vidarabine

noun

vid·​ar·​a·​bine vid-ˈär-ə-ˌbēn 

: an antiviral agent C₁₀H₁₃N₅O₄·H₂O derived from adenine and arabinoside and used especially to treat keratitis and encephalitis caused by the herpes simplex virus

called also adenine arabinoside, ara-A