The antiviral drug valaciclovir is used to treat herpes conditions, including shingles. It is marketed under the trade names Valtrex and Zelitrex and has been sold as a generic since 2009.
Valaciclovir is actually a prodrug; after it is taken orally, it is converted by esterase enzymes to the active drug aciclovir, a viral DNA polymerase inhibitor. Valaciclovir’s advantage is that it is more bioavailable than aciclovir.
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