Treatment of Herpes Zoster (Shingles) in Adults
First-Line Antiviral Therapy
Initiate oral antiviral therapy immediately upon diagnosis, ideally within 72 hours of rash onset, using valacyclovir 1000 mg three times daily for 7 days, acyclovir 800 mg five times daily for 7 days, or famciclovir 500 mg three times daily for 7 days. 1, 2, 3
Antiviral Selection and Dosing
Valacyclovir is preferred due to superior convenience (three times daily vs. five times daily for acyclovir) and demonstrated faster resolution of zoster-associated pain and postherpetic neuralgia compared to acyclovir. 2, 3
Valacyclovir 1.5 g twice daily for 7 days is an alternative regimen that enhances compliance while maintaining equivalent efficacy to the standard three-times-daily dosing. 4
All three oral antivirals (valacyclovir, acyclovir, famciclovir) significantly reduce the duration and intensity of acute pain, accelerate rash healing, and are similarly effective when compared head-to-head. 1, 2, 5
Starting treatment beyond 72 hours may still provide benefit, particularly for pain reduction, though earlier initiation is optimal. 2, 5
Special Considerations for Immunocompromised Patients
Oral antivirals are appropriate for mild, uncomplicated herpes zoster in immunocompromised patients. 1
Switch to high-dose intravenous acyclovir immediately if any signs of cutaneous or visceral dissemination develop, as oral agents are inadequate for severe disease in this population. 1
Pain Management
Acute Phase Pain Control
Combine antiviral therapy with adjunctive analgesics including opioids for moderate-to-severe pain, as antivirals alone address viral replication but not immediate pain relief. 3, 5
Consider adding oral corticosteroids (e.g., prednisone) to the antiviral regimen for modest additional benefit in reducing acute pain, though this does not prevent postherpetic neuralgia. 3
Tricyclic antidepressants (e.g., amitriptyline, nortriptyline) in low doses can be initiated during the acute phase to address neuropathic pain components. 3, 5
Postherpetic Neuralgia Management
If pain persists beyond 30 days after rash healing, treat postherpetic neuralgia with first-line agents: tricyclic antidepressants, gabapentin, pregabalin, or long-acting opioids/tramadol. 5
Second-line topical therapies include capsaicin cream or lidocaine patches for localized pain that is refractory to systemic agents. 3, 5
Nerve blocks may be considered in selected patients with severe, refractory pain. 3
Vaccination Recommendations
For Patients Who Have Had Shingles
Administer the recombinant zoster vaccine (Shingrix) once acute symptoms have resolved, waiting at least 2 months after the episode, as having shingles once does not provide reliable protection against recurrence (10.3% cumulative risk at 10 years). 6, 7
Give the two-dose Shingrix series with the second dose administered 2–6 months after the first dose (minimum interval 4 weeks). 6, 7
For immunocompromised adults aged ≥18 years, use a shortened schedule with the second dose at 1–2 months after the first dose. 6, 7
For Patients Without Prior Shingles
All adults aged 50 years and older should receive the two-dose Shingrix series regardless of prior herpes zoster history or previous Zostavax vaccination. 8, 6
Shingrix demonstrates 97.2% efficacy in preventing herpes zoster in adults aged 50 and older, with protection sustained for at least 8 years. 6
For patients who previously received Zostavax, administer Shingrix at least 2 months after the last Zostavax dose, as the older live vaccine provides inadequate long-term protection (efficacy drops to 14.1% by year 10). 6
Important Vaccination Caveats
Never use live-attenuated Zostavax in immunocompromised patients (those on biologics, JAK inhibitors, chemotherapy, high-dose corticosteroids, or with HIV)—only Shingrix is safe for this population. 6, 7
Shingrix can be administered to patients on low-dose glucocorticoids (<10 mg/day prednisone equivalent) without adversely impacting vaccine response. 6
Common side effects include injection-site reactions (9.5% grade 3) and systemic symptoms (11.4%), but these are transient and no serious safety concerns have been identified. 6
Critical Clinical Pitfalls to Avoid
Do not delay antiviral therapy waiting for laboratory confirmation—herpes zoster is a clinical diagnosis based on the characteristic unilateral dermatomal vesicular rash. 5
Do not withhold antivirals beyond 72 hours if the patient presents late, as some benefit may still be achieved, particularly for pain reduction. 2
Do not assume antiviral therapy alone prevents postherpetic neuralgia—evidence is conflicting, and multimodal pain management is essential. 5
Monitor immunocompromised patients closely for signs of dissemination requiring escalation to intravenous therapy. 1
Do not skip vaccination after a shingles episode—natural immunity from one episode does not reliably prevent recurrence. 6, 7