High Quality Content by WIKIPEDIA articles! Valaciclovir (INN) or valacyclovir (USAN) is an antiviral drug used in the management of herpes simplex, herpes zoster (shingles), and herpes B. It is a prodrug, being converted in vivo to aciclovir. It is marketed by GlaxoSmithKline under the trade names Valtrex and Zelitrex. As of November 25, 2009 (2009 -11-25), valacyclovir is marketed in generic form in the United States by Ranbaxy Laboratories.