How should herpes zoster be managed in adults, including antiviral therapy, pain control, corticosteroid use, and vaccination recommendations for both immunocompetent and immunocompromised patients?

Management of Herpes Zoster in Adults

Antiviral Therapy

Initiate valacyclovir 1000 mg three times daily or famciclovir 500 mg every 8 hours for 7 days within 72 hours of rash onset; these agents are preferred over acyclovir due to superior bioavailability and more convenient dosing. 1

Timing and Selection

• Start antiviral therapy within 72 hours of rash onset to reduce rash duration, acute pain intensity, and risk of postherpetic neuralgia 1, 2
• Valacyclovir and famciclovir are preferred over acyclovir in older adults due to better bioavailability and less frequent dosing requirements 1
• All three agents (acyclovir, valacyclovir, famciclovir) reduce the duration of the herpetic rash and zoster-associated pain when initiated early 3, 4

Special Populations

• Immunocompromised patients with uncomplicated herpes zoster can receive oral antivirals, but monitor closely for signs of cutaneous or visceral dissemination 3
• High-dose intravenous acyclovir is the preferred therapy for immunocompromised patients with severe disease or dissemination 1
• Immunocompromised patients with severe disease may require extended therapy ranging from 6 months to 24 months 1

Common Pitfalls

• Do not delay treatment waiting for laboratory confirmation in typical presentations; diagnosis is clinical 2
• Side effects are generally mild (nausea, vomiting, abdominal pain, headache) and should not deter early treatment 4

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Pain Management

Use a stepped analgesic approach starting with acetaminophen (up to 3000-4000 mg/day divided) for mild pain, progressing to scheduled opioids for moderate-severe pain, and add gabapentin 100-300 mg at bedtime (titrating to 300-600 mg three times daily) from the acute phase to prevent postherpetic neuralgia. 1

Acute Pain Control

• Mild to moderate pain: Acetaminophen up to 3000-4000 mg/day in divided doses is preferred due to lower adverse effect profile in older adults 1
• NSAIDs should be used with extreme caution in older adults due to risks of gastrointestinal toxicity, renal impairment, hypertension, and heart failure; if used, monitor renal function, blood pressure, and drug interactions routinely 1
• Moderate to severe pain: Start opioids at low doses with gradual titration; use scheduled dosing for frequent or continuous pain 1
• Anticipate and manage opioid-related adverse effects including sedation, cognitive impairment, falls, and constipation—particularly critical in older adults 1

Adjuvant Therapy for Preventing Postherpetic Neuralgia

• Gabapentin should be considered as initial therapy alongside conventional analgesics, starting with 100-300 mg at bedtime and gradually titrating up to 300-600 mg three times daily as tolerated 1
• Nortriptyline is preferred over amitriptyline in older adults due to lower anticholinergic profile; start at 10-25 mg at bedtime and slowly titrate 1

Topical Therapies

• Lidocaine 5% patch is highly effective for localized neuropathic pain; apply up to 3 patches for 12 hours daily over the affected area 1
• The patch delivers lidocaine gradually over hours with no systemic absorption or toxicity, making it exceptionally safe for elderly patients 1
• Lidocaine 5% patch is significantly more effective than lidocaine gel or cream for zoster-related pain 1
• Capsaicin topical therapy may benefit a small proportion of patients but is often poorly tolerated 1

Medications to Avoid in Older Adults

• Muscle relaxants (cyclobenzaprine, carisoprodol) due to significant anticholinergic effects and increased fall risk 1
• Benzodiazepines due to sedation, cognitive impairment, and increased fall risk 1

Postherpetic Neuralgia Treatment

• If postherpetic neuralgia develops, consider gabapentin, pregabalin, opioids, tricyclic antidepressants, lidocaine patch 5%, or capsaicin as palliative treatments 5
• Most patients require a combination of treatment modalities for adequate pain relief due to the complexity of postherpetic neuralgia 4
• For treatment-refractory postherpetic neuralgia, consult a pain-management specialist and consider nonpharmacologic approaches 5

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Corticosteroid Use

Do not routinely add corticosteroids to antiviral therapy; while they may provide modest short-term pain reduction, they are associated with increased risk of serious adverse effects in older adults and do not prevent postherpetic neuralgia. 6, 5

• The addition of oral corticosteroids to antiviral medication may provide modest benefits in reducing short-term zoster pain but does not reduce the incidence of postherpetic neuralgia 6
• Corticosteroids are associated with an increased risk of serious adverse effects, especially among older adults 5
• If corticosteroids are used for any reason (e.g., ocular involvement), they must always be used in conjunction with systemic antiviral therapy, never alone 7

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Vaccination Recommendations

Immunocompetent Adults

All immunocompetent adults ≥50 years should receive the recombinant zoster vaccine (Shingrix) as a 2-dose series with the second dose given 2-6 months after the first, regardless of prior herpes zoster history or previous Zostavax vaccination. 8, 1, 9

