How should shingles be treated in adults, including antiviral regimen, pain management, corticosteroids, and vaccination?

Shingles Treatment in Adults

For uncomplicated herpes zoster in immunocompetent adults, initiate oral valacyclovir 1000 mg three times daily or famciclovir 500 mg three times daily within 72 hours of rash onset, continuing until all lesions have completely scabbed. 1

Antiviral Therapy

First-Line Oral Regimens

Oral antivirals are the cornerstone of shingles treatment and must be started within 72 hours of rash onset for optimal efficacy in reducing acute pain, accelerating lesion healing, and preventing postherpetic neuralgia. 1, 2

• Valacyclovir 1000 mg orally three times daily for 7–10 days is the preferred first-line agent due to superior bioavailability and less frequent dosing compared to acyclovir 1, 2
• Famciclovir 500 mg orally three times daily for 7–10 days offers comparable efficacy to valacyclovir with better bioavailability than acyclovir 1, 3
• Acyclovir 800 mg orally five times daily for 7–10 days remains effective but requires more frequent dosing, which may reduce adherence 1, 2, 4

Continue antiviral therapy until all lesions have completely scabbed—this is the key clinical endpoint, not an arbitrary 7-day duration. 1 Treatment may need to extend beyond 7–10 days if lesions remain active. 1

Intravenous Therapy Indications

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

• Disseminated herpes zoster (≥3 dermatomes, visceral involvement, or hemorrhagic lesions) 1
• Severe immunosuppression (active chemotherapy, HIV with low CD4 count, organ transplant) 1
• CNS complications (encephalitis, meningitis, Guillain-Barré syndrome) 1
• Complicated facial or ophthalmic disease 1
• Lack of clinical improvement after 7–10 days of oral therapy 1

Continue IV acyclovir for at least 7–10 days and until all lesions have completely scabbed. 1 Monitor renal function at initiation and once or twice weekly during treatment. 1

Special Populations

Immunocompromised patients with uncomplicated herpes zoster should receive oral acyclovir or valacyclovir, but maintain a low threshold for switching to IV therapy. 1, 4 Consider temporary reduction in immunosuppressive medications for disseminated or invasive disease when clinically feasible. 1

Pregnant patients with serious VZV complications (e.g., pneumonia) require intravenous acyclovir. 1

Pain Management

Acute Pain Control

For acute neuropathic pain during active shingles, initiate gabapentin as first-line therapy, titrated in divided doses up to 2400 mg per day. 1 Gabapentin improves sleep quality but causes somnolence in approximately 80% of patients. 1

• Over-the-counter analgesics (acetaminophen, ibuprofen) provide relief for mild-to-moderate acute pain 1
• Topical ice or cold packs reduce pain and swelling during the acute phase 1
• Pregabalin may be added for uncontrolled pain, particularly in postherpetic neuralgia 1

Topical anesthetics provide minimal benefit and are not recommended as primary therapy for acute zoster pain. 1

Postherpetic Neuralgia Management

For chronic neuropathic pain persisting after rash resolution:

• Gabapentin (up to 2400 mg/day in divided doses) remains first-line 1
• Pregabalin as an alternative or adjunct 1
• Tricyclic antidepressants (e.g., amitriptyline) in low doses for neuropathic pain control 2
• Capsaicin 8% patch (single application) provides analgesia lasting at least 12 weeks 1
• Narcotics may be required for severe, refractory pain 2

Corticosteroids

The addition of oral corticosteroids to antiviral therapy is NOT routinely recommended. 5 While prednisone may provide modest benefits in reducing acute pain, it does not prevent postherpetic neuralgia and carries significant risks. 5

If corticosteroids are considered in select cases of severe, widespread shingles:

• Use only as adjunctive therapy with antivirals, never alone 1
• Prednisone 40 mg daily, tapered over 3 weeks 5
• Avoid in immunocompromised patients due to increased risk of disseminated infection 1
• Avoid in patients with poorly controlled diabetes, history of steroid-induced psychosis, severe osteoporosis, or prior severe steroid toxicity 1

The evidence shows that 21 days of acyclovir or the addition of prednisolone to 7 days of acyclovir confers only slight benefits over standard 7-day acyclovir treatment, with no reduction in postherpetic neuralgia frequency. 5

Vaccination

Prevention with Shingrix

All adults aged ≥50 years should receive the recombinant zoster vaccine (Shingrix) as a 2-dose series, regardless of prior herpes zoster episodes or previous Zostavax vaccination. 6, 1, 7

• Standard schedule: Second dose given 2–6 months after the first dose 7
• Immunocompromised adults ≥18 years: Second dose given 1–2 months after the first dose 7
• Minimum interval: 4 weeks between doses 7

Shingrix demonstrates 97.2% efficacy in preventing herpes zoster in adults aged ≥50 years, with protection persisting for at least 8 years (efficacy >83.3%). 7

Vaccination After Acute Shingles

Administer Shingrix once acute symptoms have resolved, typically waiting at least 2 months after the episode. 1, 8 Having one episode of shingles does not provide reliable protection against future recurrences (10-year cumulative recurrence risk 10.3%). 1, 8

Never use live-attenuated Zostavax in immunocompromised patients—only Shingrix is appropriate. 1, 7, 8

Important Caveats

• Topical antiviral therapy is substantially less effective than systemic therapy and is not recommended 1
• Patients with shingles should avoid contact with susceptible individuals until all lesions have crusted, as lesions are contagious to those who have not had chickenpox 1
• Dose adjustments are mandatory for renal impairment to prevent acute renal failure 1
• If lesions fail to resolve within 7–10 days, suspect acyclovir resistance and obtain viral culture with susceptibility testing 1
• For confirmed acyclovir-resistant VZV, switch to foscarnet 40 mg/kg IV every 8 hours until clinical resolution 1