Treatment for Shingles (Herpes Zoster)
For uncomplicated shingles, initiate oral antiviral therapy with valacyclovir 1 gram three times daily or famciclovir 500 mg three times daily for 7-10 days, continuing until all lesions have completely scabbed. 1
First-Line Oral Antiviral Options
The three FDA-approved oral antivirals are equally effective, but differ in dosing convenience:
- Valacyclovir 1 gram three times daily for 7 days is the preferred first-line agent due to superior bioavailability and convenient dosing 2, 1
- Famciclovir 500 mg three times daily for 7 days offers equivalent efficacy with three-times-daily dosing 3, 1
- Acyclovir 800 mg five times daily for 7-10 days remains effective but requires more frequent dosing, which may reduce adherence 1, 2
Critical timing: Antiviral therapy must be initiated within 72 hours of rash onset for optimal efficacy in reducing acute pain, accelerating lesion healing, and preventing postherpetic neuralgia 1. Treatment is most effective when started within 48 hours 1, 4.
Treatment Duration and Endpoint
- Continue antiviral therapy until all lesions have completely scabbed, not just for an arbitrary 7-day period 1
- Do not discontinue at exactly 7 days if lesions are still forming or have not completely scabbed 1
- Immunocompromised patients may require treatment extension well beyond 7-10 days as their lesions continue to develop over longer periods (7-14 days) and heal more slowly 1
Indications for Intravenous Acyclovir
Switch to IV acyclovir 10 mg/kg every 8 hours for:
- Disseminated or invasive herpes zoster (multi-dermatomal, visceral involvement) 1, 5
- Severely immunocompromised patients (e.g., active chemotherapy, HIV with low CD4 count) 1
- Complicated facial zoster with suspected CNS involvement or severe ophthalmic disease 1
- Patients who cannot tolerate oral medications 6
Continue IV therapy for a minimum of 7-10 days and until clinical resolution is attained 1, 5.
Special Population Considerations
Immunocompromised patients:
- Require immediate IV acyclovir due to high risk of dissemination and complications 1
- Consider temporary reduction in immunosuppressive medications for disseminated disease 1
- Monitor closely for acyclovir resistance if lesions persist despite treatment 1
Renal impairment:
- Dose adjustments are mandatory to prevent acute renal failure 1
- Monitor renal function at initiation and once or twice weekly during IV therapy 1
Facial/ophthalmic involvement:
- Requires particular urgency given risk of vision-threatening complications and cranial nerve involvement 1
- Consider ophthalmology referral for zoster ophthalmicus 7, 4
Adjunctive Pain Management
- Appropriately dosed analgesics in combination with neuroactive agents (e.g., amitriptyline) should be given together with antiviral therapy 4
- Corticosteroids (prednisone) may provide modest benefits in reducing acute zoster pain but do not prevent postherpetic neuralgia 7, 8
- Corticosteroids should generally be avoided in immunocompromised patients due to increased risk of disseminated infection 1
Critical Pitfalls to Avoid
- Topical antivirals are substantially less effective than systemic therapy and are not recommended 1
- Do not use acyclovir 400 mg three times daily—this dose is only appropriate for genital herpes, not shingles 1
- Do not rely on short-course therapy designed for genital herpes, as it is inadequate for VZV infection 1
- Antiviral medications do not eradicate latent virus but help control symptoms and reduce complications 1
Infection Control
- Patients should avoid contact with susceptible individuals (those who have not had chickenpox or vaccination) until all lesions have crusted 1, 6
- Lesions are contagious and can transmit varicella to susceptible individuals 6, 5