Treatment of Shingles
For immunocompetent adults with shingles, valacyclovir 1 gram three times daily for 7 days is the preferred first-line treatment, offering superior pain reduction and more convenient dosing compared to acyclovir. 1, 2
First-Line Antiviral Options
The FDA-approved regimens for herpes zoster include:
- Valacyclovir 1 gram orally three times daily for 7 days - This is the optimal choice based on superior efficacy in reducing zoster-associated pain (36% risk reduction at 21-30 days, NNT=3) and convenient dosing schedule 1, 2
- Famciclovir 500 mg orally three times daily for 7 days - Comparable efficacy to valacyclovir with 46% pain reduction at 28-30 days (NNT=3), making it an excellent alternative 2
- Acyclovir 800 mg orally five times daily for 7 days - Effective but requires more frequent dosing (five times daily), which reduces compliance 3, 4
Initiate treatment within 72 hours of rash onset for maximum benefit, though evidence suggests valacyclovir may still be effective when started later 1, 5. Treatment is most effective when started within 48 hours 6, 4.
Key Treatment Principles
Timing and Duration
- Start antiviral therapy at the earliest sign or symptom of herpes zoster 1
- Standard 7-day treatment is sufficient; extending to 14-21 days provides no additional benefit in preventing postherpetic neuralgia 5, 7
- Monitor for complete lesion resolution; extend treatment if healing is incomplete after initial course 3
Pain Management Considerations
- Valacyclovir and famciclovir significantly accelerate resolution of acute pain and reduce duration of postherpetic neuralgia compared to acyclovir 5, 2
- The addition of oral corticosteroids (prednisolone 40 mg daily, tapered over 3 weeks) provides only modest short-term pain reduction during acute phase but does NOT prevent postherpetic neuralgia 7
Special Populations
Immunocompromised Patients
These patients require more aggressive management:
- Intravenous acyclovir 5-10 mg/kg every 8 hours for severe disease or complications (disseminated infection, pneumonitis, hepatitis, CNS involvement) 8, 9
- Continue IV therapy until clinical resolution is attained, which may require prolonged treatment duration 8, 9
- Consider discontinuing immunosuppressive therapy in severe cases of disseminated herpes zoster 3
Pediatric Patients (Chickenpox)
- For immunocompetent children aged 2 to <18 years: 20 mg/kg three times daily for 5 days (maximum 1 gram per dose) 1
Herpes Zoster Ophthalmicus
- Use standard valacyclovir or acyclovir dosing as above 5
- Requires ophthalmology referral due to risk of serious ocular complications 6
Critical Pitfalls to Avoid
- Never use topical acyclovir - it is substantially less effective than oral therapy and should not be used 3
- Do not underdose or shorten treatment duration - this leads to treatment failure and increased complication risk 3
- Do not delay treatment in immunocompromised patients - they require immediate aggressive therapy with IV acyclovir for severe presentations 3, 8
- Do not rely on corticosteroids alone - they provide only modest acute pain relief without preventing postherpetic neuralgia 7
Patient Education and Infection Control
- Lesions are contagious to individuals who have not had chickenpox - patients must avoid contact with susceptible individuals (pregnant women, immunocompromised persons, infants) until all lesions have crusted over 8, 9
- Advise that antiviral therapy reduces pain duration and severity but does not eliminate risk of postherpetic neuralgia 6, 5
Adverse Effects
All three antivirals are generally well-tolerated with similar safety profiles 5, 2: