A reader wrote and asked an interesting question about Tamiflu (Oseltamivir)

” The doctor who diagnosed the influenza immediately put me on Tamiflu, which I took for ten days. I honestly felt better on Tamiflu than I have in years. By day three of the Tamiflu course, after being bedridden and sick with very high fever and some of the worst body pain I’ve ever experienced, I was full of energy and strength. I did things that haven’t been possible for me for years, like take down and pack up the Christmas tree and lift the entire thing and haul it out to the street alone. I traveled across the country alone with my daughter and felt fine the next day, even energetic the same day I got home, unpacking and doing more chores. I even wanted to exercise. This level of physical exertion would normally have me, at best, resting for a few days to recover. More than likely they would result in a full week of pain and exhaustion before finally returning to “normal bad”. I was wondering how Tamiflu might fight in your model? Or, if you think that its effects aren’t microbiome related, that I may see more health gains by pursuing and possibly even rotating antivirals.”

From Facebook Comments on post:”A friend with ME/CFS here in Iceland also experienced substantial improvement from Tamiflu.”

This is an interesting question which likely will be barely possible to answer. Here goes…

• “The drug is well-tolerated with the only clinically important side effect being mild gastrointestinal upset.” [2001] implies it does alter gut bacteria/microbiome
  • “clinical trials were nausea, vomiting, abdominal pain, ear disorder, and diarrhea” [Manufacturer]
• “This work highlights the potential for the antiviral[Tamiflu] contamination of receiving waters and indicates the risk of destabilizing wastewater treatment plants microbial consortia as a result of high concentrations of bioactive pharmaceuticals during an influenza pandemic.” [2011]
• “Tamiflu … inhibits E. Coli ATC8739, but not S.Aureus, P. aeruginosa, C. albicans”[2012]
• “The α-, β- and γ-Proteobacteria increased in OC[Tamiflu]-treated water samples” [2010]
• “In the present study, antiviral compounds were tested in a mouse model of secondary pneumococcal pneumonia [caused by Streptococcus pneumoniae] after influenza. Treatment with oseltamivir improved survival in mice from 0% to 75%, even when therapy was delayed for up to 5 days after infection with influenza virus… Previous experiments in mice that received oseltamivir beginning 48 h after infection with influenza virus demonstrated protection from secondary bacterial pneumonia [19] (figure 2) but not from influenza morbidity.” [2004]
• “All tested compounds[including acyclovir, and oseltamivir – both antivirals] (32-128 microg/ml) showed strong antimicrobial and antifungal activities against isolated strains of P. aeruginosa, A. baumanni, S. aureus, and C. krusei.” [2010]

Bottom Line

While Tamiflu is associated with the flu virus, it also have significant impact against many bacteria species. The increase of proteobacteria may be significant because low levels are seen (see this earlier post) in CFS.

• ” Proteobacteria (including Escherichia coli), and Verrucomicrobia (including Akkermansia mucinophila) are typically present in smaller numbers in the healthy gut microbiota, but these organisms have considerable potential to influence health outcomes.” [2015]

So the response does fit my model. While we have very limited information we do see an increase of an important group (proteobacteria) and a great impact on one of the Streptococcus members (mice survival jumped from 0% to 75%).

Note: Streptococcus species and strains have a high rate of antibiotic resistance. Tamiflu appears to impact some species/strains but not all. Whether Tamiflu will work depends on whether the CFS patient’s Streptococcus are resistant or not. In other words, may work for some but not all.