Tenofovir for hepatitis B infection

About tenofovir for hepatitis B infection

Tenofovir is an antiviral medicine. It belongs to a group of medicines known as nucleoside reverse transcriptase inhibitors (NRTIs).

Hepatitis B is a virus which is carried in your bloodstream to your liver, where it can cause inflammation and damage. Following infection with hepatitis B, a few people develop a persistent infection called chronic hepatitis B, and will usually need treatment to reduce the activity of the virus. This limits damage to the liver, which is a complication of the infection. Antiviral medicines like tenofovir work by stopping the hepatitis B virus from multiplying (replicating), this reduces the amount of the virus in your body. A doctor who is a liver specialist will usually start the treatment for you. Treatment for chronic hepatitis B usually continues for several years and can include more than one antiviral medicine.

Tenofovir is also prescribed for another viral infection - there is more information about this in a separate medicine leaflet called Tenofovir for HIV.

Before taking tenofovir

Some medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken. For these reasons, before you start taking tenofovir it is important that your doctor knows:

• If you are pregnant, trying for a baby or breastfeeding.

• If you have any problems with the way your liver works, or if you have problems with the way your kidneys work.

• If you have a condition which weakens your bones, such as osteoporosis, or you are at risk of bone fractures.

• If you drink a lot of alcohol.

• If you are taking any other medicines. This includes any medicines which are available to buy without a prescription, as well as herbal and complementary medicines.

• If you have ever had an allergic reaction to a medicine.

How to take tenofovir for hepatitis B infection

• Before you start the treatment, read the manufacturer's printed information leaflet from inside your pack. It will give you more information about tenofovir, and it will also provide you with a full list of the side-effects which you could experience from taking it.

• Take tenofovir exactly as your doctor tells you to. The usual dose for an adult is one 245 mg tablet daily.

• Swallow the tablet whole with a drink of water. If you have difficulty swallowing tablets, please let your doctor know about this as it may be more suitable for you to be prescribed tenofovir as granules. In the meantime, if necessary, you can crush the tablet and add it to half a glass of water, orange juice or grape juice, providing you swallow it straightaway.

• If you (or your child) have been prescribed tenofovir granules, your doctor will advise you on how many scoopfuls of granules to take for each dose. Follow the manufacturer's instructions carefully to prepare each dose using the dosing scoop provided.Mix the granules into a soft food such as yoghurt or apple sauce. Mix each scoopful of granules with a tablespoon (15 ml) of food. Do not chew the granules/food mixture as you swallow it as it will taste bitter. Please note, the granules must not be mixed with liquids or drinks.

• Try to take tenofovir at the same time of day each day, as this will help you to remember to take it regularly. Take it with a meal or a snack.

• If you forget to take a dose, take it as soon as you remember, providing it is within the next 12 hours. If it is more than 12 hours later when you remember, leave out the missed dose but do remember to take your next dose when it is due. Do not take two doses together to make up for a forgotten dose.

Getting the most from your treatment

• Keep your regular appointments with your doctor so that your progress can be monitored. You will need to have some blood tests from time to time.

• It is important that you continue to take tenofovir regularly. Treatment for hepatitis B can be long-term. Continue to take tenofovir until you are advised otherwise by your doctor, even if you feel well.

• Most people with chronic hepatitis B will be advised to eat a normal healthy balanced diet. However, it is likely you will be advised not to drink alcohol. Alcohol will increase the risk and speed of you developing liver damage.

• Treatment with this medicine does not stop you from passing the infection on to others through sexual contact, sharing needles to inject drugs, or from mother to baby. A vaccine is available which protects against hepatitis B and can be offered to your sexual and household contacts who are at risk of being infected. Do not have sex with anyone (especially any sex without using a condom) until they have been fully immunised and have had their blood checked to see that the immunisation has worked.

• Tenofovir has been associated with a serious side-effect in some people who have taken it. This is known as lactic acidosis. It is a problem where there is too much lactic acid in the blood. The symptoms associated with it are listed in the next section 'Can tenofovir cause problems?'. If you develop any of the symptoms listed below, you must let your doctor know straightaway, as they can worsen, and may even become life-threatening.

• If you are having an operation or dental treatment, tell the person carrying out the treatment which medicines you are taking.

• If you buy any medicines, supplements or herbal remedies 'over the counter', check with a pharmacist that they are suitable to take with tenofovir and your other medicines.

Can tenofovir cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with tenofovir. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Your doctor will discuss with you the possibility of lactic acidosis occurring. Let your doctor know straightaway if you develop any of the following symptoms:

• Feeling sick (nausea) or being sick (vomiting), tummy pain, loss of appetite, loss of weight, feeling weak or dizzy, and fast or gasping breathing.

If you experience any other symptoms which you think may be due to the medicine, speak with your doctor or pharmacist for further advice.

How to store tenofovir

• Keep all medicines out of the reach and sight of children.

• Store in a cool, dry place, away from direct heat and light.

Important information about all medicines