Vaccine Selection and Efficacy

• Shingrix (RZV) is the only herpes zoster vaccine currently available in the United States; Zostavax was discontinued in November 2020 8
• Shingrix demonstrates 97.2% efficacy in preventing herpes zoster in adults ≥50 years 1, 9
• Protection persists for at least 8 years with efficacy remaining above 83.3%, with minimal waning 1, 9
• Shingrix offers significantly higher efficacy compared to the older Zostavax (97% vs 70%), and Zostavax efficacy declined dramatically with age (70% in ages 50-59 vs 18% in those ≥80 years) 9

Dosing Schedule

• Administer the second dose 2-6 months after the first dose 1, 9
• The minimum interval between doses is 4 weeks; if administered earlier, the dose should be repeated 1, 9
• There is no maximum interval after the first dose; if the second dose is delayed, simply administer it as soon as possible without restarting the series 1

Vaccination After Prior Herpes Zoster

• Vaccinate patients regardless of prior herpes zoster history because a single episode does not provide reliable protection against recurrence 1, 9
• The 10-year cumulative recurrence risk is 10.3% 1, 9
• Administer vaccination ≥2 months after resolution of acute symptoms, though no absolute minimum waiting period is mandated 1, 9

Vaccination After Prior Zostavax

• Adults who previously received Zostavax should receive the full 2-dose Shingrix series because Zostavax efficacy declines to only 14.1% by year 10 1, 9
• Administer Shingrix at least 2 months after Zostavax 1, 9

Safety Profile

• Common side effects include injection-site reactions (pain, redness, swelling) in 9.5% (grade 3) compared to 0.4% with placebo 9
• Systemic symptoms occur in 11.4% of vaccine recipients versus 2.4% in placebo recipients 9
• Most adverse reactions are transient, mild-to-moderate, and resolve within approximately 4 days 1, 9
• No serious safety concerns have been identified in large clinical trials 9

Immunocompromised Adults

Immunocompromised adults ≥18 years should receive the recombinant zoster vaccine (Shingrix) with a shortened schedule of 1-2 months between doses; the live-attenuated Zostavax is absolutely contraindicated in this population. 8, 1, 9

Eligible Populations

• Adults with hematologic malignancies (e.g., multiple myeloma) receiving or who have completed cancer therapy 1
• Recipients of autologous hematopoietic stem cell transplantation (administer first dose 50-70 days post-transplant) 1
• Solid organ transplant recipients (4-18 months post-transplant) 1
• Adults with solid tumors undergoing chemotherapy 1
• Patients with autoimmune inflammatory rheumatic diseases on immunosuppressive therapy 9
• Patients on JAK inhibitors (e.g., tofacitinib) 1

Dosing Schedule

• Administer the second dose 1-2 months after the first dose (shorter than the standard 2-6 month interval) to achieve earlier protection 1, 9
• The minimum interval of 4 weeks between doses remains mandatory 1

Timing Considerations

• Ideally complete the full 2-dose series before initiating immunosuppressive therapy to maximize immune response 1, 9
• If urgent immunosuppressive therapy is required, administer at least the first dose before starting therapy, with the second dose completed after therapy has been started (though immune response may be somewhat reduced) 1
• Consider administering Shingrix between chemotherapy cycles (>7 days after last treatment) when feasible to optimize vaccine response 1
• When possible, hold immunosuppressive medication for an appropriate period before vaccination and for 4 weeks after vaccination to ensure robust immune response 1

Safety and Contraindications

• Shingrix is a non-live recombinant vaccine, making it safe for immunocompromised patients 8, 1, 9
• Never use live-attenuated Zostavax in immunocompromised patients due to risk of disseminated VZV infection 1, 9
• Concomitant low-dose glucocorticoids (prednisone equivalent <10 mg/day) do not adversely impact vaccine response 1

Special Considerations

• Shingrix can be safely administered to patients on multiple medications with minimal drug interactions due to negligible systemic absorption 1
• Particularly valuable for patients with renal impairment who require dose adjustments of systemic medications 1
• Vaccination is recommended even in patients with a history of previous herpes zoster 8, 1

Patients with History of Herpetic Keratitis

Use Shingrix exclusively (not Zostavax) in patients with a history of herpetic keratitis; administer the first dose when keratitis has been completely quiescent for at least 2-3 months, with the second dose 2-6 months later. 7

• Shingrix is preferred over Zostavax due to higher efficacy (96% vs 70%) and lower theoretical risk of viral reactivation 7
• Shingrix contains only a viral protein fragment (glycoprotein E) with adjuvant, reducing the risk of viral reactivation compared to the live-attenuated Zostavax 7
• If reactivation of herpetic keratitis occurs after vaccination, treat with standard oral antivirals and topical corticosteroids (always used in conjunction with systemic antiviral therapy, never alone) 7
• The benefits of vaccination generally outweigh the rare risk of reactivation, especially with Shingrix, which has 97.2% efficacy in preventing herpes zoster and drastically reduces the risk of a new ocular episode 7