Hepsera - adefovir dipivoxil
What is Hepsera?
Hepsera is a medicine that contains the active substance adefovir dipivoxil. It is available as white round tablets (10 mg).
What is Hepsera used for?
Hepsera is used to treat chronic hepatitis B (long-term infectious liver disease due to a hepatitis B virus infection) in adult patients with:
- compensated liver disease (in which the liver functions normally, despite being damaged) with signs of active viral replication and signs of liver damage (indicated by elevated levels of the liver enzyme alanine aminotranferase (ALT) and detected by examination of liver tissues at microscope);
- decompensated liver disease (in which the liver is damaged and does not function normally).
The medicine can only be obtained with a prescription.
How is Hepsera used?
Treatment with Hepsera should be started by a doctor with experience in the treatment of chronic hepatitis B. The recommended dose is 10 mg once a day, to be taken with or without food. The duration of treatment varies depending on the patient's condition. and response to treatment, which should be checked every six months. Patients with kidney problems need to decrease the frequency of taking Hepsera.
Hepsera is not recommended in patients with severe kidney disease or on dialysis (blood purification method); for these patients it should only be used if its potential benefits outweigh its potential risks.
Patients whose disease is caused by a virus resistant (unresponsive) to lamivudine (another antiviral medicine) Hepsera should not be given alone, to reduce the risk of developing resistance to Hepsera. These patients should be given Hepsera in combination with lamivudine or given another treatment. A change of therapy should also be made if virus levels remain high after one year of treatment with Hepsera alone.
For more information, please refer to the Summary of Product Characteristics included in the EPAR.
How does Hepsera work?
The active substance in Hepsera, adefovir dipivoxil, is a 'prodrug' which is converted into adefovir in the body. Adefovir is an antiviral belonging to the class called 'nucleoside analogues'. Adefovir interferes with the action of a viral enzyme called DNA polymerase, which is involved in the formation of the virus' DNA. Adefovir stops the virus from making DNA, thus preventing it from multiplying and spreading.
How has Hepsera been studied?
Hepsera has been studied in two main studies where it was compared with placebo (a dummy treatment). The first study involved 511 "HBeAg-positive" patients (infected with the "common type hepatitis B virus), while the second involved 184" HBeAg-negative "patients (infected with a mutated virus, which caused a form of chronic hepatitis B more difficult to cure). In both studies the efficacy was measured by evaluating the evolution of liver damage after 48 weeks of treatment.
What benefit has Hepsera shown during the studies?
Hepsera was more effective than placebo in slowing the progression of liver disease. Of the Hepsera-treated patients, 53% of the HBeAg-positive and 64% of the HBeAg-negative patients had improvement in biopsy-detected liver injury versus 25% and 33% of the placebo-treated patients, respectively.
What is the risk associated with Hepsera?
The most common side effects associated with Hepsera treatment (seen in more than 1 in 10 patients) are an increase in creatinine (indicating kidney problems) and asthenia (weakness). For the full list of side effects reported with Hepsera, see the Package Leaflet.
Hepsera must not be used in patients who may be hypersensitive (allergic) to adefovir dipivoxil or any of the other ingredients.
Why has Hepsera been approved?
The Committee for Medicinal Products for Human Use (CHMP) decided that Hepsera's benefits are greater than its risks for the treatment of chronic hepatitis B adult patients with compensated liver disease and signs of active viral replication, persistently elevated serum ALT and histological evidence of active inflammation and liver fibrosis as well as in adult patients with decompensated liver disease. The Committee recommended the granting of a marketing authorization for Hepsera.
Other information about Hepsera:
On 6 March 2003, the European Commission granted Gilead Sciences International Limited a "Marketing Authorization" for Hepsera, valid throughout the European Union. The "Marketing Authorization" was renewed on 6 March 2008.
For the full version of Hepsera's EPAR click here.
Last update of this summary: 01-2009.
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