Adefovir for hepatitis B (Hepsera)

The usual dose is one tablet daily.

It is important to take adefovir regularly every day, preferably at the same time each day.

Common side-effects are feeling weak, feeling sick, diarrhoea, and headache.

About adefovir

Type of medicine An antiviral medicine
Used for Chronic hepatitis B infection in adults
Also called Adefovir dipivoxil, Hepsera®
Available as Tablets

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. Treatment for chronic hepatitis B may continue for several years and may include a combination of antiviral medicines.

Adefovir reduces the amount of the virus in your body and this helps to reduce the damage to your liver. Adefovir will be prescribed for you by a doctor who is a specialist.

Before taking adefovir

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

  • If you are pregnant or breast-feeding.
  • If you have a problem with the way your kidneys work.
  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
  • If you have ever had an allergic reaction to a medicine.

How to take adefovir

  • Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about adefovir and a full list of side-effects which you may experience from taking it.
  • Take adefovir exactly as your doctor has told you to. The usual dose is one tablet daily. You can take the tablets before or after meals.
  • Try to take your doses at the same time of day each day, as this will help you to remember to take them.
  • If you vomit within 1 hour of taking a tablet, you should take a second tablet. This is because your body will not have absorbed a sufficient amount of the medicine. If however you are sick and it is more than 1 hour after taking a tablet, you do not need to take a second dose as your body will have already absorbed the full dose.
  • If you forget to take a dose, take it as soon as you remember. If you do not remember until the following day, skip the missed dose. 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 are likely to need regular blood tests to check how well this medicine is working for you, and also to see how well your liver and kidneys are working.
  • It is important that you continue to take adefovir regularly. Treatment for hepatitis B can be long-term. You should continue to take the tablets, even if you feel well.
  • Medicines similar to adefovir have been associated with a serious side-effect in a few people. 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 below the table in the next section 'Can adefovir cause problems?'. You must let your doctor know straightaway, if you develop any of the symptoms listed.
  • You must avoid getting pregnant while you are taking adefovir. Make sure you have discussed with your doctor which types of contraception are suitable for you.
  • If you buy any medicines, check with your pharmacist that they are suitable to take with this medicine.
  • If you are having an operation or dental treatment, tell the person carrying out the treatment which medicines you are taking.
  • 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.
  • 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.

Can adefovir cause problems?

Along with their useful effects, all medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Common adefovir side-effects What can I do if I experience this?
Feeling tired or weak Do not drive or use tools or machines until you feel better. If this continues, speak with your doctor
Feeling or being sick, indigestion, wind, abdominal pain Stick to simple meals - avoid rich or spicy food. If it continues, speak with your doctor
Diarrhoea Drink plenty of water to replace lost fluids
Headache Ask your doctor or pharmacist to recommend a suitable painkiller
Itchy rash If troublesome, speak with your doctor
Changes to some blood tests Your doctor will check for this

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

  • Feeling or being sick, abdominal pain, loss of appetite, loss of weight, fast or gasping breathing.

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

How to store adefovir

  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light.