#12,857
For nearly a dozen years critics have demonized neuraminidase inhibitor (NAI) antivirals (particularly Tamiflu) as either being useless, or sometimes even dangerous. The British press, in particular, has promoted these notions using hyperbolic headlines such as the Daily Mail's: Ministers blew £650MILLION on useless anti-flu drug.
Fueling this controversy have been a number of Cochrane group analyses that found insufficient evidence that oseltamivir substantially reduces seasonal influenza complications in healthy adults.Despite these damning headlines, we've seen unwavering support of the use of NAI antivirals by the CDC, ECDC (see ECDC: Expert Opinion On Use Of Neuraminidase Inhibitor Antivirals For Influenza) and other public health entities for the treatment of severe (or novel) influenza.
The reason?Because nearly every observational study over the past 10 years has shown clear benefits of using NAIs in treating high risk patients or severe influenza. A few (of many) examples include:
- 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.
- 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 even more importantly with so many novel flu viruses on the rise, in 2010’s Study: Antiviral Therapy For H5N1, a study of outcomes of H5N1 patients who either received, or did not receive, antiviral treatment found:
Today, the biggest perceived pandemic threat comes from China's H7N9 virus, and while the administration of NAI antivirals is expected to be of value, until now we've not seen those benefits quantified.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.
All of which brings us to a new study (h/t Greg Folkers for posting the link on twitter) published today in the CID Journal that tracked 160 H7N9 patients treated at a single hospital at Zhejiang University during the first 5 epidemic waves.
Patients were divided into three groups. Those who received NAI therapy within 48 hours of falling ill, those who received antivirals between days 2-5, and those who were not treated until after the 5th day.
Those who received antivirals within the first 48 hours were 60% less likely to die than those who received treatment after more than 5 days. Additionally, duration of viral shedding was reduced in patients receiving earlier NAI treatment.While there are growing concerns that H7N9 may be gaining some degree of antiviral resistance, for now 90% of infections reportedly still respond to NAI antivirals.
The full report is behind a pay wall, but follow the link below to read the abstract, which provides the gist of their findings.
Benefit of early initiation of neuraminidase inhibitor treatment to hospitalized patients with avian influenza A (H7N9) virus
Shufa Zheng Yiyin Wang Fei Yu Dawei Cui Guoliang Xie Xianzhi Yang Wen Zhang Xianfei Ye Zike zhang Xi Wang ... Show more
Clinical Infectious Diseases, cix930, https://doi.org/10.1093/cid/cix930
Published: 25 October 2017
(Excerpt)
160 patients with confirmed H7N9 infection were divided into three groups according to NAI starting time. 3 (15%) out of 20 patients for whom NAI was administered within 2 days died compared with 12 (23.1%) out of 52 patients who received treatment within 2–5 days and 33 (37.5%) out of 88 patients who were treated after 5 days (P< 0.05).
(Continue . . .)
