Famciclovir

Sounds like 'fam-SYE-kloe-vir'

Easy-to-read medicine information about famciclovir – what is it, how to take famciclovir safely and possible side effects.

Type of medicine Also called
  • Antiviral (to treat infections caused by viruses)


  • Famvir Once®


What is famciclovir?

  • Famciclovir is used to treat recurrent cold sores, around the mouth, lips, nostrils or nose. 
  • It must be used as possible after the first symptoms and signs of a cold sore appear such as tingling, itching, burning, redness, or swelling.
  • Famciclovir should not be used if a hard crust has already formed on the cold sore.
  • It works by stopping the growth of the viruses that cause the infection. In this way famciclovir reduces the severity of the infection, and stops it from spreading. It helps the infection heal faster. Famciclovir does not kill the virus. The virus that cause this infection continues to live in the body.
  • Famciclovir is not subsidized in New Zealand. It can be purchased from your pharmacy, without a prescription, for the treatment of recurrent cold sores.
  • Talk to your pharmacist to check if famciclovir is suitable for you.  
  • Famciclovir is available as tablets (500 milligrams).

Dose

  • The dose of famciclovir is three tablets taken together as a single dose (= 1500 milligrams). 
  • Always take your famciclovir exactly as directed by your doctor your pharmacist. The pharmacy label on your medicine will tell you how much famciclovir to take, how often to take it, and any special instructions.

How to take famciclovir

  • Swallow your famciclovir tablets with a glass of water.
  • Take three famciclovir tablets together as a single dose 
  • You can take famciclovir with or without food.
  • Drink plenty of water while taking famciclovir, to keep your kidneys working well (unless your doctor advises you otherwise). 

Possible side effects

Like all medicines, famciclovir can cause unwanted side effects, although not everyone gets them. Often unwanted side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Headache
  • Nausea (feeling sick)
  • Diarrhoea (loose, watery stools)    
  • This may settle after a few hours


  • Signs of an allergic reaction such as skin rash, itching, swelling of the lips, face, and mouth or difficulty breathing
  • Tell your doctor immediately or ring HealthLine 0800 611 116

Learn more

The following links provide further information on famciclovir. Be aware that websites from other countries may contain information that differs from New Zealand recommendations.

Apo-Famciclovir Medsafe NZ Consumer Medicine Information

 

Credits: Sandra Ponen, Pharmacist. Reviewed By: Dr J Bycroft