Friday, January 20, 2012

The Tamiflu Controversy Continues




Photo Credit – Wikipedia  

# 6085



The debate over the effectiveness of oseltamivir (Tamiflu ®) is back in the news once more with the release of a new Cochrane group analysis that finds insufficient evidence to prove that the drug reduces flu complications and transmission.


If it seems we’ve been here before, you are right (see Effect Measure’s The Tamiflu doesn't work non-story from 2009).


Many researchers point out anecdotal and observational data showing that early administration of oseltamivir does reduce complications from influenza, and can be lifesaving.


As an example, In 2010 we saw an observational study that appeared in JAMA  (see Study: Antivirals Saved Lives Of Pregnant Women) that strongly suggested that Tamiflu was life saving for some patients with pandemic flu.


And again in 2010, in BMJ: Efficacy of Oseltamivir In Mild H1N1, we saw a study which suggested that the administration of oseltamivir may have significantly reduced the incidence of pneumonia among otherwise healthy pandemic H1N1 patients.


And lastly, in Study: Antiviral Therapy For H5N1, we saw the largest study to date on the outcomes of H5N1 patients who either received, or did not receive, antiviral treatment.


The research appears in the IDSA’s  Journal of Infectious Diseases. The bottom line is essentially out of 308 cases studied, the overall survival rate was a dismal 43.5%.


But . . . of those who received at least one dose of Tamiflu . . .  60% survived . . .  as opposed to only 24% who received no antivirals.



Alas, these are observational studies, which are not considered the `best evidence’ by most scientists.


Ideally what researchers want are a series of well mounted Randomized controlled trials (RCTs) – long considered the `gold standard’ for drug research. But these are expensive, and difficult to conduct ethically when trying to evaluate a potentially life saving drug.


So we are left with is a choice that reminds one of the one offered by Chico Marx in the 1933 classic Duck Soup (Who you gonna believe, me or your own eyes?”).


Choosing between observational data that suggests a clinical benefit verses a lack of well mounted studies that actually prove a benefit.


Complicating matters, there are ongoing charges that Roche Laboratories has not been forthcoming with all of the data that has been requested by the Cochrane group.


Admittedly, there are other concerns when it comes to use of oseltamivir, including the possibility of incurring side effects and the (potential, at least) of generating resistant strains of the influenza virus.


Robert Roos of CIDRAP News takes us on a detailed journey down this rabbit hole, with as good a summary of the issues as you are apt to find anywhere.


Review renews questions about oseltamivir benefits

Robert Roos * News Editor

Jan 19, 2012 (CIDRAP News) – A lengthy new analysis of unpublished clinical trial data is renewing questions about the effectiveness of the influenza drug oseltamivir (Tamiflu), saying that although the drug shortens flu symptoms by about a day, there is no evidence that it reduces hospital admissions.

(Continue . . .)


Despite a lot of unanswered questions, for now at least, oseltamivir remains one of the few pharmacological options likely to be available during a pandemic.

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