Sounds like 'ten-off-oh-veer'

Tenofovir is used to treat infections caused by viruses such as hepatitis B infection. Find out how to take it safely and possible side effects.

Type of medicine Also called
  • For hepatitis B
  • Antiviral
  • Tenofovir disoproxil (Teva)®

What is tenofovir?

Tenofovir is used to treat long-term hepatitis B infection. It is called an antiviral medicine. Tenofovir works by stopping the hepatitis B virus from multiplying and in this way reduces the amount of the virus in your body. It is used for the treatment of chronic hepatitis B and HIV infection and for pregnant women who have chronic hepatitis B.

Tenofovir is not a cure for hepatitis B. It does not prevent the spread of the virus to others through sexual contact or blood or body fluid contamination, such as sharing used needles. Read more about chronic hepatitis B.

In New Zealand tenofovir is available as tablets (245 mg). 

Tenofovir is also available in combination with other medicines to control HIV, eg, Truvada (tenofovir +  emtricitabine) and Atripla (tenofovir +  emtricitabine + efavirenz).

Dose of tenofovir

  • The usual dose of tenofovir is 245 mg (1 tablet) once a day.
  • Your doctor will advise you how long to take tenofovir for.
  • Always take your tenofovir exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much to take, how often to take it and any special instructions.

How to take tenofovir

  • Swallow your tenofovir tablet whole with a glass of water.
  • Tenofovir is best taken with food.
  • Try taking your dose about the same time each day.
  • Limit or avoid alcohol while taking tenofovir. Alcohol may worsen liver problems.   
  • If you forget to take your dose, take it as soon as you remember. But, if it is nearly time for your next dose, take your next dose at the usual time. Do not take double the dose.
  • Keep taking your tenofovir for the full time it has been prescribed, even if you feel well.
  • You will need regular blood tests while taking tenofovir to check how well the medicine is working for you and to make sure your kidneys are working well.

Precautions before starting tenofovir

  • Are you pregnant, planning a pregnancy or breastfeeding?
  • Do you have problems with your kidneys?
  • Do you have HIV infection?
  • Are you taking any other medicines? This includes any medicines you buy without a prescription, such as herbal and complementary medicines.

If so, it’s important that you tell your doctor or pharmacist before you start tenofovir. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care. 

What are the side effects of tenofovir?

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

Lactic acidosis

Tenofovir can very rarely cause a condition called lactic acidosis. You are at highest risk if you have severe liver or kidney problems. Contact your doctor immediately if you are being sick (vomiting) or feel very unwell, have muscle cramps or become unusually tired, or if you feel short of breath and your breathing becomes faster than normal – these are the signs of lactic acidosis.

Side effects What should I do?
  • Nausea (feeling sick) 
  • Vomiting (being sick)
  • Indigestion
  • Diarrhoea (runny poos)
  • Headache
  • Feeling tired
  • Dizziness
  • Cough
  • Difficulty sleeping
  • These are quite common when you first start taking tenofovir and usually get better with time. 
  • Tell your doctor if troublesome or these side effects don't go away.
  • Signs of an allergic reaction such as skin rash, itching, swelling of your lips, face and mouth or difficulty breathing
  • Tell your doctor immediately or phone Healthline 0800 611 116.
Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product

Learn more about tenofovir

The following links have more information on tenofovir.

Hepatitis B treatment Hepatitis Foundation, NZ 
New Zealand Formulary
Tenofovir disoproxil (Teva) Medsafe Consumer Information


  1. Tenofovir disoproxil New Zealand Formulary
  2. Hepatitis B: treatments now available for primary care BPAC, NZ, 2018
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 15 Aug 2019