Treatment of Shingles in Adults Over 50
For an adult over 50 diagnosed with shingles, initiate oral antiviral therapy immediately—preferably within 72 hours of rash onset—with valacyclovir 1000 mg three times daily for 7 days, which is the preferred first-line treatment based on superior dosing convenience and comparable efficacy to acyclovir. 1
Antiviral Treatment Options
The three FDA-approved oral antivirals for herpes zoster are equally effective when started early:
- Valacyclovir 1000 mg three times daily for 7 days (preferred for convenience) 1
- Famciclovir 500 mg three times daily for 7 days 2
- Acyclovir 800 mg five times daily for 7-10 days (requires more frequent dosing) 3, 4
All three agents significantly reduce acute pain intensity, accelerate healing of the vesicular rash, and shorten the duration of viral shedding when initiated within 72 hours of rash appearance. 4, 5
Critical Timing Considerations
Treatment must be initiated within 72 hours of rash onset to maximize benefit. 1 Clinical trials demonstrating efficacy enrolled patients treated within this window. 1, 5 Even earlier treatment (within 24-48 hours) may provide additional benefit for preventing complications. 5, 6
Patients typically experience burning pain 24-72 hours before the characteristic unilateral dermatomal vesicular rash appears. 7 Do not wait for laboratory confirmation—the diagnosis is clinical based on the characteristic dermatomal distribution and vesicular appearance. 8
Postherpetic Neuralgia Prevention
The evidence regarding antiviral therapy preventing postherpetic neuralgia (PHN) remains conflicting. 4, 5 Some studies show reduced PHN duration and severity with early antiviral treatment, while others show no convincing benefit. 4, 5
In patients over 50 years treated with valacyclovir, the median duration of post-healing pain was 40 days with 7-day treatment and 43 days with 14-day treatment, compared to 59 days with acyclovir. 1 However, these differences were not consistently significant across all studies. 5
The most effective strategy to prevent PHN is vaccination with recombinant zoster vaccine (Shingrix) before shingles develops, not antiviral treatment after infection occurs. 9, 10, 11
Special Populations Requiring Aggressive Treatment
Immunocompromised patients require intravenous acyclovir 10 mg/kg every 8 hours rather than oral therapy due to higher risk of dissemination, visceral involvement, and prolonged disease course. 3, 5 This includes patients on immunosuppressive therapy, those with HIV/AIDS, cancer patients, and transplant recipients. 9
Herpes zoster ophthalmicus (involvement of the ophthalmic division of the trigeminal nerve) requires urgent ophthalmologic consultation in addition to antiviral therapy, as approximately 50% develop ocular complications including keratitis, uveitis, and potential vision loss. 11, 8
Adjunctive Pain Management
Antiviral therapy alone does not adequately address acute pain. Concurrent analgesic therapy is essential:
- Acute neuritis: Use standard analgesics including NSAIDs and opioids as needed for severe pain 8
- If PHN develops: Consider gabapentin, pregabalin, tricyclic antidepressants (amitriptyline), or combination therapy with amitriptyline and fluphenazine 8, 6
Some evidence suggests initiating gabapentin concomitantly with antivirals at rash onset may reduce complication severity, though data on PHN prevention specifically are lacking. 6
Common Pitfalls to Avoid
Do not delay treatment waiting for "classic" presentation—atypical presentations occur, especially in immunocompromised patients who may have multiple dermatomes involved or hemorrhagic lesions. 8
Do not use topical acyclovir as monotherapy—it provides minimal benefit compared to systemic therapy. 3
Ensure adequate hydration and monitor renal function when using high-dose antivirals, particularly in elderly patients, as dosage adjustment is required for renal impairment. 2, 3
Patients remain contagious from 1-2 days before rash onset until all lesions are fully crusted (typically 7-10 days), so counsel on infection control measures including avoiding contact with pregnant women, immunocompromised individuals, and those without varicella immunity. 7