What is the recommended treatment for herpes zoster?

Treatment of Herpes Zoster

For uncomplicated herpes zoster, initiate oral valacyclovir 1 gram three times daily for 7 days, which is the preferred first-line treatment due to superior bioavailability and convenient dosing compared to acyclovir. 1, 2

First-Line Oral Antiviral Options

Valacyclovir is the preferred agent for immunocompetent patients with uncomplicated herpes zoster 1, 2:

• Dosing: 1000 mg orally three times daily for 7 days 1, 3
• Advantages: Three- to five-fold better bioavailability than acyclovir, less frequent dosing, and significantly faster resolution of zoster-associated pain and postherpetic neuralgia compared to acyclovir 4, 5, 3
• Timing: Initiate within 72 hours of rash onset for optimal efficacy, though treatment beyond 72 hours may still provide benefit 1

Alternative oral options include 1, 6:

• Famciclovir: 500 mg orally three times daily for 7 days 6, 7
  • Similar efficacy to valacyclovir for acute zoster and postherpetic neuralgia 4, 7
  • FDA-approved dosing per label: 500 mg every 8 hours for 7 days 6
• Acyclovir: 800 mg orally five times daily for 7 days 1
  • Less convenient dosing schedule but effective alternative 1
  • Lower doses (200 mg five times daily) are inadequate for herpes zoster 8

Treatment Duration and Endpoint

Continue antiviral therapy until all lesions have completely scabbed, not just for an arbitrary 7-day period 1, 9:

• This is the key clinical endpoint that determines treatment completion 1
• Immunocompromised patients may require extended treatment beyond 7-10 days as lesions continue to develop for 7-14 days and heal more slowly 9
• If new lesions continue to form or healing is incomplete, extend treatment duration 1

Severe or Disseminated Disease

For disseminated, multi-dermatomal, ophthalmic, visceral, or complicated herpes zoster, initiate intravenous acyclovir immediately 1, 9:

• Dosing: 5-10 mg/kg IV every 8 hours 1, 2
• Duration: Continue for minimum 7-10 days and until clinical resolution is attained 1
• Transition: Switch to oral therapy once clinical improvement occurs to complete the treatment course 1
• Immunosuppression: Temporarily reduce or discontinue immunosuppressive medications in severe cases 1, 9

Special Populations

Immunocompromised Patients

All immunocompromised patients with herpes zoster require antiviral treatment regardless of timing 1:

• Consider intravenous acyclovir for severely immunocompromised hosts, particularly those on active chemotherapy 9
• Monitor closely for dissemination, visceral complications, and secondary infections 1, 2
• May require treatment extension well beyond 7-10 days due to prolonged lesion development and slower healing 9
• High-dose IV acyclovir (10 mg/kg every 8 hours) remains the treatment of choice for severely compromised hosts 9

HIV-Infected Patients

For recurrent orolabial or genital herpes in HIV-infected patients, use famciclovir 500 mg twice daily for 7 days 6:

• Higher oral doses may be needed for herpes zoster in HIV-positive patients 9
• Consider long-term acyclovir prophylaxis (400 mg 2-3 times daily) for frequent recurrences 9

Renal Impairment

Mandatory dose adjustments are required to prevent acute renal failure 9, 6:

• Valacyclovir/Acyclovir: Adjust based on creatinine clearance with close monitoring of renal function 9
• Famciclovir for herpes zoster 6:
  • 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

V1 (Ophthalmic) Distribution

Facial/ophthalmic zoster requires particular attention due to risk of vision-threatening complications 2:

• Initiate valacyclovir 1 gram three times daily immediately 2
• Consider ophthalmology consultation if ocular involvement is present 2
• Immunocompromised patients with V1 distribution should receive IV acyclovir 2

Acyclovir-Resistant Cases

For suspected acyclovir-resistant herpes zoster, switch to foscarnet 40 mg/kg IV every 8 hours 1, 9:

• Acyclovir-resistant isolates are routinely resistant to ganciclovir as well 1
• Requires close monitoring of renal function and electrolytes (hypocalcemia, hypophosphatemia, hypomagnesemia, hypokalemia) 1

Post-Exposure Prophylaxis

For varicella-susceptible patients exposed to active VZV infection 1, 9:

• First-line: Varicella zoster immunoglobulin (VZIG) within 96 hours of exposure 1, 9
• Alternative: If immunoglobulin unavailable or >96 hours have passed, give oral acyclovir for 7 days beginning 7-10 days after exposure 1, 9

Common Pitfalls to Avoid

• Do not use topical antiviral therapy as it is substantially less effective than systemic therapy 9
• Do not use acyclovir 400 mg three times daily for herpes zoster—this dose is only appropriate for genital herpes or HSV suppression, not shingles 9
• Do not rely on arbitrary 7-day treatment duration—continue until all lesions have scabbed 1, 9
• Do not delay treatment in immunocompromised patients waiting for the 72-hour window—treat immediately regardless of timing 1
• Do not use oral therapy alone for severe cases in immunocompromised patients—escalate to IV acyclovir 2

Prevention

The recombinant zoster vaccine (Shingrix) is recommended for all adults aged 50 years and older, regardless of prior herpes zoster episodes 1, 9:

• Preferred over live-attenuated vaccine (Zostavax), which is contraindicated in immunocompromised patients 9
• Ideally administer before initiating immunosuppressive therapies 9
• Can be given after recovery from acute herpes zoster to prevent future episodes 9