Aciclovir antiviral activity

Wagstaff AJ, Faulds D, Goa KL (1994) Aciclovir a reappraisal of its antiviral activity, pharmacokinetic properties and therapeutic efficacy. Drugs 47 153—205. 

Aciclovir is an acyclic purine nucleoside. Its antiviral activity depends upon intracellular phosphorylation to its triphosphate derivative. Because of its higher affinity for viral thymidine kinase, aciclovir is phosphorylated at a much higher rate by the viral enzyme. Thus, it is almost exclusively active in infected cells, fulfilling one of the selectivity principles of antiviral drugs. In addition, aciclovir triphosphate serves as a better substrate for viral than for host cell DNA polymerase and thereby causes preferential termination of viral DNA sjmthesis (1). 

Its antiviral activity and effectiveness are similar to that of aciclovir. 

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