Do not take Zeffix:
- if you are allergic (hypersensitive) tolamivudine or to any of the other ingredients of Zeffix.
If you are not sure please consult your doctor.
Take special care with Zeffix
Zeffix reduces the amount of hepatitis B virus in your body, and keeps the liver disease under control, therefore reducing health problems relating to your liver in the future. For effective treatment you will need to take Zeffix every day. Patients respond to the treatment differently, therefore it is not known for how long you will have to take this medicine.
Your doctor will be checking your response to treatment by taking regular blood samples. The results of these tests will help your doctor to decide when your treatment with Zeffix can be stopped.
Before treatment with Zeffix you should have discussed any additional medical problems that you have with your doctor. If you have kidney disease the dose of this medicine may have to be reduced, as it is your kidneys that are mainly responsible for getting rid of the medicine from your body. Zeffix is also available as an oral solution. This means that your doctor can prescribe a lower dose for you if necessary.
Do not stop taking Zeffix without instruction from your doctor, as there is a small risk of your hepatitis getting worse. When you stop taking Zeffix your doctor will monitor you for at least the following four months to check for any problems. This will mean taking blood samples to check for any abnormal liver enzymes, indicating liver damage.
The active substance in Zeffix is lamivudine. If you are already taking this medicinal product for HIV infection, your doctor will continue to treat you with the higher dose, usually 150 mg twice a day, as the lower dose of 100 mg lamivudine is insufficient to treat HIV infection.
Because your medicine helps to control your hepatitis B and it is not yet known whether it will cure it, you are still at risk of transmitting this virus to others through sexual contact or by blood transfer, and you should use appropriate precautions to prevent this. There is an effective vaccine available to protect those at risk from becoming infected with hepatitis B virus.
The class of medicines to which Zeffix belongs (NRTIs) can cause a condition called lactic acidosis (build up of lactic acid in the body), together with an enlarged liver. Lactic acidosis, if it occurs, usually develops after a few months of treatment. Deep, rapid breathing, drowsiness, and non specific symptoms such as nausea, vomiting and stomach pain, might indicate the development of lactic acidosis. This rare, but serious side effect occurs more often in women, particularly if very overweight. As you have liver disease you may also be more at risk of getting this condition. While you are being treated with Zeffix your doctor will monitor you closely for any signs that you may be developing lactic acidosis.
Taking other medicines
Some medicines may affect the action of Zeffix. Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines, including medicines obtained without a prescription.
Zeffix should not be taken with:
- zalcitabine or lamivudine (used to treat HIV infection)
- emtricitabine (used to treat HIV or hepatitis B infection).
Taking Zeffix with food and drink
Zeffix can be taken with food or on an empty stomach.
Ask your doctor or pharmacist for advice before taking any medicine.
Tell your doctor if you are pregnant, or are planning to become pregnant, or if you are breast-feeding. Your doctor will advise whether you should continue to take Zeffix while you are pregnant. Do not stop treatment with Zeffix without your doctor?s advice.
The ingredients in Zeffix can pass into breast-milk. If you are breast-feeding, you must check with your doctor before you take Zeffix.
Driving and using machines
No studies on the effect of Zeffix on the ability to drive and use machines have been performed.