Images: Archenzo (L), and demott9 (R) |
In the fall of 2011 four cases of death cap mushroom poisoning
were successfully treated at Georgetown University Hospital (GUH) using a
controversial remedy – an intravenously delivered chemical extracted from the
milk thistle plant. Manufactured by the German pharmaceutical company Madaus (and
sold under the somewhat ironic name Legalon), the drug has been available in
Europe since the mid 1980s, but lacks FDA approval in the United States. Why
are U.S. citizens being denied this wunder drug? Are we simply at the mercy of
mushrooms? Can nothing be done?
As the Georgetown story unfolds, a few particularly striking
points jump out. For one thing…
Poison control centers are very, very important.
When the first of the fungus-addled patients turned up at
GUH – having eaten what he assumed were edible mushrooms picked from his yard –
physicians quickly diagnosed him with amanitin poisoning. Amanitin, the
principal toxin in the feared death cap mushroom, can be lethal. The ordeal
begins with your standard food poisoning gastrointestinal woes, but can progress
to organ failure, specifically in the liver and kidneys. In severe cases, organ
transplants are required to save a patient’s life.
Having identified the problem, the medical team’s next move
was to phone poison control. That’s right, the same people you would call if you found your child taking swigs from a bottle of laundry detergent. Poison
control put the doctors in touch with Santa Cruz physician Dr. Todd Mitchell, who
was conducting clinical trials of IV milk thistle (also called silibinin).
So if you’ve ever dismissed concerns about government funding cuts to poison control centers with a glib, “Ppfff, we don’t need those things, we’ve got emergency rooms” then
you might want to rethink your stance. Poison control doesn’t just handle calls
from panicked civilians, they also advise health care professionals tasked with treating panicked civilians.
But let’s get back to the story. Contacting Dr. Mitchell was
far from the last step in the GUH patient’s road to recovery, because as it
turns out…
Using non-approved
drugs in the U.S. is NOT easy
The FDA allows experimental drugs to be tested if there is
an established protocol and review board approval, such as in Dr. Mitchell’s
clinical trial. This doesn’t mean that every other hospital out there can also start
doling out these drugs. Luckily, the FDA does permit emergency one-time use of
an Investigational New Drug (IND), which allowed the Georgetown team to procure
and administer silibinin to their patient.
Mitchell himself went through the emergency IND process
twice, first in 2007 and then again in 2009, to treat several mycotoxin-sickened
patients (the first case was an entire family of six), before finally managing
to set up his clinical trial, sponsored by Madaus.
It having been an unusually rainy season in the DC area, the
Georgetown doctors got to work immediately writing up their protocol for any
potential future poisonings. Still, an emergency meeting of the approval
committee had to be called when a second patient materialized before everything
was in place, soon to be followed by patients three and four. In the end, all
four received the coveted silibinin and recovered without major complications
(or liver transplants) and GUH is now an approved referral center for the drug.
So why isn’t every hospital in the country running silibinin
trials? What are we waiting for? Well, mushroom poisoning isn’t especially
common in U.S. While Europeans have a long tradition of strolling through the
woods patrolling for tasty fungi, most Americans are content to buy their
mushrooms at the store. According to the journal Nature Medicine,
only about 50 cases of amanitin poisoning crop up in the U.S. annually, which
isn’t enough to motivate hospitals to plan ahead on the off chance that one
these unfortunate victims walks into their ER. But while we’re on the subject
of clinical trials…
Does anyone know if
this stuff actually works?
With all the hustling for silibinin going on, there must be
some pretty strong evidence of its efficacy against amanitin poisoning, right?
Well… not entirely. The anecdotal tales are certainly impressive. Patients on
the brink of liver failure have reportedly perked up soon after the IV
treatment began. But in the world of science, anecdotes aren’t worth much (unless
they’re anecdotes about the insane lives of famous scientists, which, of course,
are pure gold). The small number of people turning up with these maladies
limits the scope of any trial, and denying available treatment to a control
group is, well, kinda unethical.
Additionally, even in the absence of IV milk thistle,
patients do receive some treatment for death cap poisoning – including intense
hydration, penicillin, and activated charcoal (don’t worry, silibinin patients can
get these too, it’s not an either/or deal.) and many of them survive. It’s thus
difficult to determine what portion of any success story can be attributed solely
to milk thistle. Silibinin supposedly works by blocking absorption of the poison
by liver cells. It has also been tested against non-mushroom-related liver issues,
but the data thus far are underwhelming.
Perhaps Mitchell’s trial will shed some light (it’s
scheduled to wrap in late 2012), but in the meantime we can at least acknowledge
that milk thistle doesn’t seem to be making anyone sicker (which is more than can
be said for penicillin, which gives me hives and triggers anaphylactic shock in
certain unluckier individuals.) And finally...
Are mushrooms a
recipe for disaster?
Given that wild mushrooms are so potentially lethal, it
seems reasonable to suggest that we leave their harvesting to the pros. But
what fun would that be? My mother (who grew up in Russia, so it may be
inaccurate to call her an amateur) has been picking and cooking mushrooms for
decades with no reported fatalities. I’ve had them, and they’re thoroughly delicious.
(Though I did spend a wee bit more time contemplating my mortality during that
meal than I normally I do.)
Roughly 100 species of poisonous mushrooms reside in the
U.S. (out of a total of 5,000 species), so if you’re going to try your hand at
the art of mushroom hunting, please do some research first. And also note that taste and smell are not indicators of whether you’ve picked
an edible mushroom or a toxic toadstool. In fact, the death cap is said to be rather
tasty. As aptly summarized in this Croatian proverb, “All mushrooms are edible;
but some only once.”
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