NCIt definition : A phosphate salt form of vidarabine, a nucleoside analog with activity against herpes
simplex virus and varicella zoster virus. Vidarabine is converted to a monophosphate
by viral thymidine kinase and is further modified to a triphosphate form by host enzymes.
Vidarabine triphosphate directly inhibits DNA polymerase and also acts as a chain
terminator in DNA replication.;