Telbivudine

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Telbivudine is an antiviral drug used in the treatment of hepatitis B. It is a synthetic thymidine nucleoside analogue with potent and selective activity against the hepatitis B virus (HBV). Telbivudine is marketed under the brand name Tyzeka in the United States and Sebivo in other countries.

Mechanism of Action

Telbivudine works by inhibiting the DNA polymerase of the hepatitis B virus, which is essential for viral replication. By incorporating itself into the viral DNA, telbivudine causes premature chain termination, thereby preventing the virus from multiplying and spreading.

Pharmacokinetics

Telbivudine is administered orally and is well absorbed from the gastrointestinal tract. It reaches peak plasma concentrations within 1 to 4 hours after ingestion. The drug is primarily excreted unchanged in the urine, with a half-life of approximately 15 hours.

Clinical Use

Telbivudine is indicated for the treatment of chronic hepatitis B in patients with evidence of active viral replication and either evidence of persistent elevations in serum alanine aminotransferase (ALT) or histologically active disease. It is particularly effective in patients who are nucleoside analogue-naive.

Side Effects

Common side effects of telbivudine include:

• Fatigue
• Headache
• Nausea
• Diarrhea
• Myopathy
• Peripheral neuropathy

Resistance

Resistance to telbivudine can develop, particularly with long-term use. The most common mutation associated with resistance is the M204I mutation in the HBV polymerase gene. Cross-resistance with other nucleoside analogues, such as lamivudine and entecavir, can also occur.

Contraindications

Telbivudine is contraindicated in patients with a known hypersensitivity to the drug or any of its components. Caution is advised in patients with renal impairment, as dose adjustments may be necessary.

Pregnancy and Lactation

Telbivudine is classified as a pregnancy category B drug. It should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. It is not known whether telbivudine is excreted in human milk; therefore, caution should be exercised when administered to nursing mothers.

See Also

• Hepatitis B
• Antiviral drug
• Nucleoside analogue
• Lamivudine
• Entecavir