UPDATED : My thanks to Debra MacKenzie for her comment, and link to New Scientist article from last week (Evidence that Tamiflu reduces deaths in pandemic flu) that adds even more evidence of the value of oseltamivir in severe, or complicated, influenza infection.
# 7430
There’s a short opinion piece appearing in the New Scientist today that implores governments to ignore the side-bar controversies over Roche’s release of clinical trials, and continue to stockpile (and replace) their Tamiflu ® (oseltamivir) supplies.
Don't stop stockpiling Tamiflu
- 27 June 2013
SHOULD countries continue to stockpile the flu drug Tamiflu in case there is a pandemic? Until now many governments have been happy to do so. But as stockpiles reach their "replace by" dates, cash-strapped politicians may be having second thoughts.
Their uncertainty may be being fuelled by a campaign against Tamiflu (oseltamivir), motivated by the entirely reasonable beef that manufacturer Roche has not released all of its clinical trial data.
The stockpiling and use of oseltamivir (Tamiflu) has engendered a good deal of controversy over the past decade, but it is only partially deserved. Over the years Its value has been questioned by Cochrane meta-studies, medical journals, conspiracy theorists, pundits, and the press.
Roche Pharmaceuticals has been justifiably criticized for their past refusals to release all of the testing data on their best selling antiviral drug, and that has led to critical editorials in the BMJ, and excoriation in the British press.
We’ve seen media reports of aberrant psychiatric behavior in adolescents taking the drug (see 2007 New Worries On Tamiflu), and there’s been a paucity of `gold standard’ Randomized control trials (RCTs) proving its effectiveness.
Yet, despite these negatives, there is plenty of evidence to suggest that Tamiflu does work, that it can be lifesaving with severe influenza, and that the risks of side effects have been overstated.
Which is why the CDC continues to recommend its use – particularly for high-risk influenza patients - or for the treatment of novel flu (see The CDC Responds To The Cochrane Group’s Tamiflu Study).
Regardless of one’s feeling about `Big Pharma’, the money they have made, or their parsimonious dispersal of clinical trial data, there are really only two factors that governments should consider.
- Is oseltamivir safe?
- Does it reduce morbidity and mortality in severe influenza?
First the safety issue.
Everybody seems to remember the press reports of abnormal behavior in adolescents in Japan while taking the drug, but few recall that a study in 2008 found no link between the drug and these events (see Japan: No Link Between Tamiflu And Abnormal Behavior).
In 2010 a review in the journal Eurosurveillance: Adverse Effects of Oseltamivir in Children, looked at the antiviral treatment of a number of students at a primary school in Sheffield, UK during the 2009 pandemic.
While none of the side effects reported were life-threatening, the nausea, vomiting, abdominal pain and other symptoms were bothersome enough that a minority of those who started the Tamiflu (< 10% ) stopped taking the drug.
More recently, in Study: Adverse Events Associated With Oseltamivir Outpatient Treatment, researchers writing in the journal Pharmacoepidemiology and Drug Safety, found that `no evidence was identified for an increased risk of neuropsychiatric or other AEs following oseltamivir treatment.’
The safety record of Tamiflu has been reassuring enough that last December the FDA approved its use in infants as young as two-weeks (see FDA expands Tamiflu’s use to treat children younger than 1 year).
Admittedly, all drugs have side effects, even over-the-counter medications. But the side effects of Tamiflu appear, for the most part, to be mild and manageable.
The second issue, does Tamiflu work?
While it’s value for `seasonal flu’ in healthy adults appears marginal – showing only a slight reduction in symptoms and duration of illness - for those with comorbidities, the benefits appear greater.
In 2010 an observational study appearing in JAMA (see Study: Antivirals Saved Lives Of Pregnant Women) 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.
Quite recently, in December of 2012, in Study: The Benefits Of Antiviral Therapy During the 2009 Pandemic we looked at a meta-analysis of 90 observational studies that appeared in the Journal of Infectious Diseases that spanned nearly 35,000 patients, 85% of whom has laboratory confirmed H1N1.
Their main finding was antiviral therapy - principally oseltamivir - initiated within 48 hours of onset, reduced the likelihood of severe outcomes, namely admission to a critical care unit or death, by 49 to 65%.
And lastly, for those who question the value of Tamiflu in an avian flu pandemic, in Study: Antiviral Therapy For H5N1, we saw the largest study to date on 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.
Despite the critics, the preponderance of evidence continues to show that antivirals – including Tamiflu – can have a substantial positive therapeutic effect on influenza, particularly in high risk patients.
