What is the recommended treatment for herpes zoster in adults?

Treatment of Herpes Zoster in Adults

For immunocompetent adults with herpes zoster, initiate oral antiviral therapy with valacyclovir 1000 mg three times daily for 7 days, ideally within 72 hours of rash onset. 1

Antiviral Therapy Selection

First-Line Treatment Options

Valacyclovir is the preferred antiviral agent due to superior pain reduction compared to acyclovir, simpler dosing (three times daily vs. five times daily), and improved bioavailability while maintaining an equivalent safety profile. 2, 3, 4

• Valacyclovir 1000 mg orally three times daily for 7 days is FDA-approved for herpes zoster treatment in immunocompetent adults 1
• Valacyclovir accelerates resolution of zoster-associated pain by approximately 13 days compared to acyclovir (median 38 days vs. 51 days) and reduces postherpetic neuralgia duration (19.3% vs. 25.7% with pain persisting at 6 months) 2
• Treatment initiated within 72 hours of rash onset provides optimal benefit, though efficacy when started beyond 72 hours has not been formally established by FDA 1

Alternative antiviral options include:

• Famciclovir 500 mg orally three times daily for 7 days demonstrates similar efficacy to valacyclovir for acute pain resolution and postherpetic neuralgia prevention 5, 4
• Acyclovir 800 mg orally five times daily for 7 days remains effective but requires more frequent dosing and provides less pain reduction than valacyclovir 2, 3, 6

Treatment Duration

Seven days of antiviral therapy is sufficient—extending treatment to 14 or 21 days provides no additional benefit for rash healing or postherpetic neuralgia prevention. 2, 6

• A 14-day valacyclovir regimen showed no significant advantage over 7 days for pain resolution or cutaneous healing 2, 4
• A 21-day acyclovir regimen conferred only slight benefits during the acute phase with no reduction in postherpetic neuralgia frequency 6

Timing of Antiviral Initiation

Initiate antiviral therapy as soon as possible, ideally within 72 hours of rash onset, though treatment may still provide benefit when started later. 1, 4

• FDA labeling states that efficacy when initiated more than 72 hours after rash onset has not been established 1
• Observational data suggest valacyclovir may retain effectiveness when started beyond 72 hours, particularly for pain reduction 4
• Do not withhold treatment if the patient presents after 72 hours—clinical judgment should guide therapy, especially in patients with ongoing vesicle formation, severe pain, or immunocompromising conditions 1

Adjunctive Corticosteroid Therapy

Corticosteroids are NOT routinely recommended as they provide minimal benefit and increase adverse events. 6

• Adding prednisolone (40 mg daily, tapered over 3 weeks) to acyclovir accelerated rash healing slightly on days 7 and 14 but did not reduce postherpetic neuralgia frequency or duration 6
• Steroid recipients reported more adverse events without meaningful long-term pain benefit 6
• Consider corticosteroids only in specific circumstances (e.g., severe acute pain, cranial nerve involvement) after weighing individual risk-benefit considerations 6

Special Populations

Immunocompromised Patients

Valacyclovir is FDA-approved for herpes zoster treatment in immunocompetent adults only—efficacy and safety in immunocompromised patients (except HIV-infected individuals with CD4+ ≥100 cells/mm³ for genital herpes suppression) have not been established. 1

• For immunocompromised patients, consider intravenous acyclovir for disseminated or severe disease 1
• The recombinant zoster vaccine (Shingrix) is recommended for immunocompromised adults aged ≥18 years to prevent future episodes 5, 7

Pediatric Patients

Valacyclovir and famciclovir are not indicated for herpes zoster treatment in patients under 18 years of age—efficacy and safety have not been established in this population. 1, 8

Pregnant Women

Valacyclovir is FDA Pregnancy Category B—use during pregnancy should be considered when benefits outweigh potential risks, particularly for severe complications like pneumonia. 5

Prevention: Vaccination Recommendations

All adults aged ≥50 years should receive the recombinant zoster vaccine (Shingrix) as a 2-dose series (0 and 2-6 months) to prevent herpes zoster and postherpetic neuralgia, regardless of prior herpes zoster history or previous Zostavax vaccination. 5, 7

• Shingrix demonstrates 97.2% efficacy in preventing herpes zoster in adults aged ≥50 years, with protection persisting for at least 8 years (>83.3% efficacy) 7
• Vaccination should be administered at least 2 months after an acute herpes zoster episode once symptoms have resolved 5, 7
• For immunocompromised adults aged ≥18 years, Shingrix is recommended with a shortened interval (1-2 months between doses) 5, 7

Common Pitfalls to Avoid

• Do not delay treatment waiting for laboratory confirmation—herpes zoster is a clinical diagnosis, and antiviral therapy should be initiated immediately upon presentation 1
• Do not use the live-attenuated zoster vaccine (Zostavax) in immunocompromised patients—only Shingrix (recombinant vaccine) is appropriate for this population 5, 7
• Do not assume prior herpes zoster provides immunity—the 10-year cumulative recurrence risk is 10.3%, and vaccination is recommended after an episode 7
• Do not extend antiviral therapy beyond 7 days routinely—longer courses provide no additional benefit and increase medication costs 2, 6