Respiratory season is here in Brooklyn, and with it comes the return of influenza. Just last week, we saw a significant increase (53%) in the number of positive influenza tests compared to the previous week. While the ED volume may make it seem like we’re at the peak, unfortunately, this graph from the New York State Department of Health suggests that we’re only just beginning.
With the influx of influenza-positive patients into the ED, you may to wonder if there’s anything we can do for them. Tamiflu, also known as Oseltamivir, is a drug that can help alleviate the symptoms of influenza. This drug works by inhibiting the neuraminidase enzyme of the influenza virus, preventing its replication in the body. I personally like this graphic that perfectly summarizes the mechanism of action with a giant red X.
To Tamiflu or not to Tamiflu?
But of course, some things are simply too good to be true and the lore surrounding Tamiflu is rife with controversy.
To make a long story short, Tamiflu first entered the market in 1999 and received substantial support from the CDC and WHO. It even made it onto the World Health Organization’s List of Essential Medicines from 2009 to 2017. This support was based on multiple pharmaceutical-sponsored trials that showed a ~1.5-day reduction in influenza symptoms and a reduction in secondary complications, such as hospitalizations and pneumonia. However, in a shocking turn of events, the pharmaceutical companies (namely Roche) who sponsored these trials didn’t even provide the authors with access to the data but instead simply informed them of the data’s purported findings.
This discovery brought all the data into question. Since then, numerous studies have been conducted to assess the true efficacy of Tamiflu. I’ll list some of these studies below for your review, but the bottom line is that the data supporting Tamiflu’s benefits is, at best, lackluster.
Benefits of Tamiflu:
Reduces the duration of symptoms by up to 36 hours (but more realistically around 17-24 hours) when started within 48 hours of symptom onset.
Decreases the likelihood of contracting the flu by approximately 50-80% when used as a post-exposure prophylaxis medication within 48 hours of exposure.
Risks of Tamiflu:
Nausea, vomiting, diarrhea, and/or headache occur in up to 17% of patients.
Neuropsychiatric events (including confusion, delirium, hallucinations) have been reported.
The cost of Tamiflu is around $60 for patients without insurance.
The saga and controversy of Tamiflu could go on much longer, but I’ll wrap it up here.
TLDR: The data for Tamiflu suggests a very modest reduction in the duration of symptoms (only about half to one full day) without a statistically significant reduction in complications such as hospitalizations or pneumonia. There are notable risks, including gastrointestinal distress and reports of neuropsychiatric events in children. Instead just get your flu shot.
Sources:
https://rebelem.com/the-alic4e-trial-oseltamivir-usual-care-vs-usual-care-alone/
https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/215903
https://first10em.com/tamiflu-doesnt-work/
https://rebelem.com/the-tamiflu-debacle/
Tamiflu Trials:
Jefferson T et al. Oseltamivir for Influenza in Adults and Children: Systematic Review of Clinical Study Reports and Summary of Regulatory Comments. BMJ 2014. PMID: 24811411
Krumholz HM et al. Neuraminidase Inhibitors for Influenza: The Whole Truth and Nothing but the Truth. BMJ 2014. PMID: 24811413
Okoli GN et al. Use of Neuraminidase Inhibitors for Rapid Containment of Influenza: A Systematic Review and Meta-Analysis of Individual and Household Transmission Studies. PLOS One 2014.PMID: 25490762
Qiu S et al. Effectiveness and Safety of Oseltamivir for Treating Influenza: An Updated Meta-Analysis of Clinical Trials. Infectious Diseases 2015. PMID: 26173991
Heneghan CJ et al. Neuraminidase Inhibitors for Influenza: A Systematic Review and Meta-Analysis of Regulatory and Mortality Data. Health Technology Assessment 2016. PMID: 27246259