telbivudine

Action and Spectrum

Actions and Spectrum: 

Action: 

Inhibition of HBV Reverse Transcriptase: telbivudine exerts its primary action by inhibiting the reverse transcriptase enzyme of the hepatitis B virus. By inhibiting this enzyme, telbivudine hinders the conversion of the viral RNA into DNA, thus preventing the replication of the virus. 

Spectrum: telbivudine has a relatively narrow spectrum of activity, primarily targeting the hepatitis B virus (HBV). It is not effective against other types of viruses, including hepatitis C virus (HCV) or human immunodeficiency virus (HIV). Therefore, its clinical use is limited to treating chronic hepatitis B infections. 

Drug Interaction

Adverse Reaction

Frequency not defined  

Trouble sleeping 

Dizziness 

Back pain 

Diarrhea 

Cough 

Headache 

Belly pain 

Black Box Warning

Black Box Warning:  

The condition of individuals with hepatitis B deteriorated when discontinuing the use of telbivudine tablets in some cases.  

telbivudine has been associated with the risk of lactic acidosis, myopathy (muscle disorders), and neuropathy (nerve disorders). 

Contraindication / Caution

Contraindication/Caution:  

Hypersensitivity: Patients with a known hypersensitivity or allergy to telbivudine or any of its components should not use this medication. 

Severe Hepatic Impairment: telbivudine is metabolized by the liver, and its safety and effectiveness in patients with severe liver impairment have not been established. It should be used cautiously or avoided in individuals with severe liver dysfunction. 

Pregnancy: The administration of telbivudine during pregnancy is typically discouraged unless the advantages surpass the potential risks to the developing fetus. Discussing the risks and benefits with a healthcare provider if pregnancy is a consideration is essential. 

Pregnancy / Lactation

Pregnancy warnings:     

Pregnancy category: AU TGA pregnancy category: B1
US FDA pregnancy category: B 

Lactation: Excreted into human milk is unknown 

Pregnancy Categories:         

Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester. 

Category B: There were a lack of studies on pregnant women and no evidence of risk to the fetus in animal experiments.   

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.   

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: There is no data available for the drug under this category  

Pharmacology

Pharmacology:  

telbivudine is an antiviral medication used to treat chronic hepatitis B virus (HBV) infection. 

Pharmacodynamics:  

telbivudine exerts its pharmacological effects primarily through its action on the hepatitis B virus. It is a nucleoside analogue, which means it mimics one of the building blocks of DNA, specifically thymidine. 

telbivudine is incorporated into the growing DNA chain during viral replication, causing premature termination of the DNA strand. This disruption in viral DNA synthesis ultimately inhibits the replication of the hepatitis B virus.   

Pharmacokinetics: 

Absorption 

telbivudine is well-absorbed after oral administration and reaches peak plasma concentrations within 1-3 hours. 

Distribution 

It has a low binding to plasma proteins (approximately 25%). 

Metabolism 

telbivudine is primarily metabolized in the liver through phosphorylation to its active form. 

Excretion and Elimination 

The primary route of excretion for the drug and its metabolites is through urine. The half-life of telbivudine is about 40-49 hours in patients with chronic hepatitis B. 

Adminstartion

Administration:  

telbivudine is typically taken orally as a tablet or solution. It can be taken with or without food, but it’s essential to follow the specific instructions provided by the healthcare provider or included in the medication’s package insert. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: telbivudine 

Why do we use telbivudine?  

Treatment of Chronic Hepatitis B: telbivudine is prescribed to individuals with chronic hepatitis B infection to reduce the viral load in the body. 

Viral Suppression: telbivudine helps to suppress the replication of the hepatitis B virus, leading to a decrease in viral DNA levels in the blood. This can improve liver function and reduce inflammation. 

Prevention of Liver Damage: By reducing the viral load and inflammation in the liver, telbivudine can help prevent or slow down the development of liver fibrosis (scarring) and cirrhosis.