Viramidine
Encyclopedia
Taribavirin is an antiviral drug
in Phase III human trials, but not yet approved for pharmaceutical use. It is a prodrug
of ribavirin
, active against a number of DNA
and RNA
virus
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. It is expected eventually to be the drug of choice for viral hepatitis syndromes in which ribavirin is active. These include hepatitis C
and perhaps also hepatitis B and yellow fever
.
. Valeant is testing the drug as a treatment for chronic hepatitis C.
. 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.
Antiviral drug
Antiviral drugs are a class of medication used specifically for treating viral infections. Like antibiotics for bacteria, specific antivirals are used for specific viruses...
in Phase III human trials, but not yet approved for pharmaceutical use. It is a prodrug
Prodrug
A prodrug is a pharmacological substance administered in an inactive form. Once administered, the prodrug is metabolised in vivo into an active metabolite, a process termed bioactivation. The rationale behind the use of a prodrug is generally for absorption, distribution, metabolism, and...
of ribavirin
Ribavirin
Ribavirin is an anti-viral drug indicated for severe RSV infection , hepatitis C infection and other viral infections. Ribavirin is a prodrug, which when metabolised resembles purine RNA nucleotides...
, active against a number of DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
and RNA
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
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. 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
Hepatitis C is an infectious disease primarily affecting the liver, caused by the hepatitis C virus . The infection is often asymptomatic, but chronic infection can lead to scarring of the liver and ultimately to cirrhosis, which is generally apparent after many years...
and perhaps also hepatitis B and yellow fever
Yellow fever
Yellow fever is an acute viral hemorrhagic disease. The virus is a 40 to 50 nm enveloped RNA virus with positive sense of the Flaviviridae family....
.
Uses
Taribavirin is as active against influenza 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 presently being developed by Valeant Pharmaceuticals InternationalValeant Pharmaceuticals International
Valeant Pharmaceuticals International, Inc. is a pharmaceutical company with activities spanning the drug discovery pipeline from target identification through clinical trials and commercialization. The focus of the company is on neurology, dermatology and infectious disease with several drugs in...
. 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 ribavirinRibavirin
Ribavirin is an anti-viral drug indicated for severe RSV infection , hepatitis C infection and other viral infections. Ribavirin is a prodrug, which when metabolised resembles purine RNA nucleotides...
. 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.