What is the treatment for herpes zoster (shingles)?

Treatment of Herpes Zoster (Shingles)

Initiate oral antiviral therapy with valacyclovir 1000 mg three times daily, famciclovir 500 mg three times daily, or acyclovir 800 mg five times daily for 7-10 days, starting within 72 hours of rash onset, and continue treatment until all lesions have completely scabbed. 1, 2, 3, 4

First-Line Oral Antiviral Therapy

Standard Dosing Regimens

• Valacyclovir 1000 mg three times daily for 7 days is FDA-approved for herpes zoster treatment in immunocompetent adults 2
• Famciclovir 500 mg every 8 hours for 7 days is equally effective with better bioavailability than acyclovir 4, 5
• Acyclovir 800 mg five times daily for 7-10 days remains an effective option, though requires more frequent dosing 6, 3

Critical Timing Window

• Treatment must be initiated within 72 hours of rash onset for optimal efficacy in reducing acute pain, accelerating lesion healing, and preventing postherpetic neuralgia 6, 1, 7
• Antiviral therapy is most effective when started within 48 hours, but the 72-hour window represents the maximum timeframe for meaningful benefit 1
• Treatment initiated after 72 hours has not been established as effective by FDA standards 2

Treatment Duration Endpoint

• Continue antiviral therapy until all lesions have completely scabbed, not just for an arbitrary 7-day period 1
• This is the key clinical endpoint that should guide treatment duration, particularly in immunocompromised patients who may require extended therapy 1

Escalation to Intravenous Therapy

Indications for IV Acyclovir

Switch to intravenous acyclovir 10 mg/kg every 8 hours for: 1

• Disseminated herpes zoster (multi-dermatomal or visceral involvement)
• Severely immunocompromised patients (including those on chemotherapy)
• Central nervous system complications
• Complicated ocular disease
• Patients who cannot tolerate or absorb oral medications

IV Treatment Duration

• Continue IV acyclovir for a minimum of 7-10 days and until clinical resolution is attained 1
• Monitor renal function closely with dose adjustments as needed for renal impairment 1
• Consider temporary reduction in immunosuppressive medications in disseminated cases 1

Special Population Considerations

Immunocompromised Patients

• High-dose IV acyclovir remains the treatment of choice for severely compromised hosts with VZV infections 1
• Immunocompromised patients may develop new lesions for 7-14 days (versus 4-6 days in immunocompetent patients) and require extended treatment duration 1
• Without adequate antiviral therapy, some immunocompromised patients develop chronic ulcerations with persistent viral replication 1

Facial/Ophthalmic Involvement

• Facial 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 within 72 hours 1
• Consider IV acyclovir for suspected CNS involvement or severe ophthalmic disease 1

Renal Impairment

• Dose adjustments are mandatory to prevent acute renal failure 1
• For famciclovir with CrCl ≥60 mL/min: 500 mg every 8 hours; adjust downward for lower clearance rates 1, 4
• Monitor renal function closely during IV acyclovir therapy 1

Adjunctive Pain Management

Acute Zoster Pain

• Analgesics should be used for control of acute zoster pain alongside antiviral therapy 8
• Topical anesthetics provide minimal benefit and are not recommended as primary therapy 1

Postherpetic Neuralgia Prevention

• Valacyclovir and famciclovir are superior to acyclovir for reducing postherpetic neuralgia risk due to better bioavailability 1
• Famciclovir reduces the median duration of postherpetic neuralgia by approximately 2 months compared to placebo 5
• Both 500 mg and 750 mg famciclovir three times daily demonstrate approximately twofold faster resolution of postherpetic neuralgia 5

Critical Pitfalls to Avoid

Common Treatment Errors

• Never use topical antiviral therapy alone—it is substantially less effective than systemic therapy 1
• Do not stop treatment at 7 days if lesions have not completely scabbed; continue until full crusting occurs 1
• Do not delay treatment waiting for laboratory confirmation in typical presentations 1
• Avoid using acyclovir 400 mg three times daily—this dose is only appropriate for genital herpes or HSV suppression, not shingles 1

Monitoring Requirements

• Assess for complete healing of lesions at follow-up 1
• Monitor for signs of dissemination in immunocompromised patients (multi-dermatomal involvement, visceral symptoms) 9
• Watch for acyclovir resistance if lesions persist despite adequate treatment 1

Infection Control

• Patients should avoid contact with susceptible individuals until all lesions have crusted, as lesions are contagious to those who have not had chickenpox 1

Prevention Considerations

• The recombinant zoster vaccine (Shingrix) is recommended for all adults aged ≥50 years, regardless of prior herpes zoster episodes 1
• Vaccination should ideally occur before initiating immunosuppressive therapies 1
• Prior vaccination does not eliminate the need for antiviral treatment if herpes zoster develops 1