What is the recommended treatment for herpes zoster?

Treatment of Herpes Zoster (Shingles)

First-Line Antiviral Therapy

For uncomplicated herpes zoster, initiate oral valacyclovir 1 gram three times daily for 7 days, starting within 72 hours of rash onset when possible. 1

• Valacyclovir 1 gram orally three times daily for 7 days is the recommended first-line treatment for uncomplicated herpes zoster 1, 2
• Alternative oral options include:
  • Acyclovir 800 mg orally five times daily for 7 days 1
  • Famciclovir 500 mg orally every 8 hours for 7 days 1, 3
• Treatment is most effective when initiated within 48-72 hours of rash onset, though delayed initiation beyond 72 hours may still provide benefit 1
• Continue treatment until all lesions have completely scabbed, not just for an arbitrary 7-day period—this is the key clinical endpoint 1, 2

When to Escalate to Intravenous Therapy

Intravenous acyclovir 5-10 mg/kg every 8 hours is required for disseminated, multi-dermatomal, ophthalmic, visceral, or complicated herpes zoster. 1

• Indications for IV therapy include:
  • Disseminated or invasive herpes zoster 1, 2
  • Multi-dermatomal involvement 1
  • Ophthalmic or facial involvement with suspected CNS complications 1
  • Visceral organ involvement 2
  • Immunocompromised patients with severe disease 1
• Continue IV treatment for a minimum of 7-10 days and until clinical resolution is attained 1
• Switch to oral therapy once clinical improvement occurs 1
• Consider temporary reduction in immunosuppressive medications if applicable 1, 2

Special Populations

Immunocompromised Patients

• All immunocompromised patients with herpes zoster require antiviral treatment regardless of timing 1
• Consider IV acyclovir for severely immunocompromised hosts due to high risk of dissemination 1, 2
• Monitor closely for dissemination and visceral complications 1
• May require treatment extension well beyond 7-10 days as lesions continue to develop over longer periods (7-14 days) and heal more slowly 2
• Without adequate antiviral therapy, some immunocompromised patients develop chronic ulcerations with persistent viral replication 2

HIV-Infected Patients

• Recurrent orolabial or genital herpes in HIV-infected patients: famciclovir 500 mg twice daily for 7 days 3
• Higher oral doses may be needed for herpes zoster (up to 800mg 5-6 times daily) 2
• Consider long-term acyclovir prophylaxis (400mg 2-3 times daily) 2

Ramsay Hunt Syndrome (Herpes Zoster Oticus)

• Initiate valacyclovir 1 gram three times daily for 7 days PLUS systemic corticosteroids as soon as possible, ideally within 72 hours 4
• This presentation involves vesicles on the external ear canal and posterior auricle, severe otalgia, facial paralysis, loss of taste, and decreased lacrimation 4
• Do not delay treatment waiting for laboratory confirmation—diagnosis is clinical 4
• Systemic therapy is mandatory; topical antivirals are inadequate 4

Acyclovir-Resistant Cases

For suspected acyclovir-resistant herpes zoster, foscarnet 40 mg/kg IV every 8 hours is required. 1, 2

• Acyclovir-resistant isolates are routinely resistant to ganciclovir as well 1
• Monitor for resistance if lesions persist despite adequate treatment 2

Renal Dose Adjustments

Critical adjustments are mandatory to prevent acute renal failure 2:

Famciclovir dosing for herpes zoster by creatinine clearance: 3

• CrCl ≥60 mL/min: 500 mg every 8 hours
• CrCl 40-59 mL/min: 500 mg every 12 hours
• CrCl 20-39 mL/min: 500 mg every 24 hours
• CrCl <20 mL/min: 250 mg every 24 hours
• Hemodialysis: 250 mg following each dialysis

Monitor renal function closely during IV acyclovir therapy with dose adjustments as needed 2

Pain Management

• Appropriately dosed analgesics in combination with a neuroactive agent (e.g., amitriptyline) should be given together with antiviral therapy 5
• For severe acute pain, consider systemic corticosteroids as adjunctive therapy in select cases, though this does not prevent postherpetic neuralgia 2, 5
• Avoid corticosteroids in immunocompromised patients due to increased risk of disseminated infection 2

Prevention

The recombinant zoster vaccine (Shingrix) is recommended for all adults aged 50 years and older, regardless of prior herpes zoster episodes. 1, 2

• Vaccination should ideally occur before initiating immunosuppressive therapies 2
• The recombinant vaccine can be considered after recovery to prevent future episodes 2
• Live-attenuated vaccines (Zostavax) are contraindicated in immunocompromised patients 2

Critical Pitfalls to Avoid

• Do not rely on topical antiviral therapy—it is substantially less effective than systemic therapy and is not recommended 2
• Do not stop treatment at 7 days if lesions remain active—continue until all lesions have completely scabbed 1, 2
• Do not delay treatment beyond 72 hours when possible—effectiveness decreases with delayed initiation 1
• Do not use standard HSV dosing for herpes zoster—400mg TDS is only appropriate for genital herpes, not shingles 2
• Do not confuse with acute otitis externa when evaluating ear involvement—look for vesicles, facial paralysis, and severe pain suggesting Ramsay Hunt syndrome 4

Infection Control

Patients with shingles should avoid contact with susceptible individuals (those who have not had chickenpox) until all lesions have crusted, as lesions are contagious 2