What is the treatment for herpes zoster?

Treatment of Herpes Zoster

The standard treatment for herpes zoster is oral antiviral therapy with acyclovir, valacyclovir, or famciclovir, which should be initiated within 72 hours of rash onset to reduce severity, duration, and risk of postherpetic neuralgia. 1

First-Line Antiviral Therapy

Recommended Regimens:

• Acyclovir: 800 mg orally five times daily for 7-10 days
• Valacyclovir: 1000 mg orally three times daily for 7 days
• Famciclovir: 500 mg orally three times daily for 7 days 1

Valacyclovir and famciclovir are preferred over acyclovir due to better bioavailability and less frequent dosing requirements, improving patient adherence 1, 2.

Treatment Timing

Treatment efficacy is maximized when initiated within 72 hours of rash onset 2. Starting treatment at the first sign of prodrome (pain before rash appears) can significantly improve outcomes 1. Even after 72 hours, antiviral therapy should be considered in the following situations:

• New or ongoing vesicle formation
• Immunocompromised patients
• Severe pain
• Involvement of the face or other critical areas 3

Special Populations

Immunocompromised Patients:

• Higher risk for disseminated disease and complications
• Require higher doses or longer duration of treatment
• Intravenous acyclovir may be necessary for severe cases 3
• Monitoring for potential antiviral resistance is important 1

Pregnant Patients:

• Acyclovir 400 mg orally three times daily for 5-7 days is preferred due to established safety profile 1
• IV acyclovir is indicated for life-threatening infections 1

Management of Pain

Acute Pain:

• Analgesics ranging from acetaminophen to opioids based on pain severity
• Good skin care to prevent secondary bacterial infection 3

Prevention of Postherpetic Neuralgia (PHN):

• Early antiviral therapy (especially valacyclovir or famciclovir) has been shown to reduce the risk of PHN 2, 4
• Famciclovir has demonstrated approximately twofold faster resolution of PHN compared to placebo 4

Treatment of Established PHN:

• Tricyclic antidepressants (e.g., amitriptyline)
• Anticonvulsants (e.g., gabapentin, pregabalin)
• Topical agents (lidocaine patches, capsaicin cream)
• Opioid analgesics for severe, refractory pain 5, 6, 7

Complications Requiring Special Attention

• Ophthalmic zoster: Involvement of the ophthalmic division of the trigeminal nerve requires urgent ophthalmology consultation 5
• Disseminated zoster: More common in immunocompromised patients, may require intravenous therapy 3
• Resistant infections: Consider foscarnet (40 mg/kg three times daily) for acyclovir-resistant cases 1

Prevention

• Zoster vaccine is recommended for adults ≥60 years to reduce the incidence of herpes zoster and PHN 2
• Immunocompromised patients at high risk should consider prophylactic antiviral therapy 3

Treatment Monitoring

• Clinical improvement should be seen within 7-10 days of treatment initiation
• If lesions do not begin to resolve within this timeframe, consider treatment failure or resistance 1
• Secondary bacterial infection may require additional antimicrobial therapy

Common Pitfalls to Avoid

1. Delaying antiviral therapy beyond 72 hours
2. Inadequate pain management during acute phase
3. Failing to recognize ophthalmic involvement requiring specialist care
4. Underestimating the need for more aggressive therapy in immunocompromised patients
5. Not considering antiviral resistance in patients with poor response to standard therapy

Early, appropriate antiviral therapy remains the cornerstone of herpes zoster management, with significant implications for both acute symptom control and prevention of long-term complications like PHN.