Zeffix is a medicine that contains the active substance lamivudine. It is available as yellow, capsule-shaped tablets (100 mg) and an oral solution (5 mg/ml).
|Table of Contents|
|What is it used for?|
|How is it used?|
|How does it work?|
|How has it been studied?|
|What benefits has it shown during the studies?|
|What is the risk associated?|
|Why has it been approved?|
Zeffix is used to treat adults (aged 18 years or over) who have chronic (long-term) hepatitis B (a disease of the liver due to infection with the hepatitis B virus). It is used in patients with:
- compensated liver disease (when the liver is damaged but works normally), who also show signs that the virus is still multiplying and have signs of liver damage (raised levels of the liver enzyme alanine aminotransferase [ALT] and signs of damage when liver tissue is examined under a microscope). Because the hepatitis B virus can become resistant to Zeffix, the doctor should only consider prescribing Zeffix if other treatments that are less likely to lead to resistance cannot be used;
- decompensated liver disease (when the liver does not work normally). To reduce the risk of resistance, Zeffix must be used in combination with another anti-hepatitis B medicine that does not cause resistance in the same way as Zeffix.
The medicine can only be obtained with a prescription.
Treatment with Zeffix should be started by a doctor who has experience in the management of chronic hepatitis B.
The recommended dose of Zeffix is 100 mg once a day. The dose needs to be lower in patients who have problems with their kidneys. Doses lower than 100 mg need to be given using the oral solution. The duration of treatment depends on the patient?s condition and response to treatment.
If the hepatitis B virus can still be found in the blood after six months of treatment, the doctor should consider changing treatment to reduce the risk of resistance. Patients infected with virus that has the ?YMDD mutation? (a change in the virus?s DNA that is often found after treatment with lamivudine) should take Zeffix in combination with another medicine against hepatitis B. For more information, see the summary of product characteristics (also part of the EPAR).
The active substance in Zeffix, lamivudine, is an antiviral agent that belongs to the class ?nucleoside analogues?. Lamivudine interferes with the action of a viral enzyme called DNA polymerase, which is involved in the formation of viral DNA. Lamivudine stops the virus making DNA and prevents it from multiplying and spreading.
Zeffix has been studied in five main studies involving a total of 1,083 adults with compensated liver disease due to chronic hepatitis B. Three studies compared Zeffix with placebo (a dummy treatment), one of which looked particularly at ?HBeAg-negative? patients. These are patients infected with hepatitis B virus that has mutated (changed), leading to a form of chronic hepatitis B that is more difficult to treat. The other two studies compared Zeffix taken on its own with alfa-interferon (another treatment used in chronic hepatitis B) on its own and with the combination of Zeffix and alfa-interferon. A further analysis was carried out comparing patients with and without the YMDD mutation.
In addition, information was presented on the use of Zeffix in patients with decompensated liver disease.
There were several measures of effectiveness in the studies. These included looking at how the liver damage had evolved after a year of treatment using a liver biopsy (when a small sample of liver tissue is taken and examined under a microscope), as well as measuring other signs of the disease such as the levels of ALT or of hepatitis B virus DNA circulating in the blood.
In patients with compensated liver disease, Zeffix was more effective than placebo in slowing down the progression of liver disease. About half of the patients taking Zeffix had an improvement in liver damage assessed in a biopsy, compared with about a quarter of the patients who took placebo. Zeffix was as effective as alfa-interferon. The further analysis showed that patients with the YMDD mutation do not respond as well to treatment with Zeffix as those without the mutation.
In patients with decompensated liver disease, Zeffix also reduced levels of hepatitis B virus DNA and ALT.
The most common side effect with Zeffix (seen in more than 1 patient in 10) is raised ALT levels. For the full list of all side effects reported with Zeffix, see the package leaflet.
Zeffix should not be used in people who may be hypersensitive (allergic) to lamivudine or any of the other ingredients.