Treatment of Herpes Zoster Virus (Shingles)
Acyclovir 800 mg orally five times daily for 7-10 days is the first-line treatment for herpes zoster virus infections. 1
First-Line Antiviral Options
Oral Antiviral Medications
- Acyclovir: 800 mg orally 5 times daily for 7-10 days 2, 1
- Valacyclovir: 1000 mg orally 3 times daily for 7 days 3, 4
- Famciclovir: 500 mg orally 3 times daily for 7 days 3, 5
Treatment Selection Considerations
- Acyclovir is FDA-approved specifically for herpes zoster and has the most extensive clinical experience 1
- Valacyclovir offers better bioavailability and less frequent dosing compared to acyclovir, which may improve adherence 4
- Famciclovir has similar efficacy to valacyclovir with the same dosing frequency 5
Special Populations
Immunocompromised Patients
- Consider higher doses and longer duration (10-14 days)
- For severe cases: Intravenous acyclovir 10 mg/kg every 8 hours 2
- For acyclovir-resistant infections: Foscarnet 40 mg/kg IV 3 times daily 2
Pediatric Dosing
- For children <45 kg: Acyclovir 20 mg/kg body weight (maximum 800 mg/dose) orally 4 times daily for 7-10 days 2, 3
- Famciclovir is not established for use in pediatric patients 6
Elderly Patients
- No dosage adjustment needed based on age alone
- Adjust dose based on renal function 6
Renal Impairment
Acyclovir dosage adjustment based on creatinine clearance:
- CrCl >25 mL/min: 800 mg 5 times daily
- CrCl 10-25 mL/min: 800 mg every 8 hours
- CrCl <10 mL/min: 800 mg every 12 hours 3
Pain Management
- Mild pain: Acetaminophen or NSAIDs
- Moderate to severe pain: Consider gabapentin, pregabalin, or tricyclic antidepressants
- For localized pain: Lidocaine patches may be applied to affected areas 3
Treatment Timing
- Antiviral therapy should be initiated within 72 hours of rash onset for maximum effectiveness 7, 4
- Some benefit may still be obtained when starting treatment later than 72 hours, especially in patients with continued new vesicle formation or immunocompromised status 3
Follow-Up and Monitoring
- Schedule follow-up within 7 days to assess treatment response 3
- Monitor for complete resolution of lesions
- Evaluate for complications such as postherpetic neuralgia
- Consider extended pain management for patients who develop postherpetic neuralgia 3
Common Pitfalls to Avoid
- Delayed treatment: Starting antivirals after 72 hours significantly reduces efficacy
- Inadequate dosing: Using lower doses than recommended reduces effectiveness
- Insufficient duration: Stopping treatment before 7 days may lead to incomplete resolution
- Overlooking ocular involvement: Herpes zoster ophthalmicus requires urgent ophthalmologic consultation
- Neglecting pain management: Pain control is an essential component of treatment
Valacyclovir and famciclovir have better bioavailability and less frequent dosing requirements compared to acyclovir, which may improve patient adherence 8, 4. However, acyclovir remains the most established treatment with the longest history of use for herpes zoster infections 1.