What is the treatment for shingles?

Treatment for Shingles (Herpes Zoster)

Antiviral therapy with acyclovir 800 mg orally 5 times daily for 7-10 days is the first-line treatment for herpes zoster, with valacyclovir and famciclovir offering similar efficacy but with more convenient dosing schedules. 1

First-Line Antiviral Options

The CDC recommends the following antiviral medications for treating shingles:

1. Acyclovir: 800 mg orally 5 times daily for 7-10 days

   • Most extensive clinical experience
   • For severe cases: IV acyclovir 10 mg/kg every 8 hours

2. Alternative oral options (more convenient dosing):

   • Valacyclovir: 1000 mg three times daily for 7 days
   • Famciclovir: 500 mg three times daily for 7 days 1

Important: Treatment should be initiated within 72 hours of rash onset for maximum effectiveness. Early treatment can sometimes abort the episode entirely. 1

Dosage Adjustments for Renal Impairment

For acyclovir, adjust dosage based on creatinine clearance:

• CrCl >25 mL/min: 800 mg every 4 hours, 5 times daily
• CrCl 10-25 mL/min: 800 mg every 8 hours
• CrCl 0-10 mL/min: 800 mg every 12 hours 1

For famciclovir, dosage adjustment is also required for patients with renal impairment. 2

Pain Management

Pain management should be addressed alongside antiviral therapy:

• Mild pain: Acetaminophen or NSAIDs
• Moderate to severe pain: Consider:
  • Gabapentin or pregabalin
  • Tricyclic antidepressants
  • Lidocaine patches for localized pain 1

For severe pain, follow the WHO pain management ladder for systematic analgesic therapy. 1

Special Populations

Immunocompromised Patients

• May require longer treatment duration and closer monitoring
• For acyclovir-resistant infections: foscarnet 40 mg/kg IV 3 times daily 1

Pregnant Women

• Acyclovir is the first-line treatment due to its established safety profile
• 800 mg orally 5 times daily until all lesions have scabbed or completely healed 1

Patients with Ophthalmic Involvement

• Start valacyclovir 1000 mg three times daily for 7 days or famciclovir 500 mg three times daily for 7 days
• Urgent ophthalmology referral is essential due to risk of complications including keratitis, corneal scarring, uveitis, and secondary glaucoma 1

Clinical Evidence and Efficacy

Famciclovir has been shown to significantly reduce viral shedding and accelerate lesion resolution compared to placebo. Most importantly, it reduces the duration of postherpetic neuralgia (PHN) by approximately 3.5 months in patients 50 years or older. 3

A comparative study showed that famciclovir 750 mg once daily, 500 mg twice daily, or 250 mg three times daily had comparable efficacy to acyclovir 800 mg five times daily with respect to cutaneous healing of herpes zoster. 4

Another study suggested that famciclovir may provide superior acute pain relief compared to valacyclovir in the early treatment phase. 5

Common Pitfalls and Caveats

1. Delayed treatment: Initiating antiviral therapy beyond 72 hours of rash onset significantly reduces effectiveness. Treat as early as possible.

2. Inadequate pain management: Pain control is essential for quality of life during acute herpes zoster and for preventing chronic postherpetic neuralgia.

3. Missing ophthalmic involvement: Always check for ocular involvement. If present, urgent ophthalmology referral is necessary.

4. Inappropriate use of topical corticosteroids: Avoid prescribing topical corticosteroids without concurrent antiviral therapy as this can potentiate HSV infections. 1

5. Failure to adjust dosage for renal impairment: This can lead to acute renal failure in patients with underlying renal disease. 2

Follow-up

Schedule follow-up within 7 days to:

• Assess treatment response
• Monitor for complete resolution of lesions
• Evaluate for signs of dissemination or complications
• Ensure ophthalmology evaluation has occurred if indicated 1