Comparison of the in vitro and in vivo antiherpes virus activities of the acyclic nucleosides, acyclovir (Zovirax) and 9-[(2-hydroxy-1-hydroxymethylethoxy)methyl]guanine (BWB759U).

The antiherpes virus activities of acyclovir and its close analogue 3-[(2-hydroxy-1-hydroxymethylethoxy)methyl]guanine (BWB759U) were compared in vitro and in vivo. The activities of both compounds against herpes simplex virus and varicella-zoster virus were similar in the majority of cell lines. However, in mouse-derived and HeLa cells, BSB759U was more effective than acyclovir against herpes simplex virus. Mutants of herpes simplex virus deficient in thymidine kinase and resistant to acyclovir were found to vary in their sensitivity to BWB759U. In two mouse models of herpes simplex virus infection BWB759U was more effective than acyclovir.