Skip to content

Famciclovir

Famciclovir, sold as Famvir, is an antiviral used to treat shingles and recurrent cold sores. The listing covers 250 mg and 500 mg film-coated tablets.

Famvir

Herpes Zoster, Herpes Simplex Virus Infections

250mg · 500mg

Famciclovir tablets for shingles and cold sores. It becomes active inside infected cells to stop the virus multiplying.

From$4.42/ tabletView

Key points

  • Penciclovir is the active form: famciclovir converts to it in the body, where it stops herpesvirus DNA from replicating.
  • Famvir is the brand-name version of famciclovir, marketed by Novartis, and the only product listed here.
  • Kidney function affects how much penciclovir stays in the body, so impaired kidneys can require a different dose.

How does famciclovir work?

Famciclovir is a prodrug, meaning it is inactive until the body converts it to penciclovir. Penciclovir then enters infected cells and blocks the enzyme herpesvirus needs to copy its DNA. Without that copy step, the virus cannot make new copies of itself.

Famvir is listed for Herpes Zoster, Herpes Simplex Virus Infections, and varicella, within the Antivirals category.

Further reading