Skip to comments.New direction for flu drugs
Posted on 02/23/2013 11:14:06 PM PST by neverdem
An international team of researchers has developed a new class of anti-flu drug that could prevent new virus strains developing resistance and help control future pandemics while more effective vaccines are prepared. Each year, flu viruses cause up to five million cases of severe illness worldwide, resulting in up to 500 000 deaths.
The preferred drug treatments for flu neuraminidase inhibitors including Tamiflu (oseltamivir) and Relenza (zanamivir) treat infection by stopping the viral surface enzyme neuraminidase from interacting with its natural substrate, sialic acid. It is this interaction that releases the virus from an infected cell and allows it to spread to other cells.
The problem, however, is that influenza viruses are constantly evolving and therefore strains have emerged that are resistant to these drugs. There is therefore a pressing need for new drugs that work in different ways.
Now, researchers in Canada, Australia and the UK have developed a new class of mechanism-based covalent compounds that inhibit neuraminidase in such a way that they think it could reduce the chances of flu viruses developing resistance.
'Our plan was to design a molecule that was as close as possible in structure to the natural substrate (sialic acid), because viruses will develop resistance most readily against drugs that radically differ in structure from the natural substrate,' says Stephen Withers, who led the study at the University of British Columbia, Vancouver.
The drugs mimic the sialic acid target of neuraminidase, then covalently attach to block its activity © AAAS
The upshot is the virus cannot mutate its key catalytic residues to stop this covalent attachment. 'If it did so, it would no longer be able to carry out its normal function. Consequently we believe that development of resistance will be much slower, if it occurs at all,' explains Withers.
The compounds have been tested on infected mice, which were completely protected against lethal infection. 'We have already shown that they work well against viral strains that are resistant to Tamiflu or Relenza. We are now embarking on tests to probe whether resistant mutations ever develop against our compounds,' says Withers.
William DeGrado, a pharmaceutical chemist at the University of California, San Francisco, US agrees that this mechanism-based covalent strategy could offer a reduced risk of developing resistance as compared to other existing neuraminidase inhibitors. 'It will be interesting to see whether robust oral bioavailibility can be obtained within this new class of mechanism-based inhibitors,' he comments.
'Oral bioavailability is something we are working on through a pro-drug approach,' says Withers. 'I am very optimistic we can do it.'
J-H Kim et al, Science, 2013, DOI: 10.1126/science.1232552
Thanks for the ping.
obamacare will not permit this for ordinary citizens. Too many old people will not die as he is prescibing and this will continue their miserble lives.
1) Someone once said "if you dont have a sword, sell your cloak and buy one."
2) Ask some moneychangers what Christianity can look like...
Then there’s going to be a lot more tables not only just turned over but chopped up and turned into firewood this time ‘round...lol
I understand the potential benefits of a flu shot, but I would rather not put myself at risk for no reason. I am 54 years old and perhaps had a bothersome case of the flu 2 or 3 times during my life On the other hand medical treatment especially when not actually needed is pretty risky
From my link above.
Iatrogenesis is a major phenomenon, and a severe risk to patients. A study carried out in 1981 more than one-third of illnesses of patients in a university hospital were iatrogenic, nearly one in ten was considered major, and, in 2% of the patients, the iatrogenic disorder ended in death. Complications were most strongly associated with exposure to drugs and medications. In another study, the main factors leading to problems were inadequate patient evaluation, lack of monitoring and follow-up, and failure to perform necessary tests.
In the United States, figures suggest estimated deaths per year of:  
12,000 due to unnecessary surgery
7,000 due to medication errors in hospitals
20,000 due to other errors in hospitals
80,000 due to nosocomial infections in hospitals
106,000 due to non-error, negative effects of drugs
Based on these figures, iatrogenesis may cause 225,000 deaths per year in the United States (excluding recognizable error).
Hospitals are the most dangerous place on earth.
You have to weigh the risk vs. the benefit for each procedure separately.
For example, the concern of having iatrogenic complications is reasonable if you are contemplating something like undergoing cosmetic surgery without a clear medical need. However, the risk of complication is extremely low with vaccines (of any kind, not just influenza), making vaccination a very reasonable precaution to take against the real risk of illness, permanent complications, and even death from the diseases they prevent.
Even if you are allergic to eggs, there may not be that much risk with flu vaccines. Recent studies have shown that most people with egg allergies tolerate the vaccines well.
The only other complication that is definitively linked to vaccines is slight pain and tenderness at the injection site, lasting a day or so. I've never had this from a flu shot, but I know people who do have that complication. They still get the shot.
Most strains of flu cause higher levels of mortality of young children (because their immune systems are still developing) and elderly people (because the immune system starts to senesce after about age 60). But even healthy adults and teens succumb to the flu. (An exception was the 1918 or "Spanish flu" which killed a disproportionately high number of young adults.) Flu kills directly, and indirectly by leaving you susceptible to bacterial infections. In many cases, you are already carrying around bacterial pathogens; they are unlikely to cause an infection until your immune system is weakened or a cut allows them to penetrate through the skin. You may have had the flu a couple of times and recovered just fine, but that is no guarantee you'll do as well the next time.
This is hard to say, but one of your best precautions against needing hospitalization (with its risk of iatrogenesis) is to avail yourself of available vaccines.
I wouldn't trade my Vit D, and kombucha for a drug store full of drugs.
A couple of weeks ago, I deliberately went to visit my friend with the flu to test my theory that we are pretty much immune to colds and flu now. She had had the flu vaccine--we won't touch them.
Each night and am. I take a glass of water with 1/2 tsp baking soda and a TBS Braggs vinegar. We do the kombucha and we're going to outlive those who spend their time going to doctors and buying expensive drugs with side effects.
Thanks for the ping!
Thank you for your concern, but.... no thanks.