What is Zeffix?
Zeffix is a medicine that contains the active substance lamivudine. It is available as yellow capsule-shaped tablets (100 mg) and as an oral solution (5 mg / ml).
What is Zeffix used for?
Zeffix is used for the treatment of chronic hepatitis B (a long-term liver infection caused by the hepatitis B virus) in adults. It is used in patients with:
- compensated liver disease (the liver is damaged but functioning normally), which also shows signs that the virus continues to multiply and shows signs of liver damage (increased levels of the liver enzyme alanine aminotransferase [ALT] and signs of damage when the tissue hepatic is examined under a microscope);
- decompensated liver disease (the liver does not function normally).
The medicine can only be obtained with a prescription.
How is Zeffix used?
Zeffix therapy should be started by a doctor who has experience in the treatment of chronic hepatitis B virus infection.
The recommended dose of Zeffix is 100 mg once a day. The medicine can be taken with or without food. In patients with kidney problems it is necessary to reduce the dose. Doses below 100 mg should be administered with the oral solution. The duration of treatment depends on the patient's condition and the response to therapy. For further information, please refer to the summary of product characteristics (also included with the EPAR).
How does Zeffix work?
The active substance in Zeffix, lamivudine, is an antiviral agent that belongs to the class of "nucleoside analogues". Lamivudine interferes with the action of a viral enzyme, DNA polymerase, which is involved in the formation of virus DNA. Lamivudine stops the production of DNA by the virus, thus preventing it from multiplying and spreading.
What studies have been carried out on Zeffix?
Zeffix has been studied in five main studies involving a total of 1, 083 adults with compensated liver disease due to chronic hepatitis B. In three studies, Zeffix was compared with placebo (a dummy treatment), in one of which "HBeAg negative" patients were particularly observed. These are patients with the mutated hepatitis B virus, which causes a more difficult form of chronic hepatitis B to treat. In the other two studies Zeffix taken alone was compared with alpha-interferon (another treatment used for chronic hepatitis B) taken alone and with the combination of Zeffix and alpha-interferon. In a further analysis, patients were compared with and without the "YMDD mutation" (a change in the DNA of the hepatitis B virus often found after lamivudine treatment).
Information on the use of Zeffix in patients with decompensated liver disease was also presented.
There have been several measures of effectiveness in the studies. Among these was the observation of how liver damage developed after a year of treatment using a liver biopsy (removal of a small sample of liver tissue to be examined under a microscope), as well as the measurement of other signs of the disease such as levels of ALT or DNA of the hepatitis B virus circulating in the blood.
What benefit has Zeffix shown during the studies?
In patients with compensated liver disease, Zeffix was more effective than placebo in slowing the progression of liver disease. In about half of the patients who took Zeffix there was an improvement in the liver damage found in the biopsy, compared to about a quarter of the patients who took the placebo. Zeffix was as effective as alpha-interferon. In further analysis it was observed that patients with the YMDD mutation did not respond as well to treatment with Zeffix as those without the mutation.
In patients with decompensated liver disease, Zeffix also reduced the levels of hepatitis B virus and ALT DNA.
What is the risk associated with Zeffix?
The most common side effect of Zeffix (seen in more than 1 patient in 10) is increased 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.
Why has Zeffix been approved?
The Committee for Medicinal Products for Human Use (CHMP) considered that the benefits of Zeffix are greater than its risks in the treatment of chronic hepatitis B in adults with compensated liver disease with evidence of active viral replication, consistently high levels of ALT and histological evidence of inflammation and / or active hepatic fibrosis, and in adults with decompensated liver disease. The Committee recommended that Zeffix be granted marketing authorization.
Zeffix was initially authorized in "exceptional circumstances", because at the time the authorization was granted, for scientific reasons, only limited information was available. As the company provided the additional information requested, the condition referring to "exceptional circumstances" was removed on 18 May 2001.
More information on Zeffix:
On 29 July 1999, the European Commission issued a marketing authorization for Zeffix to Glaxo Group Ltd, valid throughout the European Union. This authorization was renewed on July 29, 2004 and July 29, 2009.
For the full EPAR for Zeffix, click here.
Last update of this summary: 07-2009.
