# 277
Just about everybody knows that Tamiflu is the primary weapon we have against the H5N1 influenza virus. It isn’t a cure, of course, but it mediates the effects of the bird flu virus (or any influenza A virus) in humans, and it is being stockpiled in large quantities by governments and organizations around the world. It is seen as both a treatment for those infected, and as a preventative for those who may be exposed.
Lesser known is the fact that when we take Tamiflu, it is excreted through our urine, largely intact. This little factoid led, a year or so ago, to the idea that were there a shortage of the drug, it might be possible to `recycle’ our own urine, and stretch out the supply of Tamiflu. This idea has lost whatever luster it might have had (thankfully), but apparently it led researchers to think about what happens when we flush our Tamiflu into the ecosystem.
Admittedly, until I’d heard about this study a couple of months ago, this had never occurred to me. I guess this is why it's a good thing we have actual scientists to study these things.
Researchers at the Centre for Ecology and Hydrology in Oxford have released findings in the January 2007 issue of Environmental Health Perspectives (EHP) in a report entitled, Potential Risks Associated with the Proposed Widespread Use of Tamiflu, that illustrate what might happen if millions of people simultaneously began taking Tamiflu and releasing it into our environment.
The concern here is that enough of the active ingredient in Tamiflu, oseltamivir carboxylate (OC), could be excreted into sewers during a pandemic and the wastewater containing this metabolite might contaminate surface water catchments. Birds, harboring various avian flu viruses, would then be exposed to the Tamiflu, and resistant influenza strains might develop.
Based on their calculations, these scientists believe enough of the metabolite OC would be present in some rivers and streams to present a genuine risk. They recommend further study of this issue, and the investigation of ways to minimize the release of these metabolites into the ecosystem.
While I doubt, in the face of an outbreak of Avian Flu, many authorities would considered halting the distribution of Tamiflu due to concerns over possible effects downstream (sorry . . . couldn't resist), this does point out that there are no simple answers when dealing with a pandemic.
