Famciclovir is an antiviral medication. After you take it, your body converts it into penciclovir, which is the active form. Penciclovir works by blocking the action of an enzyme called DNA polymerase in certain viruses, specifically herpes viruses like herpes simplex virus (HSV) and varicella zoster virus (VZV). By blocking this enzyme, famciclovir prevents the virus from making new copies of itself, which helps to control the infection and reduce symptoms.

In people with weakened immune systems, such as those with blood cancers or HIV, herpes virus infections can be more frequent and severe. Famciclovir helps to reduce the number and severity of outbreaks, and can also be used to suppress ongoing viral activity. While it does not cure herpes infections, it helps manage the symptoms and reduce the risk of complications.

Famciclovir

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Approved use in