What is the recommended treatment for Herpes zoster (shingles)?

Treatment of Herpes Zoster (Shingles)

For uncomplicated herpes zoster, initiate oral valacyclovir 1 gram three times daily for 7 days, starting within 72 hours of rash onset, and continue treatment until all lesions have completely scabbed. 1, 2

First-Line Oral Antiviral Therapy

Valacyclovir is the preferred first-line agent due to superior bioavailability and convenient dosing compared to acyclovir. 2, 3

Standard Dosing Regimens:

• Valacyclovir: 1000 mg orally three times daily for 7 days 1, 2, 3
• Famciclovir: 500 mg orally three times daily for 7 days 1, 4
• Acyclovir: 800 mg orally five times daily for 7 days 1, 2

Critical Timing Considerations:

• Initiate treatment within 72 hours of rash onset for optimal efficacy in reducing acute pain duration and preventing postherpetic neuralgia 1, 3, 5
• Treatment initiated within 48 hours provides maximum benefit 1
• Continue therapy until all lesions have completely scabbed, not just for an arbitrary 7-day period—this is the key clinical endpoint 1, 2
• Treatment beyond 72 hours may still provide benefit, particularly in immunocompromised patients or those with ongoing lesion formation 1

Indications for Intravenous Acyclovir

Escalate to IV acyclovir 5-10 mg/kg every 8 hours for the following presentations: 1, 2

• Disseminated herpes zoster (multi-dermatomal or visceral involvement) 1, 2
• Ophthalmic zoster with suspected CNS involvement 1
• Severe immunocompromised state 1, 6
• Inability to tolerate oral medications 6
• Patients requiring hospitalization due to severe disease 2

Continue IV therapy until clinical improvement occurs, then switch to oral therapy to complete the treatment course. 2

Special Population Considerations

Immunocompromised Patients:

• All immunocompromised patients require antiviral treatment regardless of timing beyond the 72-hour window 2
• Consider temporary reduction or discontinuation of immunosuppressive medications in cases of disseminated or invasive disease 1, 2
• Immunosuppression may be restarted after commencing anti-VZV therapy and resolution of skin vesicles 2
• Monitor closely for dissemination and visceral complications 2

Facial/Ophthalmic Involvement:

• Facial zoster requires urgent treatment due to risk of ophthalmic and cranial nerve complications 1
• Initiate valacyclovir 1 gram three times daily or famciclovir 500 mg three times daily immediately 1
• Consider ophthalmology referral for ophthalmic involvement 7

Renal Impairment:

• Dose adjustment is mandatory to prevent acute renal failure 4, 3
• For creatinine clearance 20-39 mL/min: valacyclovir 500 mg every 24 hours 3
• For creatinine clearance <20 mL/min: valacyclovir 250 mg every 24 hours 3
• Monitor renal function closely during IV acyclovir therapy 1

Acyclovir-Resistant Cases

For suspected acyclovir-resistant herpes zoster, switch to foscarnet 40 mg/kg IV every 8 hours, as acyclovir-resistant isolates are routinely cross-resistant to ganciclovir. 2

Pain Management

Combine antiviral therapy with appropriate analgesics from the outset to control acute zoster pain and reduce risk of postherpetic neuralgia. 5, 6

• Consider adding a neuroactive agent such as amitriptyline early in the treatment course 5
• Gabapentin or pregabalin may be beneficial for neuropathic pain control 8
• Topical lidocaine patches can provide localized relief 7

Role of Corticosteroids:

• Corticosteroids may provide modest benefit in reducing acute pain but do not significantly prevent postherpetic neuralgia 7, 5
• Use cautiously and only as adjunctive therapy in select cases 1
• Avoid in immunocompromised patients due to increased risk of disseminated infection 1

Prevention Strategies

Post-Exposure Prophylaxis:

• Administer varicella zoster immunoglobulin within 96 hours of exposure for varicella-susceptible patients exposed to active infection 1, 2
• If immunoglobulin unavailable or >96 hours elapsed: initiate 7-day course of oral acyclovir beginning 7-10 days after exposure 1, 2

Vaccination:

• The recombinant zoster vaccine (Shingrix) is recommended for all adults ≥50 years regardless of prior herpes zoster episodes 1, 2
• Ideally administer before initiating immunosuppressive therapies 1

Common Pitfalls to Avoid

• Do not rely on the 72-hour window as an absolute cutoff—immunocompromised patients and those with ongoing lesion formation benefit from treatment initiated later 1, 2
• Do not stop treatment at 7 days if lesions have not fully scabbed—continue until complete crusting occurs 1, 2
• Do not use topical antiviral therapy alone—it is substantially less effective than systemic therapy 1
• Do not forget dose adjustment in renal impairment—inappropriately high doses cause acute renal failure 4, 3
• Do not delay treatment in facial zoster—ophthalmic complications require urgent intervention 1