What is the recommended treatment for shingles?

Treatment of Herpes Zoster (Shingles)

For uncomplicated herpes zoster in immunocompetent adults, initiate oral valacyclovir 1000 mg three times daily or acyclovir 800 mg five times daily within 72 hours of rash onset, continuing treatment until all lesions have completely scabbed—typically 7-10 days. 1

First-Line Oral Antiviral Therapy

Valacyclovir 1000 mg orally three times daily for 7 days is the preferred first-line agent due to superior bioavailability and less frequent dosing compared to acyclovir, which improves patient adherence. 1

Alternative oral regimens include:

• Acyclovir 800 mg orally five times daily for 7-10 days remains effective but requires more frequent dosing. 1
• Famciclovir 500 mg orally three times daily for 7 days offers comparable efficacy with convenient dosing. 1

Critical Timing Window

• Treatment must be initiated within 72 hours of rash onset for optimal efficacy in reducing acute pain, accelerating lesion healing, and preventing postherpetic neuralgia. 1
• Even when presentation occurs after 72 hours, treatment should still be started because some clinical benefit may be realized. 1
• Treatment is most effective when initiated within 48 hours of rash onset, though the 72-hour window is the maximum timeframe for optimal efficacy. 1

Treatment Duration Endpoint

• Continue antiviral therapy until all lesions have completely scabbed, which is the key clinical endpoint—not an arbitrary 7-day duration. 1
• Treatment should be extended beyond 7-10 days if lesions remain active, as short-course therapy designed for genital herpes is inadequate for VZV infection. 1
• In immunocompetent patients, lesions typically continue to erupt for 4-6 days with total disease duration of approximately 2 weeks. 1

Indications for Intravenous Acyclovir

Switch to intravenous acyclovir 10 mg/kg every 8 hours when any of the following are present: 1

• Disseminated herpes zoster (≥3 dermatomes, visceral involvement, or hemorrhagic lesions) 1
• Severe immunosuppression (active chemotherapy, HIV with low CD4 count, organ transplant) 1
• CNS complications (encephalitis, meningitis, Guillain-Barré syndrome) 1
• Complicated facial or ophthalmic disease with risk of cranial nerve complications 1
• Inability to absorb oral medication 1
• Lack of clinical improvement after 7-10 days of oral therapy, suggesting possible acyclovir resistance 1

IV Therapy Duration and Monitoring

• Continue IV acyclovir for a minimum of 7-10 days and until clinical resolution (all lesions completely scabbed). 1
• Monitor renal function at initiation and once or twice weekly during IV therapy, with dose adjustments for renal impairment. 1
• Assess for thrombotic thrombocytopenic purpura/hemolytic uremic syndrome in immunocompromised patients receiving high-dose therapy. 1

Special Population: Immunocompromised Patients

For immunocompromised patients with uncomplicated herpes zoster, intravenous acyclovir 10 mg/kg every 8 hours is recommended due to high risk of dissemination and complications. 1

• Immunocompromised patients may develop new lesions for 7-14 days and heal more slowly, requiring treatment extension well beyond 7-10 days. 1
• Consider temporary reduction or discontinuation of immunosuppressive medications in cases of disseminated or invasive herpes zoster if clinically feasible. 1
• Re-introduction of immunosuppressive agents is recommended only after all vesicular lesions have crusted, fever has resolved, and the patient has shown clinical improvement. 1

Specific High-Risk Scenarios

• Patients on B-cell depleting therapies (ocrelizumab, rituximab, ofatumumab) are at highest risk and may require extended antiviral courses or IV therapy even when infection appears uncomplicated. 1
• Patients receiving proteasome inhibitor-based therapies (bortezomib) should receive acyclovir or valacyclovir prophylaxis to prevent herpes zoster. 1

Management of Acyclovir-Resistant Herpes Zoster

Suspect acyclovir resistance if lesions fail to improve within 7-10 days of appropriate therapy. 1

• Confirm resistance with viral culture and susceptibility testing. 1
• For confirmed acyclovir-resistant VZV, administer 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
• Topical cidofovir gel 1% applied once daily for 5 consecutive days may be an alternative option. 1
• Confirmed acyclovir-resistant VZV is rare in immunocompetent adults but occurs in up to 7% of immunocompromised patients. 1

