Taribavirin (

rINN Rinn is a municipality in the district of Innsbruck-Land in the Austrian state of Tyrol located 6 km southeast of Innsbruck. The village was mentioned in documents as “Runne” in 1250 for the first time. Population Climate Climate typ ...

; also known as viramidine, codenamed ICN 3142) is an

antiviral drug Antiviral drugs are a class of medication used for treating viral infections. Most antivirals target specific viruses, while a broad-spectrum antiviral is effective against a wide range of viruses. Antiviral drugs are a class of antimicrobials ...

in Phase III human trials, but not yet approved for pharmaceutical use. It is a

prodrug A prodrug is a pharmacologically inactive 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 ...

ribavirin Ribavirin, also known as tribavirin, is an antiviral medication used to treat illness caused by respiratory syncytial virus (RSV) and hepatitis C virus (HCV) infections, as well as some viral hemorrhagic fevers. For HCV, it is used in combi ...

, active against a number of

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

and

RNA Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...

virus A virus is a submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are ...

es. Taribavirin has better liver-targeting than ribavirin, and has a shorter life in the body due to less penetration and storage in

red blood cells Red blood cells (RBCs), referred to as erythrocytes (, with -''cyte'' translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells, erythroid cells, and rarely haematids, are the most common type of blood cel ...

. It is expected eventually to be the drug of choice for viral hepatitis syndromes in which ribavirin is active. These include

hepatitis C Hepatitis C is an infectious disease caused by the hepatitis C virus (HCV) that primarily affects the liver; it is a type of viral hepatitis. During the initial infection period, people often have mild or no symptoms. Early symptoms can include ...

and perhaps also

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. ...

and yellow fever.

Uses

Taribavirin is as active against

influenza Influenza, commonly known as the flu, is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These sympto ...

as ribavirin in animal models, with slightly less toxicity, so it may also eventually replace ribavirin as an anti-influenza agent.

History

Taribavirin was first reported in 1973 by J. T. Witkowski et al., then working at ICN Pharmaceuticals, in an attempt to find a more active derivative of ribavirin. Taribavirin is being developed by

Valeant Pharmaceuticals International Bausch Health Companies Inc. is a global, diversified American-Canadian pharmaceutical company. Its global corporate headquarters are located in Laval, Quebec, Canada, and its U.S. headquarters are in Bridgewater, New Jersey. It develops, manufa ...

. Valeant is testing the drug as a treatment for chronic hepatitis C.

Pharmacology

Note on formulas: The carboxamidine group of this molecule is somewhat basic, and therefore this drug is also known and administered as the hydrochloride salt (with a corresponding HCl chemical formula and different ChemID / PubChem number). At physiologic pH, the positive charge on the molecule from partial protonation of the carboximide group contributes to the relative slowness with which the drug crosses cell membranes (such as in red blood cells) until it has been metabolized into

. In the liver, however, the transformation from carboxamidine to carboxamide happens on first-pass metabolism and contributes to the higher levels of ribavirin found in liver cells and bile when viramidine is administered.

Notes

References

# # # # #

{{RNA antivirals Anti–RNA virus drugs Prodrugs Triazoles Amidines Experimental antiviral drugs