best clinical management for H5N1(could apply toH1N)1

indigo girl · Jun 24, 2009

http://www.medicalnewstoday.com/articles/155052.php

One group of scientists wants to give a bigger dose of Tamiflu than WHO currently recommends to treat bird flu cases. It's understandable.

Most of the time, (except for the very recent, unexplained phenomenon of toddlers developing only mild cases in Egypt), infected individuals will die in 6 out of 10 cases. Better make that 8 out of 10 cases if in Indonesia. This is even with the current Tamiflu regimen, so there is an urgent need to find a way to save them. Bird flu is still infecting people, and is considered a very virulent virus with pandemic potential. It will very likely continue to expand its geographic range, and most of us have no immunity to it.

...to avoid any possibility of under-dosing those patients with unusual pharmacokinetics and more resistant organisms.
This will come at the expense of increased toxicity, he says, but is necessary given the mortality burden of H5N1 infection and the fact that H5N1 replicates more rapidly than seasonal influenza viruses, reaches much greater viral burdens than do other human influenza viruses, and resistance develops swiftly.

I don't know. Does resistance develop swiftly? There was some resistance in northern Egypt a few years ago, but none recently that I have heard of. But, at some point, resistance is bound to occur from the sheer amount of Tamiflu being dispensed on the planet between bird flu cases in Egypt and Asia, and the swine flu pandemic. Our seasonal influenza, H1N1 has just developed Tamiflu resistance in the past year. This does not bode well for use of this drug with either bird or swine flu, and then what will we have to use?

That brings us to the other side of the debate, which seems a much smarter approach to me. The use of a multidrug cocktail works well with TB and HIV. Why not with influenza? Tamiflu and Relenza are the only antivirals available for tx of both swine and bird flu. These are neuraminidase inhibitors that can shorten the duration and lessen the severity of influenza.

Tamiflu is marketed by Roche. It inhibits the neuraminidase protein, so that the virus can't leave the cell to infect other cells, and eventually the virus dies out. You have to take it within 48 hours of showing symptoms.

Relenza (Zanamivir) is marketed by GlaxoSmithKline. It is not taken po. It must be inhaled. Relenza inhibits a viral enzyme called neuraminidase to prevent the release of the virus from infected cells so that it prevents other cells from being infected.

We currently find ourselves in the very foolish position of having unwisely put all of our eggs in one basket. It would appear that we are on borrowed time before these influenza viruses develop resistance to these antivirals.

...consider a multidrug approach to managing patients with H5N1, an approach that is supported by animal data and "can guard against the emergence of resistant strains." Tim Uyeki from the Centers for Disease Control and Prevention in Atlanta, USA, emphasizes the need for more data to help inform clinical management of patients with H5N1 infections. In the absence of these data, he argues, we need a multipronged strategy: pharmacological strategies including combination antiviral treatment, anti-inflammatory agents, and immunotherapy, and non-pharmacological strategies such as the standardization of optimal ventilator and fluid management, especially for acute respiratory distress syndrome, and management of other complications.