New Review Highlights Tamiflu Not Proven to Reduce Complications from Influenza

Initially thought to reduce hospitalisations and serious complications from influenza, a new review highlights the drug Tamiflu is not proven and may lead to harmful effects.
The findings raise critical questions around the future of government stockpiling of such drugs for use in a pandemic. They also contrast with a paper published in The Lancet Respiratory Medicine in March 2014, which found adults hospitalised with H1N1 influenza during the 2009–2010 pandemic were 25 per cent less likely to die from the disease if they were given antiviral drugs such as Tamiflu.
Professor Peter Collignon, an Infectious Diseases Physician and Microbiologist at Canberra Hospital, Associate Executive Director of ACT Pathology and Professor of Medicine at the Australian National University said: “The earlier paper published in The Lancet Respiratory Medicine suggests that, if patients were NOT on neuraminidase inhibitors (i.e. Tamiflu) there was a 9.2 per cent death rate (959/10,431) but if they were given Tamiflu the death rate was slightly higher at 9.7% (1825/18,803). "Yet the conclusion was the opposite of this. They concluded that neuraminidase inhibitors save lives.
He said statistics done to reach that conclusion are likely to have methodological issues.
"In contrast, the new Cochrane review says there is no evidence to show that Tamiflu saves lives based on studying a similar number of patients but with much better methodology, as the patients they included were part of controlled trials (even if Roche did not let the reviewers see all the data).”
Associate Professor Jodie McVernonis a Senior Research Fellow in the Melbourne School of Population Health at the University of Melbourne, agrees.
“This latest Cochrane review finds (again) that NAIs are associated with only modest benefits in the treatment of mild-moderate seasonal influenza infection among healthy individuals participating in clinical trials. However, the study cannot tell us anything about the effects of Tamiflu in seriously ill patients who are already in hospital.
"During a pandemic, these are the patients of greatest concern, so we should be careful in our interpretation of this latest Cochrane Review. NAIs are also known to be effective in preventing the spread of symptomatic disease among contacts of infected patients, so they can help stop health services being overwhelmed during a pandemic, although they may still allow asymptomatic infection.
"So, are these new findings informative for governments considering the appropriate use of NAIs to reduce clinical cases, health sector burden and death during pandemic events, in which heightened morbidity and mortality are anticipated?
"The limitations of the randomised controlled trial are evident from synthesis of 'real world' studies conducted during the 2009 H1N1 pandemic, demonstrating that early treatment of hospitalised patients with NAIs significantly reduced ICU admissions and deaths, particularly among those with underlying poor health. In other words, the trial populations studied here just weren’t sick enough to see an effect.
"The usefulness of NAIs in prevention of secondary disease when given to household contacts of cases was further supported by observational studies during the 2009 pandemic, such as the UK’s analysis of the ‘first few hundred’ cases. Should we be concerned that asymptomatic secondary infections might occur? Not if our aim is to reduce disease burden on the health care sector and society.
"Randomised controlled trials are a ‘model system’ like any other, and necessarily fail to encompass many real world complexities of importance. Caution should be taken in extrapolating their findings without appropriate context.”