- Hello Jeff - It now appears that Tamiflu and Relenza
are not as efficient in treating Swine Flu H1N1 as the companies would
have us believe.
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- Doctors also play a role in efficacy of these drugs.
The medication MUST be prescribed and used within the 48 hour window.
Unfortunately, doctors in many cases don't use the medication in a timely
fashion.
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- Patty
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- Tamiflu Efficacy
- Source: nature.com blogs
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- The BMJ [British Medical Journal] has just published
a whole slew of papers about Tamiflu (oseltamivir) -- a key drug in the
public health response against swine flu [influenza pandemic (H1N1) 2009
virus infection].
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- The linchpin is a Cochrane review on the efficacy of
neuraminidase inhibitors -- namely zanamivir (Relenza; Glaxo Wellcome)
and oseltamivir (Tamiflu; Roche) -- for preventing and treating influenza
in healthy adults. The review found that these 2 drugs were only partly
effective against laboratory confirmed symptomatic influenza (oseltamivir
61 per cent effective; zanamivir 62 per cent effective), and no good at
all against asymptomatic flu or flu-like illness.
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- In addition, Tamiflu did not reduce the risk of influenza-related
lower respiratory tract complications -- bad news for the Department of
Health, which recommends using the drug to prevent secondary complications
in healthy adults. The authors conclude: "Neuraminidase inhibitors
might be regarded as optional for reducing the symptoms of seasonal influenza.
Paucity of good data has undermined previous findings for oseltamivir's
prevention of complications from influenza." [The abstract of this
publication is reproduced at [2] below. - Mod.CP]
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- In an accompanying feature, Deborah Cohen retraces the
steps leading to the publication of the Cochrane review and highlights
all the difficulties the authors had extracting data from Roche, the makers
of Tamiflu. The review "exposed a complex interplay between politics,
public health planning, availability of trial data, publishing, and drug
regulation."
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- Turns out that Roche's claims that Tamiflu reduces hospital
admissions and secondary complications of influenza were based on a 2003
meta-analysis that only included 2 proper randomised controlled trials
and was authored by several Roche employees. When the authors of the Cochrane
review tried to get their hands on the data in this paper to include them
in their own analysis, they came up against all sorts of obstacles thrown
up by Roche.
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- Peter Doshi, an author of the new Cochrane review, writes
in the BMJ of his struggle to get hold of the elusive data and offers a
damning verdict on the use of the drug in the swine flu epidemic. "Since
August 2009, our Cochrane review team has tried to obtain the data needed
to verify claims that oseltamivir (Tamiflu) lowers serious complications
of influenza such as pneumonia. We failed, but in failing discovered that
the public evidence base for this global public health drug is fragmented,
inconsistent, and contradictory. We are no longer sure that oseltamivir
offers a therapeutic and public health policy advantage over cheap, over
the counter drugs such as aspirin."
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- In an analysis article, Nick Freemantle and Mel Calvert
look over the observational studies of Tamiflu that Roche cited in defense
of their claims for the drug and found that they also do not support the
use of Tamiflu to treat influenza in healthy adults. In their discussion
they write: "oseltamivir may reduce the risk of pneumonia in otherwise
healthy people who contract flu. However, the absolute benefit is small,
and side effects and safety should also be considered. None of the studies
examined the role of oseltamivir in patients with H1N1 influenza, which
may be associated with higher rates of pneumonitis than seasonal influenza."
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- Finally, in a linked editorial, Fiona Godlee, editor
of the BMJ, and Mike Clarke, director of the UK Cochrane Centre in Oxford,
rail against the obstructive techniques used by Roche and call for full
data from clinical trials to be made available to the scientific community.
"Why should the public have to rely on detective work by academics
and journalists to patch together the evidence on such a potentially important
drug?" they ask.
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- All this is bad news for public health planning against
swine flu -- the Department of Health has already stockpiled more than
30 million doses of potentially useless Tamiflu -- and even worse news
for Roche.
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- http://blogs.nature.com/stories/2014 and Robo-doc: RobSci-Fi
Surgery at the Royal College of Surgeons [edited] http://www.helenjaques.co.uk/blog/2009/bmj-tamifl/
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- This moderator's opinion is that clinicians have expected
too much of the neuraminidase inhibitors Tamiflu and Relenza. The mode
of action of neuraminidase inhibitors is to bind to the influenza virus
neuraminidase protein and interfere with attachment and adsorption of the
virus. Once adsorbed there is no inhibitory effect of the drugs. Maximum
efficacy depends on treatment immediately prior to or very soon after exposure
to the virus. Any effect of treatment at later stages of influenza virus
infection is an (unexpected) bonus. Anecdotal evidence, however, suggests
that the Egyptian health care authorities have had considerable success
in reducing fatalities from avian H5N1 virus infection of children by prompt
initiation of Tamiflu treatment. - Mod.CP
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- Patricia A. Doyle DVM, PhD Bus Admin, Tropical Agricultural
Economics Univ of West Indies Please visit my "Emerging Diseases"
message board at: http://www.emergingdisease.org/phpbb/index.php Also
my new website: http://drpdoyle.tripod.com/ Zhan le Devlesa tai
sastimasa Go with God and in Good Health
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