Spectra influenza viruses

Scholar EM, Pratt WB (2000) Chemodrerapy of viral infecdons, I drugs used to treat influenza virus infecdons, herpes virus infecdons, and drugs widr broad-spectrum antiviral acdvity. hr The Andmicrobial Drugs, pp 491—549. Oxford Oxford University Press. 

Ribavirin inhibits (he replication of a very wide variety of RNA and DNA viruses, including orthomyxoviruses, paramyxoviruses, arenaviruses, bunyavirusc,s, herpesviruses, adenoviruses, poxvirus, vaccinia, influenza virus, parainfluenza virus, and rhinovirus. In spite of the broad spectrum of activity of ribavirin, the drug has been approved for only one therapeutic indication—(he treatment of severe lower respiratory infections caused by RSV in carefully selected hospitalized infants and young children. 

Amantadine hydrochloride (Fig. 10.24A) does not prevent adsorption but inhibits viral penetration. It has a very narrow spectrum and is used prophylac-tically against infection with influenza A virus it has no prophylactic value with other types of influenza virus. 

Figure 11 (Left) Scheme of the polymerized bilayer assembly. The blue phase polydiyacetylene chromatic detection element is deposited over a support monolayer. The polydiacetylene chain Is asymmetrically substituted with urethane side groups partially terminated with receptor-binding ligands. (Right) Absorption spectrum of the blue and red phase PDA with a schematic representation of their chain with (red phase) and without (blue phase) influenza virus attached. Adapted figures with permission from D.H. Charych, J.O. Nagy, W. Spevak, and M.D. Bednarski, Sc/ence 261, 585 (1993), Figure 2 and 3. Copyright 1993 AAAS.

Sialic acid has later also been found to serve as receptor of a large spectrum of other viruses. Most of them will be addressed here, with emphasis, however, on influenza viruses. For additional information we refer to several excellent reviews that have been published in recent years on similar topics [6-10]. 

Figure 12.3 Colorimetric detection of influenza by sialoside bilayer assembly (2% sialoside lipid 2 and 98% matrix lipid 1). (a) The colorimetric response of the film, supported on a glass microscope slide, is readily visible to the naked eye for qualitative evaluation of the presence of virus. The film on the left (blue) has been exposed to a blank solution of PBS. The film on the right (red) has been exposed to 100 hemagglutinin units (HAU) of virus (CR = 77%). (b) The visible absorption spectrum of a...

Complications included acute respiratory distress syndrome, renal failure, and multi-organ failure. Evidence that the clinical spectrum of human H5N1 infections is not restricted to pulmonary symptoms was provided by a reported case of possible central nervous system involvement in a Vietnamese boy who presented with diarrhea, followed by coma and death. Influenza H5N1 virus was isolated from throat, rectal, blood, and cerebrospinal fluid specimens, suggesting widely disseminated viral replication. 

Antiviral spectrum Ribavirin is used in treating infants and young children infected with severe RSV infections. [Note It is not indicated for use in adults.] Favorable responses of acute hepatitis A virus and influenza A and B infections have also been reported. Ribavirin may reduce the mortality and viremia of Lassa fever. 

Ribavirin is a purine nucleoside analog exhibiting in vitro antiviral activity against a broad spectrum of DNA and RNA viruses, including clinical efficacy against both influenza A and B virus. 

Ribavirin is a synthetic guanosine analogue, with in vitro activity against a broad spectrum of DNA and RNA viruses, and retroviruses, including HIV. Ribavirin has been used for treatment of a variety of viral infections, including respiratory syncytial virus bronchiolitis and pneumonia, measles, influenza types A and B, Lassa fever, hemorrhagic fever with renal syndrome (Hantaviruses), hepatitis C, and HIV infection. It is used commonly now along with interferon alpha for treatment of hepatitis C infection. There is no known direct nephrotoxicity of ribavirin. 

Oseltamivir phosphate is an ethyl ester prodrug that lacks antiviral activity. Oseltamivir carboxylate has an antiviral spectrum and potency similar to that of zanamivir. It inhibits amantadine- and rimantadine-resistant influenza A viruses and some zanamivir-resistant variants. 

The drug is a narrow-spectrum antiviral active against almost all influenzae. A virus strains, certain C virus strains however, not found effective against B strains. It has been observed that the peripheral and central effects of the anticholinergic drugs are enhanced by concomitant use of amantidine. 

It possesses broad-spectrum antiviral activity against both DNA and RNA viruses. It exerts its maximum activity against influenza A and B and the parainfluenza group of measles, hepatitis and viruses. It is also reported to inhibit in vitro replication of HTLV-III, which is concerned with AIDS. 

More recent work on metbisazone (Y-methylisatin-l -thiosemicarbazone) has extended its antiviral spectrum from purely DNA viruses to certain RNA viruses in tissue culture. These include foot-and-mouth disease, polio, certain rhinoviruses, some arboviruses and influenza A and B. The extent of inhibition is dose dependent and is said not to be due to any toxic effect on the cells in which the viruses are grown [165]. The possibility of using any of this class of compound for treatment of these diseases in man was thought improbable. 

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