Treatment of Shingles (Herpes Zoster)
For uncomplicated shingles, start oral valacyclovir 1 gram three times daily or famciclovir 500 mg three times daily within 72 hours of rash onset, continuing for 7-10 days until all lesions have completely scabbed. 1, 2, 3
First-Line Oral Antiviral Therapy
Preferred agents for immunocompetent patients with uncomplicated herpes zoster:
- Valacyclovir 1 gram three times daily for 7-10 days 1, 2
- Famciclovir 500 mg three times daily for 7 days 1, 3
- Acyclovir 800 mg five times daily for 7-10 days (effective but requires more frequent dosing) 1
Valacyclovir and famciclovir offer superior bioavailability and more convenient dosing schedules compared to acyclovir, potentially improving adherence 1, 4. All three agents are equally effective in shortening viral shedding, accelerating lesion healing by 1-2 days, and reducing acute pain intensity 4, 5.
Critical Timing and Duration
Initiate treatment within 72 hours of rash onset for optimal efficacy in reducing acute pain, accelerating healing, and preventing postherpetic neuralgia 1, 5. Treatment is most effective when started within 48 hours 1.
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.
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
- Severely immunocompromised patients 1, 6
- Complicated facial zoster with suspected CNS involvement 1
- Severe ophthalmic disease 1
- Patients on active chemotherapy or with conditions like multiple myeloma 1
For immunocompromised patients with disseminated disease, consider temporary reduction in immunosuppressive medications 1.
Special Populations Requiring Urgent Treatment
Mandatory antiviral therapy regardless of timing:
- Patients ≥50 years of age 5
- Herpes zoster in the head and neck area, especially zoster ophthalmicus 5
- Immunosuppressed patients at any age 1, 5
- Severe herpes zoster on trunk or extremities 5
- Patients with severe atopic dermatitis or eczema 5
Relative indications for antiviral therapy exist in patients younger than 50 years with uncomplicated zoster on the trunk and extremities 5.
Pain Management
Appropriately dosed analgesics combined with a neuroactive agent (such as amitriptyline) should be given together with antiviral therapy to achieve painlessness 5. The addition of oral corticosteroids may provide modest benefits in reducing acute zoster pain but has no essential effect on preventing postherpetic neuralgia 7, 5.
Avoid corticosteroids in immunocompromised patients due to increased risk of disseminated infection 1.
Monitoring and Follow-Up
- Monitor renal function at initiation and once or twice weekly during IV acyclovir therapy, with dose adjustments for renal impairment 1, 6
- If lesions fail to begin resolving within 7-10 days, suspect acyclovir resistance and obtain viral culture with susceptibility testing 1
- For acyclovir-resistant cases, foscarnet 40 mg/kg IV every 8 hours is the treatment of choice 1
Infection Control
Patients should avoid contact with susceptible individuals (those who have not had chickenpox) until all lesions have crusted, as lesions are contagious 1, 6.
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.
Common Pitfalls to Avoid
- Do not use topical antivirals - they are substantially less effective than systemic therapy 1
- Do not delay treatment beyond 72 hours waiting for "confirmation" - clinical diagnosis is sufficient in immunocompetent patients 1
- Do not stop treatment at exactly 7 days if lesions have not completely scabbed 1
- Do not underdose - short-course therapy designed for genital herpes (e.g., acyclovir 400 mg TDS) is inadequate for VZV infection 1