What is the recommended treatment for a patient with shingles?

Treatment of Shingles (Herpes Zoster)

For immunocompetent patients with uncomplicated shingles, initiate oral valacyclovir 1000 mg three times daily or famciclovir 500 mg three times daily for 7-10 days, continuing until all lesions have completely scabbed. 1

First-Line Oral Antiviral Therapy

Preferred agents for uncomplicated herpes zoster in immunocompetent patients include:

• Valacyclovir 1000 mg three times daily for 7-10 days – offers superior bioavailability and less frequent dosing than acyclovir, with proven efficacy in accelerating pain resolution and reducing postherpetic neuralgia duration 1, 2, 3
• Famciclovir 500 mg three times daily for 7-10 days – comparable efficacy to valacyclovir, with the unique distinction of being the only oral antiviral proven to reduce the duration of postherpetic neuralgia by approximately 3.5 months in patients ≥50 years 1, 4
• Acyclovir 800 mg five times daily for 7-10 days – remains effective but requires more frequent dosing, which may reduce adherence 1, 5

Critical Timing and Duration

• Initiate treatment within 72 hours of rash onset for optimal efficacy in reducing acute pain, accelerating lesion healing, and preventing postherpetic neuralgia 1
• Continue treatment until all lesions have completely scabbed, not just for an arbitrary 7-day period – this is the key clinical endpoint 1
• Treatment started beyond 72 hours may still provide benefit, particularly for pain reduction, but ideally should begin as early as possible 2

Intravenous Therapy Indications

Switch to IV acyclovir 10 mg/kg every 8 hours for the following scenarios:

• Disseminated herpes zoster (multi-dermatomal involvement or visceral involvement) 1
• Severely immunocompromised patients (active chemotherapy, HIV with low CD4 counts, solid organ transplant recipients) 1
• CNS complications or complicated ocular disease 1
• Failure to respond to oral therapy after 7-10 days (suspect acyclovir resistance) 1

Continue IV therapy for a minimum of 7-10 days and until clinical resolution is attained, with close monitoring of renal function and dose adjustments as needed 1

Special Population Considerations

Immunocompromised Patients

• For uncomplicated herpes zoster: oral acyclovir or valacyclovir at standard doses, but consider temporary reduction in immunosuppressive medications if clinically feasible 1
• For disseminated or invasive disease: mandatory IV acyclovir 10 mg/kg every 8 hours with temporary reduction in immunosuppression 1
• Treatment duration may need extension beyond 7-10 days, as lesions develop over longer periods (7-14 days) and heal more slowly in this population 1

Facial/Ophthalmic Involvement

• Requires particular urgency due to risk of vision-threatening complications and cranial nerve involvement 1
• Initiate oral valacyclovir 1000 mg three times daily or famciclovir 500 mg three times daily within 72 hours, continuing until all lesions have scabbed 1
• Consider ophthalmology referral for any ocular involvement 5

Renal Impairment

• Mandatory dose adjustments to prevent acute renal failure 1
• For famciclovir in herpes zoster: 500 mg every 8 hours for CrCl ≥60 mL/min, down to 250 mg every 24 hours for CrCl <20 mL/min 1
• Monitor renal function at initiation and once or twice weekly during IV acyclovir treatment 1

Adjunctive Therapies

Corticosteroids

• Prednisone may be used as adjunctive therapy in select cases of severe, widespread shingles, but benefits are modest and limited to the acute phase 1, 6
• A 21-day trial showed prednisone (40 mg daily, tapered over 3 weeks) provided greater pain reduction during days 7-14 but no reduction in postherpetic neuralgia frequency 6
• Avoid in immunocompromised patients due to increased risk of disseminated infection 1
• Contraindications: poorly controlled diabetes, history of steroid-induced psychosis, severe osteoporosis 1

Topical Therapy

• Topical antivirals are substantially less effective than systemic therapy and are not recommended 1
• Emollients may be used after lesions have crusted to prevent excessive dryness, but avoid applying any products to active vesicular lesions 1

Acyclovir-Resistant Cases

• Extremely rare in immunocompetent patients but occurs more frequently in immunocompromised patients receiving prolonged suppressive therapy 1
• For proven or suspected resistance: foscarnet 40 mg/kg IV every 8 hours until clinical resolution 1
• All acyclovir-resistant strains are also resistant to valacyclovir, and most are resistant to famciclovir 1

Infection Control

• Patients should avoid contact with susceptible individuals (those without prior chickenpox or vaccination) until all lesions have crusted 1
• Cover lesions with clothing or dressings to minimize transmission risk 1
• Healthcare workers with herpes zoster should be excluded from duty until all lesions dry and crust 1

Prevention After Recovery

• The recombinant zoster vaccine (Shingrix) is strongly recommended for all adults aged ≥50 years, regardless of prior herpes zoster episodes, providing >90% efficacy in preventing future recurrences 1
• Administer after recovery from the current episode 1
• Vaccination should ideally occur before initiating immunosuppressive therapies 1

Common Pitfalls to Avoid

• Do not discontinue antiviral therapy at exactly 7 days if lesions are still forming or have not completely scabbed – continue until all lesions have scabbed 1
• Do not use topical acyclovir as primary therapy – it is substantially less effective than systemic treatment 1
• Do not delay treatment beyond 72 hours when possible, as efficacy decreases with delayed initiation 1
• Do not use corticosteroids in immunocompromised patients due to risk of disseminated infection 1
• Do not forget renal dose adjustments for all antiviral agents to prevent acute renal failure 1