Comparative Efficacy of Antiberpes Drugs Against Various Strains of Varicella-Zoster Virus

Abstract

Twenty antiherpes compounds were compared for their inhibitory activities against five laboratory strains and five clinical isolates of varicella-zoster virus (VZV)in human embryo fibroblast cultures. E-5-(2-bromovinyl)-1-β-d-arabinofuranosyluracil (BVaraU), E-5-(2-iodovinyl)-2′-deoxyuridine (IVDU), and E-5-(2-bromovinyl)-2′-deoxyuridine (BVDU) were the most effective. The average values of the 50% inhibitory dose (ID₅₀) for VZV replication were 0.0013, 0.0015, and 0.0024 µg/ml, respectively. I-β-d-Arabinofuranosyladenine and 9-(2-hydroxyethoxymethyl)guanine were 1.2 and 3.4 times less effective than 5-iodo-2′-deoxyuridine (IDU). The selectivity indexes (ratio of ID₅₀ for host-cell DNA synthesis to IDso for VZV replication) of BVaraU, IVDU, and BVDU were between 41,000 and 67,000, whereas those of cytosine arabinoside, IDU, and 5-bromo-2′-deoxyuridine were 50 for strains that were not deficient.