Treatment of Shingles (Herpes Zoster)
Start oral antiviral therapy with valacyclovir 1 gram three times daily for 7 days, ideally within 72 hours of rash onset, for all immunocompetent patients over 50 years of age and those with involvement of the head/neck region. 1
Antiviral Therapy Selection
First-Line Options for Immunocompetent Patients
The three FDA-approved oral antivirals are equally effective and well-tolerated for shingles treatment 2, 3:
Valacyclovir 1 gram three times daily for 7 days - This is the standard regimen with proven efficacy in reducing acute pain and postherpetic neuralgia duration 1, 3
Famciclovir 500 mg three times daily for 7 days - Comparable efficacy to valacyclovir with similar time to lesion crusting and pain resolution 4, 3
Acyclovir 800 mg five times daily for 7 days - Effective but requires more frequent dosing, which may reduce compliance 5, 2
All three agents demonstrate similar safety profiles, with nausea and headache being the most common side effects 6, 3. Valacyclovir and famciclovir offer superior dosing convenience (three times daily versus five times daily for acyclovir), which enhances patient adherence 7, 2.
Timing of Treatment Initiation
Treatment should be initiated within 48-72 hours of rash onset for maximum benefit 1, 5, 2. However, observational data suggest that starting valacyclovir beyond 72 hours may still provide benefit for pain reduction, so treatment should not be withheld in late presenters 3.
Specific Indications for Antiviral Therapy
Urgent Indications (Treatment Mandatory)
- All patients ≥50 years of age - This population has the highest risk of postherpetic neuralgia 2, 8
- Herpes zoster ophthalmicus or any head/neck involvement - Risk of serious ocular and neurological complications 2
- Immunocompromised patients at any age 9, 2
- Severe disease on trunk or extremities 2
Relative Indications
- Patients <50 years with uncomplicated trunk or extremity involvement have less clear benefit but may still be treated 2
Management of Immunocompromised Patients
For immunocompromised patients with severe disease or complications, use intravenous acyclovir 5-10 mg/kg every 8 hours and continue treatment until clinical resolution is achieved 6, 9. This may require prolonged therapy beyond the standard 7-day course 9.
Pain Management
Adequate analgesia is essential and should be initiated concurrently with antiviral therapy 2:
- Use appropriately dosed analgesics (including narcotics if needed for severe pain) 5, 2
- Consider adding a neuroactive agent such as amitriptyline early in the course 2
- Tricyclic antidepressants or anticonvulsants in low doses help control neuropathic pain 5
- Topical agents (capsaicin, lidocaine patches) can be used as adjuncts 5
Role of Corticosteroids
Oral corticosteroids added to antiviral therapy may provide modest reduction in acute zoster pain but do not significantly prevent postherpetic neuralgia 5, 2. Their use should be considered on a case-by-case basis.
Patient Education and Precautions
Patients must be counseled that lesions are contagious to individuals who have not had chickenpox until all lesions have crusted over 6, 9. They should avoid contact with susceptible individuals (pregnant women, immunocompromised persons, infants) during this period 9.
Common Pitfalls to Avoid
- Do not withhold treatment in patients presenting after 72 hours - Evidence suggests benefit may still occur, particularly for pain reduction 3
- Do not undertreate pain - Aggressive early pain management may prevent chronic postherpetic neuralgia 2
- Do not miss zoster ophthalmicus - Any periocular involvement warrants ophthalmology referral 5, 2
- Do not use inadequate antiviral dosing - Ensure full therapeutic doses are prescribed for the complete 7-day course 1, 4
Special Considerations
Postherpetic neuralgia occurs in approximately 30% of patients at 6 weeks, declining to 9% at one year 8. Age and severity of initial pain are the strongest predictors of persistent pain beyond 3 months 8. Early aggressive treatment with antivirals significantly reduces both the duration and severity of this complication 7, 3.