Adefovir is a prescription medicine used to treat (chronic) infections with hepatitis B virus. A prodrug form of adefovir was previously called bis-POM PMEA, with trade names Preveon and Hepsera. It is an orally administered nucleotide analog

reverse-transcriptase inhibitor Reverse-transcriptase inhibitors (RTIs) are a class of antiretroviral drugs used to treat HIV infection or AIDS, and in some cases hepatitis B. RTIs Enzyme inhibition, inhibit activity of reverse transcriptase, a viral DNA polymerase that is requi ...

(ntRTI). It can be formulated as the pivoxil

prodrug A prodrug is a medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be used to improve how the drug ...

adefovir dipivoxil.

Uses

It is used for treatment of

hepatitis B Hepatitis B is an infectious disease caused by the ''Hepatitis B virus'' (HBV) that affects the liver; it is a type of viral hepatitis. It can cause both acute and chronic infection. Many people have no symptoms during an initial infection. Fo ...

. Trials of adefovir in patients with

HIV The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune ...

have not shown any clear benefits.

History

Adefovir was invented in the Institute of Organic Chemistry and Biochemistry,

Academy of Sciences of the Czech Republic The Czech Academy of Sciences (abbr. CAS, cs, Akademie věd České republiky, abbr. AV ČR) was established in 1992 by the Czech National Council as the Czech successor of the former Czechoslovak Academy of Sciences and its tradition goes back ...

Antonín Holý Antonín Holý (1 September 1936 – 16 July 2012) was a pioneering Czech scientist. He specialised in the field of chemistry and cooperated on the development of important antiretroviral drugs used in the treatment of HIV and hepatitis B. He ...

, and the drug was developed by

Gilead Sciences Gilead Sciences, Inc. () is an American biopharmaceutical company headquartered in Foster City, California, that focuses on researching and developing antiviral drugs used in the treatment of HIV/AIDS, hepatitis B, hepatitis C, influenza, and CO ...

for HIV with the brand name Preveon. However, in November 1999, an expert panel advised the U.S.

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...

(FDA) not to approve the drug due to concerns about the severity and frequency of kidney toxicity when dosed at 60 or 120 mg. The FDA followed that advice, refusing to approve adefovir as a treatment for HIV. Gilead Sciences discontinued its development for HIV treatment in December 1999, but continued to develop the drug for hepatitis B (HBV), where it is effective with a much lower dose of 10 mg. FDA approval for use in the treatment of hepatitis B was granted on September 20, 2002, and adefovir is sold for this indication under the brand name Hepsera. Adefovir became an approved treatment for HBV in the European Union in March 2003.

Mechanism of action

Adefovir works by blocking

reverse transcriptase A reverse transcriptase (RT) is an enzyme used to generate complementary DNA (cDNA) from an RNA template, a process termed reverse transcription. Reverse transcriptases are used by viruses such as HIV and hepatitis B to replicate their genomes, ...

, an enzyme crucial for the HBV to reproduce in the body. It is approved for the treatment of chronic hepatitis B in adults with evidence of active viral replication and either evidence of persistent elevations in serum

aminotransferase Transaminases or aminotransferases are enzymes that catalyze a transamination reaction between an amino acid and an α-keto acid. They are important in the synthesis of amino acids, which form proteins. Function and mechanism An amino acid co ...

s (primarily ALT) or histologically active disease. The main benefit of adefovir over

lamivudine Lamivudine, commonly called 3TC, is an antiretroviral medication used to prevent and treat HIV/AIDS. It is also used to treat chronic hepatitis B when other options are not possible. It is effective against both HIV-1 and HIV-2. It is typicall ...

(the first NRTI approved for the treatment of HBV) is that it takes a much longer period of time for the virus to develop resistance to it. Adefovir dipivoxil contains two

pivaloyloxymethyl Pivaloyloxymethyl (POM, pivoxil, pivoxyl) is a protecting group used in organic synthesis.''Protective Groups in Organic Synthesis'', 3rd Edition, Theodora M. Greene and Peter G. M. Wuts, The POM radical has the formula (CH3)3C-CO-O-CH2. The PO ...

units, making it a

form of adefovir.

References

External links

* - Adefovir dipivoxil {{Antivirals Gilead Sciences Reverse transcriptase inhibitors Purines Phosphonic acids