Herpes Zoster Treatment
For immunocompetent adults with herpes zoster, initiate oral valacyclovir 1 g three times daily or famciclovir 500 mg three times daily for 7 days within 72 hours of rash onset, as these provide superior pain reduction compared to acyclovir.
Antiviral Therapy
Immunocompetent Patients
First-line treatment options (start within 72 hours of rash onset):
- Valacyclovir 1 g orally three times daily for 7 days 1
- Famciclovir 500 mg orally three times daily for 7 days 1
- Acyclovir 800 mg orally five times daily for 7 days 2
Valacyclovir and famciclovir demonstrate 36-46% reduction in herpes zoster-associated pain at 21-30 days compared to acyclovir, with number needed to treat of 3. Their superior pharmacokinetics and convenient dosing (three times daily vs. five times daily) make them preferred options 1.
Immunocompromised Patients
Immunocompromised patients require more aggressive therapy due to risk of dissemination and prolonged disease 3:
- Localized disease: Oral valacyclovir, famciclovir, or acyclovir with close outpatient monitoring 3
- Severe disease or dissemination risk: IV acyclovir 10 mg/kg every 8 hours for 7-10 days 4
- Acyclovir-resistant strains: Foscarnet 40 mg/kg IV every 8 hours until clinical resolution 4
Immunocompromised patients may require longer treatment courses and should be monitored closely for complications including dissemination, organ involvement, and treatment failure 5.
Pain Management
Acute Pain
Initiate early antiviral therapy combined with appropriate analgesics to reduce acute zoster pain and prevent postherpetic neuralgia 3:
- Mild to moderate pain: NSAIDs
- Moderate to severe pain: Opioids as needed
- Neuropathic component: Consider pregabalin or gabapentin early 6
Postherpetic Neuralgia (PHN)
PHN develops in 10-20% of cases overall and up to 50% in patients over 85 years 6:
- First-line: Pregabalin or gabapentin (anticonvulsants)
- Second-line: Tricyclic antidepressants
- Topical: Lidocaine patches or capsaicin cream
- Refractory cases: Interventional pain procedures 6
Special Populations
Ophthalmic Involvement
Requires immediate ophthalmology consultation. Use higher doses of acyclovir (400 mg orally five times daily) or equivalent doses of valacyclovir/famciclovir 4.
Severe Disease Requiring Hospitalization
IV acyclovir 5-10 mg/kg every 8 hours for complications including:
- Disseminated infection
- Encephalitis
- Pneumonitis
- Hepatitis 4
Renal Impairment
Brivudine (125 mg once daily, where available) does not require renal dose adjustment and may be preferred in elderly patients with renal impairment 7.
Critical Timing Considerations
Treatment must begin within 72 hours of rash onset for maximum efficacy in preventing complications and reducing pain duration 2, 1. However, initiate antiviral therapy in immunocompromised patients at any time before full crusting of lesions 3.
Common Pitfalls to Avoid
- Do not use topical acyclovir - substantially less effective than oral therapy 8
- Do not delay treatment waiting for laboratory confirmation in typical presentations
- Do not underdose immunocompromised patients - they require higher doses and longer duration
- Do not assume oral therapy is adequate for disseminated disease or severe immunosuppression
- Do not overlook pain management - early aggressive pain control reduces PHN risk
Prevention
For adults ≥50 years, recombinant zoster vaccine (Shingrix) is highly effective in preventing both herpes zoster and postherpetic neuralgia 6. Vaccination should be discussed with all eligible patients, particularly those at increased risk including women, elderly, and immunocompromised individuals 9.