valacyclovir, Valtrex

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GENERIC NAME: valacyclovir

BRAND NAME: Valtrex

DRUG CLASS AND MECHANISM: Valacyclovir is an oral antiviral drug which is active against the herpes viruses. It is used to treat infections with shingles (herpes zoster), genital herpes (herpes simplex genitalis), and cold sores (herpes labialis). It belongs to a class of drugs called nucleoside analogs that mimic one of the building blocks of DNA. It stops the spread of herpes virus in the body by preventing the replication of viral DNA that is necessary for viruses to multiply. Other drugs in the same class include acyclovir (Zovirax) and famciclovir (Famvir). Valacyclovir is actually a "prodrug," in that it is not active itself. Rather, it is converted to acyclovirin the body, and it is the acyclovir that is active against the viruses. (Acyclovir itself is available as a topical, oral and intravenous medication.) Valacyclovir, therefore, is active against the same viruses as acyclovir, but valacyclovir has a longer duration of action than acyclovir, and, therefore, can be taken fewer times each day. Valacyclovir was approved for use by the FDA in 1995.

Medically Reviewed by a Doctor on 8/8/2013



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