famciclovir, Famvir (cont.)

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PREPARATIONS: Tablets: 125, 250, and 500 mg STORAGE: Famciclovir should be stored at room temperature, 15-30 C (59-86 F).

PRESCRIBED FOR: Famciclovir is used for the treatment of genital herpes, and cold sores in adult patients with normal immune systems and HIV-infected individuals. It also is approved for treating shingles (herpes zoster) in adults with normal immune systems. To be most effective, famciclovir should be started as soon as possible after the diagnosis of a herpes infection.

DOSING: Famciclovir may be taken with or without food. The recommended doses are:

  • Recurrent genital herpes: 1,000 mg every 12 hours for one day.
  • Recurrent cold sores: 1,500 mg as a single dose.
  • Suppression of recurrent genital herpes: 250 mg twice daily.
  • Shingles: 500 mg every 8 hours for 7 days.
  • HIV-infected patients (cold sores or genital herpes): 500 mg twice daily for 7 days.

DRUG INTERACTIONS: Probenecid (Benemid) may reduce the kidney's removal of famciclovir leading to higher concentrations of famciclovir in the blood. This may lead to side effects from famciclovir.

PREGNANCY: Famciclovir has not been adequately studied in pregnant women.

NURSING MOTHERS: It is not known if famciclovir is excreted into human breast milk. Women may wish to consider an alternative to breastfeeding if famciclovir is taken.

SIDE EFFECTS: The most common side effects associated with the use of famciclovir are headache, fatigue, nausea, vomiting, rash, diarrhea, and flatulence. Serious but rare side effects include serious allergic reactions, serious skin reactions, jaundice, abnormal tests of liver function, and reduced white blood cells (neutropenia) or platelets (thrombocytopenia). Cases of kidney failure have been reported when higher than recommended doses of famciclovir were administered to patients with underlying kidney problems.

Reference: FDA Prescribing Information

Last Editorial Review: 3/9/2012

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