Lamivudine for hepatitis B infection Zeffix

Last updated by Peer reviewed by Sid Dajani
Last updated Meets Patient’s editorial guidelines

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Lamivudine is an antiretroviral medicine. You have been prescribed it for chronic hepatitis B infection.

Take one (100 mg) tablet daily. You can take your doses either before or after meals.

Each time you collect a new supply of tablets from your pharmacy, make sure they look to be the same as you have had before. If you are unsure, ask your pharmacist to check it out for you.

Type of medicineA nucleoside reverse transcriptase inhibitor antiretroviral medicine
Used forHepatitis B in adults
Also calledZeffix®
Available asTablets

Hepatitis means inflammation of the liver. Some viruses can cause hepatitis (although there are several other causes too). Hepatitis B is a virus which is carried in your bloodstream to your liver. It can affect and damage your liver. Following an infection with hepatitis B, a few people develop a persistent infection called chronic hepatitis B.

People with chronic hepatitis B usually need treatment to stop or to reduce the activity of the virus. This limits damage to the liver, which is a complication of the infection. One of the types of treatment currently given is an antiviral medicine. Antiviral medicines like lamivudine 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.

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

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 lamivudine it is important that your doctor knows:

  • If you are pregnant or breastfeeding.
  • If you have problems with the way your kidneys work.
  • 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.
  • Before you start the treatment, read the manufacturer's printed information leaflet from inside your pack. It will give you more information about lamivudine, and it will also provide you with a full list of the side-effects which you could experience from taking it.
  • The usual dose is one 100 mg tablet daily. Take lamivudine exactly as your doctor tells you to - your dose will be printed on the label of the pack to remind you about what the doctor said to you.
  • It is recommended that you swallow the tablet whole (not chewed or crushed). Take it with a drink of water.
  • Try to take lamivudine at the same time each day, as this will help you to remember to take it regularly. You can take the tablet either with or without food.
  • If you forget to take a dose, take it as soon as you remember. If you do not remember until the following day, leave out the missed dose. Do not take two doses together to make up for a forgotten dose.
  • Keep your regular appointments with your doctor. This is 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 lamivudine regularly. Treatment for hepatitis B can be long-term. Continue to take the tablets, even if you feel well. This is to keep your liver healthy.
  • Treatment with lamivudine 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.
  • Each time you collect a new supply of these tablets from your pharmacy, make sure they look to be the same as you have had before. This is because there is another brand of lamivudine available which is used to treat a different type of infection. If you are unsure about your prescription in any way, ask your pharmacist to check it out for you.
  • Lamivudine has been associated with a serious side-effect in some people who have taken it for another type of infection. 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 lamivudine cause problems?'. Although this has occurred in only a very few people who have taken it for hepatitis B, you must let your doctor know straightaway if you develop any of the symptoms listed below.
  • If you buy any medicines, supplements or herbal remedies 'over the counter', check with a pharmacist that they are suitable to take with lamivudine and your other medicines.
  • If you are having an operation or dental treatment, tell the person carrying out the treatment which medicines you are taking.

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 lamivudine. 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.

Common lamivudine side-effects
What can I do if I experience this?
HeadacheDrink plenty of water and ask a pharmacist to recommend a suitable painkiller. If the headaches continue, let your doctor know
Feeling tiredDo not drive and do not use tools or machines while affected. If this continues, speak with your doctor
Tummy (abdominal) discomfort, feeling sick (nausea) or being sick (vomiting)Stick to simple meals - avoid rich or spicy food. If it continues, speak with your doctor
DiarrhoeaDrink plenty of water
Itchy rash, muscle cramps and pains, respiratory tract infections, sore throatIf any becomes troublesome, speak with your doctor
Changes to some blood testsYour doctor will check for these

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 tablets, speak with your doctor or pharmacist for further advice.

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

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital at once. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

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