Medication Summary
The goals of pharmacotherapy are to reduce morbidity and to prevent complications. Current research is considering whether the varicella vaccine may also prove efficacious as treatment for active varicella-zoster virus (VZV) infection.
Antiviral agents
Class Summary
Three medications may help reduce pain and symptoms and the incidence of postherpetic neuralgia. All need to be used with caution in patients with renal compromise. Hemolytic uremic syndrome is rare but has been reported. All 3 agents may be used for 7-10 d, depending on response. Only acyclovir is available in an intravenous form.
Acyclovir (Zovirax)
Patients experience less pain and faster resolution of cutaneous lesions when used within 48 h from rash onset. May prevent recurrent outbreaks.
Valacyclovir (Valtrex)
Prodrug rapidly converted to the active drug acyclovir. More expensive but has a more convenient dosing regimen than acyclovir.
Famciclovir (Famvir)
Prodrug that, when biotransformed into active metabolite penciclovir, may inhibit viral DNA synthesis/replication.
Varicella Vaccines
Class Summary
These agents are used to induce active immunity.
The combined MMRV vaccine (ProQuad) is associated with an increased risk for febrile seizure occurring 5-12 days after vaccination at a rate of 1 in 2300-2600 in children aged 12-23 months compared with separate MMR vaccine and varicella vaccine administered simultaneously. [22, 23]
As a result, the CDC Advisory Committee on Immunization Practices (ACIP) recommends that separate MMR and varicella vaccines be used for the first dose, although providers or parents may opt to use the combined MMRV for the first dose after counseling regarding this risk. [24]
MMRV is preferred for the second dose (at any age) or the first dose if given at age 48 months or older.
Data from post-licensure studies do not suggest that children aged 4-6 years who received the second dose of MMRV vaccine had an increased risk for febrile seizures after vaccination compared with children the same age who received MMR vaccine and varicella vaccine administered as separate injections at the same visit. [24]
Varicella virus vaccine (Varivax)
A live attenuated varicella virus prepared from the Oka/Merck strain. It is propagated in human diploid cell cultures (MRC-5). Each 0.5-mL dose (when reconstituted) contains 1350 PFU of varicella, sucrose, and gelatin; residual components of MRC-5 DNA and protein; and trace quantities of neomycin and fetal bovine serum. Indicated for vaccination against varicella in individuals >1 y.
Zoster Vaccines
Class Summary
These agents are used to induce active immunity.
In October 2017, the FDA approved zoster vaccine recombinant, adjuvanted (Shingrix) for the prevention of shingles in adults aged 50 years or older. The approval is based on findings from a phase III clinical trial program assessing its efficacy, safety, and immunogenicity in 38,000 patients. Data from a pooled analysis of two clinical trials demonstrated efficacy against shingles at greater than 90% across all age groups, as well as sustained efficacy over a follow-up period of 4 years. [20, 21]
Zoster vaccine recombinant (Shingrix)
Non-live recombinant subunit vaccine intended for IM injection in 2 doses. It consists of glycoprotein E, an antigen, and AS01B, an adjuvant system, intended to induce a strong and sustained immune response to help overcome reduced immunity that comes with age. Indicated for the prevention of shingles (herpes zoster) in adults aged 50 years or older.
Topical Analgesics
Class Summary
Topical analgesics that contain capsaicin are effective in decreasing neuropathic pain caused by postherpetic neuralgia.
Capsaicin transdermal patch (Qutenza)
Transient receptor potential vanilloid-1 (TRPV1) agonist indicated for neuropathic pain associated with postherpetic neuralgia. TRPV1 is an ion channel–receptor complex expressed on nociceptive skin nerve fibers. Topical capsaicin causes initial TRPV1 stimulation that may cause pain, followed by pain relief by reduction in TRPV1-expressing nociceptive nerve endings. Neuropathic pain may gradually recur over several months (thought to be caused by TRPV1 nerve fiber reinnervation of treated area).
Immune Globulins
Class Summary
The specific immune globulin with IgG varicella zoster antibodies provides passive immunization for susceptible individuals when administered within 10 days (ideally within 96 hours) of exposure.
Varicella zoster immune globulin, human (VariZIG)
Varicella zoster immune globulin (VZIG) contains immunoglobulin G (IgG) varicella-zoster antibodies. It provides passive immunization to exposed individuals at high risk of complications from varicella. High- risk groups include immunocompromised children and adults, newborns of mothers with varicella shortly before or after delivery, premature infants, infants < 1 year, adults without evidence of immunity, and pregnant women. Administer by deep IM injection, preferably in deltoid muscle. For neonates or infants, administer IM in anterolateral aspect of thigh.
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Typical zoster in the vicinity of right popliteal fossa in a vertebral nerve L4 distribution.
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Human herpesvirus (HHV) type 3. Intraoral herpes zoster closely resembles recurrent HHV-1 infection, but the lesions generally follow a dermatome and stop sharply at the midline, as shown here. However, the rules for common sites of occurrence of HHV-1 and HHV-3 often do not apply to patients who are immunocompromised. Courtesy of Sheldon Mintz, DDS.
