title: Once, twice, or three times daily famciclovir compared with aciclovir for the oral treatment of herpes zoster in immunocompetent adults: a randomized, multicenter, double-blind clinical trial.
abstract: BACKGROUND
  Famciclovir, the well absorbed oral pro-drug of penciclovir, is effective in the treatment of herpes zoster when given three times daily. Because the intracellular half-life of penciclovir triphosphate in varicella-zoster virus (VZV)-infected cells (7h) is considerably longer than that of aciclovir triphosphate (1h), it may be possible to administer famciclovir less frequently than three times daily for herpes zoster: aciclovir is administered five times daily.
  
  
  METHODS
  559 immunocompetent adults presenting with herpes zoster whose skin lesions were present for less than 72 h were randomized to receive famciclovir 750 mg once daily (od), 500 mg twice daily (bid), or 250 mg three times daily (tid), or aciclovir 800 mg five times daily. All treatments were given for 7 days. Participants were evaluated until complete healing or for 4 weeks, whichever occurred first.
  
  
  RESULTS
  There were no significant differences between the four treatment groups with respect to times to full crusting; loss of vesicles, ulcers and crusts; cessation of new lesion formation; a 50% reduction in the area of affected skin; and the loss of acute pain.
  
  
  CONCLUSIONS
  Famciclovir 750 mg once daily, 500 mg twice daily and 250 mg daily, and aciclovir 800 mg five times daily are three times comparable in efficacy with respect to the cutaneous healing of herpes zoster. The current study was not designed to assess the effects of the treatments on postherpetic neuralgia (PHN).
authors.affiliation: Division of Infectious Diseases, Department of Medicine, 2E4.16 Walter C. Mackenzie Health Sciences Centre, University of Alberta Hospital, 8440-112 Street, Edmonton, Alta., Canada T6G 2B7. sshafran@ualberta.ca
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Shafran
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Tyring
authors.forename: Richard
authors.initials: R
authors.lastname: Ashton
authors.forename: Jacque
authors.initials: J
authors.lastname: Decroix
authors.forename: Chistine
authors.initials: C
authors.lastname: Forszpaniak
authors.forename: Alan
authors.initials: A
authors.lastname: Wade
authors.forename: Christian
authors.initials: C
authors.lastname: Paulet
authors.forename: Daniel
authors.initials: D
authors.lastname: Candaele
mesh_terms: D015075:2-Aminopurine / Q000008:administration & dosage* / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D000212:Acyclovir / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D004311:Double-Blind Method; D000077595:Famciclovir; D005260:Female; D006562:Herpes Zoster / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009437:Neuralgia; D010146:Pain; D012867:Skin / Q000473:pathology
chemical_list: D000998:Antiviral Agents; D015075:2-Aminopurine; D000077595:Famciclovir; D000212:Acyclovir