Treatment of Shingles (Herpes Zoster)
For immunocompetent adults with shingles, initiate oral antiviral therapy with valacyclovir 1000 mg three times daily for 7 days, acyclovir 800 mg five times daily for 7-10 days, or famciclovir 500 mg every 8 hours for 7 days, starting as soon as possible after diagnosis and continuing until all lesions have scabbed. 1, 2
First-Line Oral Antiviral Options
The three FDA-approved oral antivirals are equally effective for treating acute shingles, but differ in dosing convenience:
Valacyclovir 1000 mg orally three times daily for 7 days offers superior bioavailability compared to acyclovir and has been shown to accelerate resolution of zoster-associated pain faster than acyclovir (median 38 days vs 51 days), while also reducing postherpetic neuralgia duration 3, 4
Acyclovir 800 mg orally five times daily for 7-10 days is the traditional standard therapy, though the five-times-daily dosing may reduce adherence 2, 5
Famciclovir 500 mg orally every 8 hours for 7 days provides three-times-daily dosing convenience and has demonstrated significant reduction in postherpetic neuralgia duration (median reduction of 100 days in patients ≥50 years) 6, 7
Critical Timing Considerations
Initiate treatment as soon as herpes zoster is diagnosed, ideally within 72 hours of rash onset for maximum efficacy 1, 6, 2
Treatment initiated beyond 72 hours may still provide benefit for pain reduction, though this is less well-established 4
Continue antiviral therapy until all lesions have completely scabbed, which is the key clinical endpoint—not an arbitrary 7-day duration 1
If lesions remain active beyond 7 days, extend treatment duration until complete crusting occurs 1
Special Populations and Severe Disease
Immunocompromised Patients
For disseminated or invasive herpes zoster, use intravenous acyclovir 5-10 mg/kg every 8 hours until clinical resolution is achieved 1, 8
Consider temporary reduction in immunosuppressive medications when treating disseminated disease 1
High-dose IV acyclovir remains the treatment of choice for VZV infections in severely compromised hosts 1
Renal Impairment
Dose adjustments are mandatory to prevent acute renal failure 6, 2
For acyclovir with creatinine clearance 10-25 mL/min: reduce to 800 mg every 8 hours 2
For acyclovir with creatinine clearance 0-10 mL/min: reduce to 800 mg every 12 hours 2
Monitor renal function closely during IV acyclovir therapy, with dose adjustments as needed 1
Important Caveats and Pitfalls
Topical antiviral therapy is substantially less effective than systemic therapy and should not be used 1
Patients with shingles should avoid contact with individuals who have not had chickenpox until all lesions are crusted, as the lesions are contagious 1, 8
In immunocompromised patients receiving high-dose therapy, assess for thrombotic thrombocytopenic purpura/hemolytic uremic syndrome 1
Valacyclovir at doses of 8 g per day has been associated with hemolytic uremic syndrome/thrombotic thrombocytopenic purpura in immunocompromised patients and should be avoided 9
Adjunctive Considerations
Corticosteroids (prednisone) may be considered as adjunctive therapy in select cases of severe, widespread shingles, but should generally be avoided in immunocompromised patients due to increased risk of disseminated infection 1
For facial zoster, elevation of the affected area and keeping skin well hydrated with emollients is recommended to prevent complications 1
Prevention
The recombinant zoster vaccine (Shingrix) is recommended for all adults aged 50 years and older, regardless of prior herpes zoster episodes 1
Vaccination should ideally occur before initiating immunosuppressive therapies 1
The vaccine can be considered after recovery from an acute episode to prevent future recurrences 1