What is the treatment for shingles?

Treatment of Shingles (Herpes Zoster)

For immunocompetent adults with uncomplicated shingles, initiate oral antiviral therapy with valacyclovir 1 gram three times daily, famciclovir 500 mg three times daily, or acyclovir 800 mg five times daily for 7-10 days, ideally within 72 hours of rash onset, and continue treatment until all lesions have completely scabbed. 1, 2, 3, 4

First-Line Oral Antiviral Options

The three FDA-approved oral antivirals are equally effective for treating shingles, but differ in dosing convenience:

• Valacyclovir 1 gram three times daily - preferred due to better bioavailability and convenient dosing 1, 5, 4
• Famciclovir 500 mg every 8 hours - equally effective with three-times-daily dosing 1, 3, 6, 4
• Acyclovir 800 mg five times daily - effective but requires more frequent dosing, which may reduce compliance 1, 2, 6, 4

Treatment should be initiated within 72 hours of rash onset for maximum benefit, though starting within 48 hours is optimal 1, 4. The standard duration is 7-10 days, but treatment must continue until all lesions have completely scabbed, not just for an arbitrary 7-day period 1, 2. This is the key clinical endpoint that determines when to stop therapy 1.

Intravenous Therapy for Severe or Complicated Cases

Intravenous acyclovir is mandatory for:

• Disseminated herpes zoster (multi-dermatomal or visceral involvement) 1
• Immunocompromised patients with severe disease 1, 2
• Ophthalmic zoster with suspected CNS involvement 1
• Patients unable to tolerate oral medications 1

The recommended IV dose is acyclovir 10 mg/kg every 8 hours for severely immunocompromised hosts 1. In immunocompromised patients with disseminated disease, consider temporarily reducing immunosuppressive medications 1, 2.

Special Populations

Immunocompromised Patients

These patients require more aggressive management with IV acyclovir 5 mg/kg every 8 hours (or 10 mg/kg for severely immunocompromised hosts) due to high risk of dissemination and complications 1, 2. This includes patients on chemotherapy, those with HIV, transplant recipients, and patients on immunosuppressive therapies 1. Treatment duration should be at least 7-10 days and continue until clinical resolution 1.

HIV-Infected Patients

For HIV-positive patients with herpes zoster, higher oral doses may be needed (up to 800 mg 5-6 times daily), and consideration should be given to long-term acyclovir prophylaxis (400 mg 2-3 times daily) 1. If lesions persist despite treatment, monitor for acyclovir resistance 1.

Facial/Ophthalmic Zoster

Facial herpes zoster requires particular urgency due to risk of ophthalmic and cranial nerve complications 1. Initiate oral valacyclovir 1 gram three times daily or famciclovir 500 mg three times daily immediately, with consideration for IV therapy if there is suspected CNS involvement or severe ophthalmic disease 1.

Critical Treatment Pitfalls to Avoid

• Never use topical acyclovir - it is substantially less effective than oral therapy and is not recommended 1, 2
• Do not underdose - using inadequate doses (such as 400 mg TDS, which is only appropriate for genital herpes) will lead to treatment failure 1
• Do not stop at 7 days if lesions remain active - continue until all lesions have scabbed 1, 2
• Do not delay treatment - efficacy decreases significantly after 72 hours from rash onset 1, 4
• Monitor renal function closely during IV acyclovir therapy and adjust doses for renal impairment 1

Adjunctive Corticosteroid Therapy

Corticosteroids (prednisone) may be considered as adjunctive therapy in select cases of severe, widespread shingles, but should generally be avoided in immunocompromised patients due to increased risk of disseminated infection 1. A randomized trial found that adding prednisolone to acyclovir provided only slight benefits in acute pain reduction during the first 14 days, with no reduction in postherpetic neuralgia 7. Corticosteroids carry significant risks, particularly in elderly patients, and are contraindicated in patients with poorly controlled diabetes, history of steroid-induced psychosis, or severe osteoporosis 1.

Prevention and Post-Exposure Prophylaxis

The recombinant zoster vaccine (Shingrix) is recommended for all adults aged 50 years and older, regardless of prior herpes zoster episodes 1, 4. Vaccination should ideally occur before initiating immunosuppressive therapies 1.

For varicella-susceptible patients exposed to active varicella zoster infection, administer varicella zoster immunoglobulin (VZIG) within 96 hours of exposure 8, 1. If immunoglobulin is unavailable or more than 96 hours have passed, give a 7-day course of oral acyclovir beginning 7-10 days after exposure 1.

Acyclovir-Resistant Cases

If lesions do not begin to resolve within 7-10 days of therapy, suspect acyclovir resistance 1. For proven or suspected acyclovir-resistant herpes zoster, use foscarnet 40 mg/kg IV every 8 hours 1.

Infection Control

Patients with shingles should avoid contact with susceptible individuals (those who have not had chickenpox or vaccination) until all lesions have crusted, as lesions are contagious 1, 9.