Renal Dosing Adjustments

Assess baseline renal function before starting therapy and adjust dosing for creatinine clearance <50 mL/min to prevent nephrotoxicity. 1

Valacyclovir dose adjustments: 1

• CrCl 30-49 mL/min: 500 mg-1 g every 12 hours
• CrCl 10-29 mL/min: 500 mg-1 g every 24 hours
• CrCl <10 mL/min: 500 mg every 24 hours

Famciclovir dose adjustments: 1

• CrCl ≥60 mL/min: 500 mg every 8 hours
• CrCl <20 mL/min: 250 mg every 24 hours

Ensure adequate hydration during therapy to reduce risk of crystalluria and obstructive nephropathy, which occurs in up to 20% of patients. 1

Pain Management

Gabapentin is the first-line oral agent for acute neuropathic pain, titrated in divided doses up to 2400 mg per day. 1

• Gabapentin improves sleep quality but causes somnolence in approximately 80% of patients. 1
• Pregabalin may be added for uncontrolled pain, particularly in postherpetic neuralgia. 1
• A single application of an 8% capsaicin patch provides analgesia lasting at least 12 weeks for chronic peripheral neuropathic pain. 1
• Over-the-counter analgesics such as acetaminophen and ibuprofen are recommended for acute pain. 1
• Topical anesthetics provide minimal benefit and are not recommended as primary therapy. 1

Corticosteroids: Limited Role

• Prednisone may be used as adjunctive therapy to antivirals in select cases of severe, widespread shingles, but carries significant risks particularly in elderly patients. 1
• Prednisone should generally be avoided in immunocompromised patients due to increased risk of disseminated infection. 1
• Patients with poorly controlled diabetes, history of steroid-induced psychosis, severe osteoporosis, or prior severe steroid toxicity should avoid prednisone. 1

Infection Control Measures

Patients with herpes zoster should avoid contact with susceptible individuals until all lesions have crusted, as lesions are contagious to individuals who have not had chickenpox or vaccination. 1

• Cover lesions with clothing or dressings to minimize transmission risk. 1
• For disseminated zoster (≥3 dermatomes), implement both airborne and contact precautions. 1
• For immunocompromised patients, implement airborne and contact precautions due to higher risk of dissemination. 1
• Physical separation of at least 6 feet from other patients is recommended in healthcare settings. 1

Post-Exposure Prophylaxis

Administer varicella-zoster immune globulin (VZIG) within 96 hours of exposure to high-risk individuals including pregnant women, immunocompromised patients, and premature newborns <28 weeks gestation. 1

• If VZIG is unavailable or >96 hours have passed, initiate a 7-day course of oral acyclovir beginning 7-10 days after exposure. 1
• Varicella vaccine may be administered within 3-5 days of exposure to modify disease if infection has not yet occurred. 1

Vaccination for Prevention

The recombinant zoster vaccine (Shingrix) is strongly recommended for all adults aged ≥50 years, regardless of prior herpes zoster episodes, providing >90% efficacy in preventing future episodes. 2, 1

• Shingrix is also recommended for adults ≥18 years who are or will be at increased risk due to immunodeficiency or immunosuppression. 2
• The vaccine is administered as two 0.5 mL intramuscular injections 2-6 months apart. 2
• In immunocompromised individuals, spacing between injections may be reduced to 1-2 months. 2
• Where possible, administer the first dose at least 14 days before onset of immunosuppressive treatment. 2
• For patients on B-cell depleting therapy, give Shingrix at least 4 weeks prior to the next scheduled dose to maximize immunogenicity. 1
• The live-attenuated vaccine (Zostavax) is contraindicated in immunocompromised patients due to risk of uncontrolled viral replication. 2, 1

Therapies to Avoid

• Topical antiviral therapy is substantially less effective than systemic therapy and is not recommended. 1
• Do not use topical corticosteroid cream on active shingles rash, as it can increase risk of severe disease and dissemination, particularly in immunocompromised patients. 1
• Do not discontinue antiviral therapy at exactly 7 days if lesions are still forming or have not completely scabbed. 1