all lesions have crusted (typically 7 days for immunocompetent patients; 7 to 14 days for immunocompromised patients).
Δ For most patients at high risk for dissemination, we initiate intravenous acyclovir. Patients can switch to an oral agent after clinical improvement; treatment should continue until all lesions have crusted (typically 7 to 14 days). It is reasonable to initiate oral therapy for severely immunocompromised patients with mild herpes zoster; however, transition to IV acyclovir is required if new vesicle formation continues despite several days of oral therapy and/or other signs and symptoms of systemic involvement develop.
◊ Dosing in this inset is intended for adult patients with normal kidney and liver function. For dose adjustments, refer to drug information topics within UpToDate.
