What is the recommended treatment for reoccurring herpes zoster (shingles)?

Treatment for Recurrent Herpes Zoster (Shingles)

For recurrent herpes zoster (shingles), the recommended treatment is famciclovir 500 mg every 8 hours for 7 days, initiated as soon as shingles is diagnosed. 1

First-Line Antiviral Therapy

Antiviral medications are the cornerstone of treatment for recurrent shingles. The FDA-approved options include:

• Famciclovir: 500 mg every 8 hours for 7 days 1
• Valacyclovir: 1000 mg three times daily for 7 days 2
• Acyclovir: 800 mg five times daily for 7 days 3

These medications are most effective when started within 72 hours of rash onset, but treatment should still be initiated even if beyond this window, as it may still provide benefit 2.

Dosing Adjustments for Renal Impairment

For patients with renal impairment, dosage adjustments are necessary:

Famciclovir dosing for herpes zoster 1:

• 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

Management of Resistant Cases

If lesions do not begin to resolve within 7-10 days of starting therapy:

1. Suspect acyclovir-resistant HSV
2. Obtain viral culture and susceptibility testing
3. For confirmed resistant cases, consider alternative treatments:
   • Intravenous foscarnet (40 mg/kg three times daily or 60 mg/kg twice daily) 4
   • Topical trifluridine (TFT) for accessible lesions 4
   • Cidofovir (intravenous or topical) as a last resort 4

Special Considerations

Immunocompromised Patients

• HIV-infected patients should receive higher doses: 500 mg twice daily for 7 days for famciclovir 1
• More aggressive treatment may be needed as these patients are at higher risk for disseminated disease and complications 4

Pain Management

For post-herpetic neuralgia (PHN), which can persist after resolution of the rash:

• Tricyclic antidepressants or anticonvulsants in low dosages for neuropathic pain 5
• Narcotics may be required for adequate pain control in severe cases 5
• Capsaicin, lidocaine patches, and nerve blocks can be used in selected patients 5

Patient Education and Follow-up

• Patients should be educated about the natural history of shingles and potential for recurrent episodes 6
• Follow-up within 72 hours of initiating therapy to assess response 6
• Continue follow-up until complete resolution of lesions 6
• Monitor for complications such as secondary bacterial infection 6

Common Pitfalls to Avoid

1. Delayed treatment: Initiating antiviral therapy beyond 72 hours reduces efficacy, though treatment should still be given 2
2. Inadequate pain management: Post-herpetic neuralgia can be debilitating and requires aggressive treatment 5
3. Missing ocular involvement: Ocular herpes zoster can lead to serious complications and merits referral to an ophthalmologist 5
4. Failing to adjust dosage for renal impairment: This can lead to toxicity 1
5. Not recognizing treatment resistance: If lesions don't improve within 7-10 days, consider resistance and alternative therapies 4

While extending antiviral treatment from 7 to 21 days has been studied, research shows it confers only slight additional benefits and is not generally recommended as standard practice 3.