Tenofovir for HIV

jAbout tenofovir for HIV

Tenofovir is an antiviral medicine. It is prescribed for human immunodeficiency virus (HIV) infection. It slows the progress of HIV infection, but it is not a cure. HIV destroys cells in the body, called CD4 T cells. These cells are a type of white blood cell and are important because they are involved in protecting your body from infection. If left untreated, the HIV infection weakens your immune system so that your body cannot defend itself against bacteria, viruses and other germs. Tenofovir slows down the progress of HIV infection by reducing the amount of virus in your body. It does this by stopping the virus from copying (replicating) itself.

Tenofovir will be prescribed for you by a doctor who is a specialist. It belongs to a group of antiretroviral medicines known as nucleoside reverse transcriptase inhibitors (NRTIs). It is given alongside a number of other antiretroviral medicines, as part of a combination therapy. Taking three or more antiretroviral medicines at the same time is more effective than taking one alone. Taking a combination of different medicines also reduces the risk that the virus will become resistant to any individual medicine. Some brands of tenofovir tablet contain one or more other antiretroviral medicine (see the list in the table above) - these combination brands help to reduce the total number of tablets you need to take each day. Not all of the information in this leaflet applies to the combination brands, so please refer to the manufacturer's printed information leaflet from inside the pack for full details. It is vital to take your antiretroviral medicines exactly as prescribed to maintain success and to help to prevent the virus from becoming resistant to the medicines. These medicines are usually taken for life.

Tenofovir is also prescribed for another viral infection - see the separate medicine leaflet called Tenofovir for hepatitis B infection.

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 HIV

• 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. For adults, the usual dose is one 245 mg tablet daily. Children will be prescribed a lower-strength tablet depending upon their age and weight. For anyone who is unable to take tablets (such as young children) tenofovir is also available as granules. These are measured out using the dosing scoop provided, and then taken mixed into a soft food such as yoghurt, apple sauce or baby food. 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. Your doctor will advise you about how many scoopfuls of granules you (or your child) should take for each dose.

• 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.

• Take tenofovir tablets with a meal or a snack. (However, if you have been prescribed the combination brand Atripla®, these tablets should be taken when your stomach is empty, which means taking them one hour before any food or waiting until two hours afterwards.)

• Try to take tenofovir at the same time of day each day, as this will help you to remember to take it regularly.

• 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 regular blood tests to check how well your medicines are working.

• It is important that you continue to take tenofovir and your other antiretroviral treatment regularly. This will help to prevent the HIV from becoming resistant to the medicines you are taking. Even if you miss only a small number of doses, the virus can become resistant to treatment.

• If you develop an infection soon after you start the treatment, let your doctor know. As a result of taking tenofovir, your immune system may start fighting an infection which was present before you started the treatment, but which you may not have been aware of.

• Follow carefully any advice your doctor gives to you about making lifestyle changes to reduce any risk of damage to your heart and blood vessels. These can include stopping smoking, eating healthily and taking regular exercise.

• Some people taking antiretroviral medicines develop changes to the way body fat is distributed in the body. This can result in changes to body image. Your doctor will discuss the possibility of this with you.

• Although treatment with antiretroviral medicines may reduce the risk of you passing HIV to others through sexual contact, it does not stop it. It is important that you use condoms.

• It is not uncommon for people with HIV to feel low or even depressed, especially soon after the diagnosis has been made and treatment has been started. If you have any feelings of depression, or any distressing thoughts about harming yourself then you should speak with your doctor straightaway.

• 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.

• Some people who have taken antiretroviral medicines (particularly over a long time) have developed a condition called osteonecrosis. This is a bone disease where bone tissue dies because there is a reduced blood supply to it. It leads to joint pains and stiffness, and can cause difficulties in movement. If you notice any of these symptoms, speak with your doctor.

• 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. This is because some medicines interfere with antiretrovirals and can stop them from working properly.

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

• Treatment for HIV is usually lifelong. Continue to take tenofovir regularly for as long as your doctor tells you to, even if you feel well. This is to keep your immune system healthy.

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. You should, however, speak with your doctor if you develop any of the following side-effects. This is because some of the common side-effects of tenofovir are similar to the symptoms of lactic acidosis - a less common but more serious problem.

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 (abdominal) 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