Acyclovir: Evaluation of a new antiviral agent

Acyclovir

“…3 A highly potent inhibitor of viral DNA polymerases, the active form of the drug, causes an inhibition of viral replication. 4 In addition to polymerase inhibition, the activated acyclovir is also incorporated into the growing strand of DNA. Because of this structural difference, the DNA template is terminated.…”

“…One study of varicella-zoster infected patients who had received topical applications of acyclovir reported blood levels of approximately 1 |ig/ml. 4 Orally administered acyclovir is poorly absorbed from the gastrointestinal tract. 7 The peak plasma concentration is reached within 1.5 to 2 hours of administration; with continued administration, steady-state is reached within 1 to 2 days.…”

“…It should be emphasized that at present this resistance is of unknown clinical significance. 4 Resistant strains are readily produced in the laboratory; 1 however, their existence in vivo is much less apparent, perhaps meriting consideration only in the immunocompromised patient. One mechanism by which viruses become resistant is through the loss of their ability to induce selective thymidine kinase, resulting in an inability to phosphorylate acyclovir.…”

“…1 A second mechanism of resistance involves production of altered DNA polymerase by the resistant virus, resulting in a decreased ability to recognize acyclovir triphosphate as a substrate. 4 Although more studies are necessary, because of the potential for resistance, long-term use of acyclovir may raise some concerns.…”

Estudo farmacológico, eletrofisiológico, imunocitoquímico e morfológico da injeção intravítrea de aciclovir em coelhos

“…137 A concentração inibitória mínima de aciclovir para inibir 50% dos vírus da família herpes varia de acordo com os tipos de ensaios usados, e com o vírus, apesar da droga agir contra todos os espécies da família, como vírus herpes simplex tipos 1 e 2, vírus varicela zoster e vírus Epstein-Baar. 4,60,61 Herpes simplex precisam de menor concentração, enquanto o vírus varicela zoster precisar de mais, justificado pela posologia usada sistemicamente no início do tratamento. Mesmo assim, a concentração de 0,1mg/0,1ml é suficiente para esse tratamento local.…”