Telbivudine

Telbivudine is a prescription drug used for the treatment of chronic hepatitis B in adults. It prevents the hepatitis virus from replicating in patients with active disease. The Food and Drug Administration approved telbivudine on September 25, 2000. Telbivudine is co-marketed as Tyzeka (in the United States) and Sebivo (in Europe) by Idenix Pharmaceuticals and Novartis.

This is a transmission electron micrograph of hepatitis B viruses Source: Wikimedia Commons

Uses

Telbivudine is an antiviral used to treat adults with chronic hepatitis B. It is used in people whose blood shows that the virus is replicating, and who have persistent signs of liver damage (elevated blood levels of aminotransferase enzymes) or signs of active disease.

How Telbivudine is Taken

Telbivudine is available in 600 mg tablets. The recommended dose is one tablet taken once a day.

How Telbivudine Works

The hepatitis B virus uses and enzyme called reverse transcriptase to make DNA and replicate. Telbivudine is an antiretroviral drug. It binds to reverse transcriptase and is incorporated into the DNA strand that the enzyme is making. This process stops the enzyme from extending the length of the DNA strand, and thereby prevents the viruses from replicating.

How the Body Affects Telbivudine

Telbivudine reaches a maximum concentration in the blood between one and four hours after dosing. It is not metabolized and is primarily excreted unchanged in the urine. Because telbivudine is largely excreted by the kidneys, people who have moderate to severe kidney impairment sometimes need to adjust the dose.

Side Effects

In clinical studies, telbivudine was well-tolerated. Most side effects were mild or moderate in severity and were not necessarily caused by the drug.

Some of the more common side effects of telbivudine include the following:

• chills and shivering
• cough
• diarrhea
• fever
• headache
• sore throat
• joint, muscle, or stomach pain
• loss of appetite
• nausea and vomiting
• runny nose
• sweating
• trouble sleeping

Risks and Precautions

• Severe worsening of hepatitis B symptoms have been reported in patients who discontinued anti-hepatitis B therapy.

• Some cases of muscle injury (aches, weakness, and biochemical markers of cell damage) have been reported with telbivudine use several weeks to months after starting therapy.
  • Telbivudine is eliminated primarily by the kidneys. Therefore, doses are often adjusted in people with kidney impairment.

• Telbivudine does not prevent the transmission of the virus from one person to another.

Drug Interactions

Drugs that reduce kidney function could affect the amount of telbivudine excreted in the urine. If this happens, the concentration of telbivudine in the blood may increase.

Alternatives

Other drugs used to treat hepatitis B include lamivudine (Pivir) and adefovir (Hepsera). These drugs also inhibit replication of the hepatitis B virus.

Clinical Trials

The effectiveness of telbivudine was evaluated in the 007 GLOBE study, which was a clinical trial of over 1,300 patients with chronic hepatitis B who had never been treated. The 007 GLOBE study compared the effectiveness of telbivudine (600 mg) once daily to lamivudine (100 mg) once daily for a treatment period of up to 104 weeks. ^[1]

In the study, the patients were divided into two groups: those who had antibodies against the virus in their blood and those who did not.

Of patients with the antibodies, 75% and 67% responded to treatment with telbivudine and lamivudine, respectively. Of patients who did not have the antibodies, 75% and 77% responded to treatment with telbivudine or lamivudine, respectively.

References

1. ↑ CenterWatch Web site. Newly Approved Drug Therapies (936): Tyzeka (telbivudine), Idenix Pharma

External Links

Tyzeka Home Page

FDA Approves New Treatment for Chronic Hepatitis B in Adults

FDA: Patient Information Sheet