Treatment of Shingles (Herpes Zoster)
For uncomplicated shingles, start oral valacyclovir 1000 mg three times daily for 7 days, initiating treatment within 72 hours of rash onset for optimal efficacy in reducing acute pain, accelerating lesion healing, and preventing postherpetic neuralgia. 1, 2
First-Line Antiviral Therapy
Standard Oral Treatment Options
Valacyclovir 1000 mg three times daily for 7 days is the preferred first-line agent due to superior bioavailability (3-5 fold higher than acyclovir), less frequent dosing that improves adherence, and proven superiority in accelerating pain resolution compared to acyclovir 1, 2, 3, 4
Acyclovir 800 mg five times daily for 7-10 days remains an effective alternative, though it requires more frequent dosing 1, 2
Famciclovir 500 mg three times daily for 7 days offers comparable efficacy to valacyclovir and is the only oral antiviral proven to reduce the duration of postherpetic neuralgia by 3.5 months in patients ≥50 years old 1, 5
Critical Timing Considerations
Initiate treatment within 72 hours of rash onset for maximum benefit in reducing acute pain and preventing postherpetic neuralgia 1, 2, 6
Treatment within 48 hours is most effective, but benefit extends beyond 72 hours in observational studies 1, 3
Continue treatment until all lesions have completely scabbed, not just for an arbitrary 7-day period—this is the key clinical endpoint 1
Escalation to Intravenous Therapy
Indications for IV Acyclovir
Disseminated or invasive herpes zoster (multi-dermatomal involvement, visceral involvement) requires IV acyclovir 10 mg/kg every 8 hours 1
Immunocompromised patients (HIV, cancer, chemotherapy, chronic immunosuppression) should receive IV acyclovir 10 mg/kg every 8 hours due to high risk of dissemination 1
Complicated facial zoster with suspected CNS involvement, severe ophthalmic disease, or cranial nerve complications requires IV therapy 1
Continue IV treatment for minimum 7-10 days and until all lesions have completely scabbed 1
Monitoring During IV Therapy
Monitor renal function closely at initiation and once or twice weekly during IV acyclovir treatment, with dose adjustments for renal impairment 1
Assess for thrombotic thrombocytopenic purpura/hemolytic uremic syndrome in immunocompromised patients receiving high-dose therapy 1
Special Populations
Immunocompromised Patients
For uncomplicated herpes zoster in immunocompromised patients: oral acyclovir 800 mg five times daily or valacyclovir 1000 mg three times daily, with consideration for higher doses or extended duration 1
For disseminated or invasive disease: IV acyclovir 10 mg/kg every 8 hours with temporary reduction in immunosuppressive medication 1
Immunocompromised patients may require treatment extension well beyond 7-10 days as lesions continue to develop over 7-14 days and heal more slowly 1
Renal Impairment
Creatinine clearance 30-49 mL/min: valacyclovir 1000 mg twice daily 2
Creatinine clearance 10-29 mL/min: valacyclovir 1000 mg once daily 2
Creatinine clearance <10 mL/min: valacyclovir 500 mg once daily 2
Dose adjustments are mandatory to prevent acute renal failure 1
Adjunctive Therapies
Corticosteroids: Limited Role
Prednisone may be used as adjunctive therapy in select cases of severe, widespread shingles, but offers only slight benefits over antiviral therapy alone 1, 7
A 21-day course of acyclovir or addition of prednisolone (40 mg daily, tapered over 3 weeks) confers only modest benefits in acute pain reduction with no reduction in postherpetic neuralgia 7
Avoid corticosteroids in immunocompromised patients due to increased risk of disseminated infection 1
Contraindicated in patients with poorly controlled diabetes, history of steroid-induced psychosis, severe osteoporosis, or prior severe steroid toxicity 1
Pain Management
Topical anesthetics provide minimal benefit and are not recommended as primary therapy 1
Tricyclic antidepressants or anticonvulsants in low doses may help control neuropathic pain 6
Narcotics may be required for adequate pain control in postherpetic neuralgia 6
Treatment Failures and Resistance
Acyclovir-Resistant Herpes Zoster
If lesions fail to resolve within 7-10 days despite treatment, suspect acyclovir resistance and obtain viral culture with susceptibility testing 1
For proven or suspected acyclovir-resistant herpes zoster: foscarnet 40 mg/kg IV every 8 hours until clinical resolution 1
All acyclovir-resistant strains are also resistant to valacyclovir, and most are resistant to famciclovir 1
Prevention
Vaccination
The recombinant zoster vaccine (Shingrix) is strongly recommended for all adults aged 50 years and older, regardless of prior herpes zoster episodes, reducing risk of future herpes zoster by over 90% 1
Vaccination should ideally occur before initiating immunosuppressive therapies 1
The vaccine can be considered after recovery from acute herpes zoster to prevent future episodes 1
Post-Exposure Prophylaxis
Varicella zoster immunoglobulin (VZIG) within 96 hours of exposure is recommended for varicella-susceptible patients exposed to active varicella zoster infection 1
If immunoglobulin is unavailable or >96 hours have passed, give a 7-day course of oral acyclovir beginning 7-10 days after exposure 1
Common Pitfalls to Avoid
Never use topical antiviral therapy alone—it is substantially less effective than systemic therapy and is not recommended 1, 8
Do not discontinue antiviral therapy at exactly 7 days if lesions are still forming or have not completely scabbed—treatment must continue until all lesions have scabbed 1
Do not delay treatment beyond 72 hours when possible—efficacy decreases significantly after this window 1, 2
Do not use corticosteroids routinely—they offer minimal benefit and carry significant risks, particularly in elderly and immunocompromised patients 1, 7