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DOSAGE
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Herpes Zoster: 1 gram PO TID x 7-10 days
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Herpes Simplex: 500mg PO TID x 7-10 days
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GENERIC
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valacyclovir
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SIZE
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500mg, 1gm
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TREATMENT REGIMEN
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HERPES ZOSTER
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HERPES SIMPLEX
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Conjunctivitis: (1) Oral Antiviral (Choose one): Acyclovir 800 mg PO 5x/day x 7-10 days, Valacyclovir 1000mg PO TID x 7-10 days or Famciclovir 500mg PO TID x 7-10 days (2) Cool compresses BID (3) Erythromycin ung BID
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Conjunctivitis: (1) Topical Antiviral (Choose one): Viroptic 1% 5x/day x 7 days or Zirgan 0.15% (gel) 5/day x 7 days
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SPK Cornea: (1) Oral Antiviral (Choose one): Acyclovir 800 mg PO 5x/day x 7-10 days, Valacyclovir 1000mg PO TID x 7-10 days or Famciclovir 500mg PO TID x 7-10 days (2) Preservative-free artificial tears q1-2hrs + ung qHS
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Cornea Epithelial Dendrites (1) Topical Antiviral (Choose one): Viroptic 1% 9x/day x 7 days or Zirgan 0.15% (gel) 5x/day x 7 days (2) Oral Antiviral (choose one): Acyclovir 400 mg PO 5x/day x 7-10 days, Valacyclovir 500mg PO TID x 7-10 days or Famciclovir 250mg PO TID x 7-10 days (3) Consider Cyclopentolate 1% TID if AC reaction or photophobia (4) DO NOT use topical steroids with epithelial
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Cornea Pseudodendrites: (1) Oral Antiviral (Choose one): Acyclovir 800 mg PO 5x/day x 7-10 days, Valacyclovir 1000mg PO TID x 7-10 days or Famciclovir 500mg PO TID x 7-10 days (2) Preservative-free artificial tears q1-2hrs + ung qHS (3) Topical antiviral: Zirgan 0.15% (gel) TID-QID x 7-10 days
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Cornea Stromal (Disciform Keratitis) (1) Cyclopentolate 1% TID (2) Antiviral prophylaxis Oral (choose one): Acyclovir 400 mg PO BID or Valacyclovir 500mg PO qDay to BID (3) Antiviral prophylaxis Drops (choose one): Viroptic 1% TID or Zirgan 0.15% (gel) 3-5x/day (4) If moderate/Severe with central vision loss: Add on Predforte 1% q2hr to QID
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Stromal Cornea Keratitis: (1) Oral Antiviral (Choose one): Acyclovir 800 mg PO 5x/day x 7-10 days, Valacyclovir 1000mg PO TID x 7-10 days or Famciclovir 500mg PO TID x 7-10 days (2) Predforte 1% 4-8/day, then taper, usually with weaker steroid with goal of q1week.
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INDICATIONS
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Valacyclovir is active against Varicella Zoster(VZV), and is about twice as effective against HSV-1 and HSV-2
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MECHANISM OF ACTION
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guanine analogue antiviral: pro-drug of acyclovir
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MICROBIOLOGY
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Valacyclovir is a deoxynucleoside analogue DNA polymerase inhibitor. Valacyclovir hydrochloride is rapidly converted to acyclovir, which has demonstrated antiviral activity against HSV types 1 (HSV‑1) and 2 (HSV‑2) and VZV both in cell culture and in vivo. Acyclovir is a synthetic purine deoxynucleoside that is phosphorylated intracellularly by the viral encoded thymidine kinase (TK; pUL23) of HSV or VZV into acyclovir monophosphate, a nucleotide analogue. The monophosphate is further converted into diphosphate by cellular guanylate kinase and into triphosphate by a number of cellular enzymes. In biochemical assays, acyclovir triphosphate inhibits replication of α-herpes viral DNA. This is accomplished in 3 ways: 1) competitive inhibition of viral DNA polymerase, 2) incorporation and termination of the growing viral DNA chain, and 3) inactivation of the viral DNA polymerase. The greater antiviral activity of acyclovir against HSV compared with VZV is due to its more efficient phosphorylation by the viral TK.
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CONTRAINDICATIONS & WARNINGS
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VALTREX is contraindicated in patients who have had a demonstrated clinically significant hypersensitivity reaction (e.g., anaphylaxis) to valacyclovir, acyclovir, or any component of the formulation
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PEDIATRIC USE
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The efficacy and safety of valacyclovir have not been established in pediatric patients: aged less than 12 years with cold sores, aged less than 18 years with genital herpes, aged less than 18 years with herpes zoster, aged less than 2 years with chickenpox, for suppressive therapy following neonatal HSV infection.
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PREGNANCY
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Category B | Clinical data over several decades with valacyclovir and its metabolite, acyclovir, in pregnant women, have not identified a drug associated risk of major birth defects. There are insufficient data on the use of valacyclovir regarding miscarriage or adverse maternal or fetal outcomes
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NOTE
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Steroids are indicated for HSV stromal keratitis but must be avoided in the acute phase of active viral replication on the ocular surface as in acute epithelial keratitis.
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