title: Comparative efficacy of acyclovir and vidarabine on the replication of varicella-zoster virus.
abstract: Acyclovir and less frequently, vidarabine are (or have been) used in the treatment of varicella-zoster virus (VZV) infection and are administered either intravenously (vidarabine) or orally (acyclovir, up to five times per day). The pharmacological bases of the administration interval were modeled in vitro in this study. Incubation of VZV-infected cultures with acyclovir or vidarabine for 24, 48, 72 and 96h showed similar duration-dependent anti-viral activities as assessed by a plaque-reduction assay. Treatment with vidarabine for only 8h/day for 4 days (intermittent treatment) showed anti-VZV activity equivalent to that of continuous treatment for 4 days in terms of the inhibitory dose that reduced plaque formation by 50% (IC(50)). In contrast, intermittent treatment with acyclovir exhibited a 7.9 times higher IC(50) value than that of continuous treatment. The mode of inhibition of expression of most of viral protein was similar in both drugs, but the degree of inhibition was different for each protein. Thus, vidarabine with a limited period of treatment showed anti-VZV activity comparable to continuous treatment with acyclovir, indicating the longer duration of anti-viral activity of vidarabine.
authors.affiliation: Department of Virology, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Miwa
authors.forename: Kunikazu
authors.initials: K
authors.lastname: Kurosaki
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Yoshida
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kurokawa
authors.forename: Shigeru
authors.initials: S
authors.lastname: Saito
authors.forename: Kimiyasu
authors.initials: K
authors.lastname: Shiraki
mesh_terms: D000212:Acyclovir / Q000494:pharmacology*; D000998:Antiviral Agents / Q000494:pharmacology*; D002460:Cell Line; D014645:Herpesvirus 3, Human / Q000187:drug effects*; D006801:Humans; D014740:Vidarabine / Q000494:pharmacology*; D010948:Viral Plaque Assay; D014764:Viral Proteins / Q000378:metabolism; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D014764:Viral Proteins; D014740:Vidarabine; D000212:Acyclovir