A simple nasal inhaler
can halt and even reverse venom induced paralysis and thus save the victim’s
life. Since the vast majority of snake
bites do just this, it is a blanket treatment that likely at worst is
sufficient to allow the patient to seek medical help. In many cases though, if we are reading this
correctly, it will be enough.
Needless to say,
once this is available it will become a necessity in every village at risk. Something like this really lends itself to
home care treatments were the first responder happens to be a family member.
This will
automatically become part of everyone’s hiking kit as a matter of course. An errant hand can always find a snake
anywhere however unlikely. Recall that a
stack of wood a foot away can abruptly sprout an angry snake. Snakebite is unfortunately just that easy.
New Approach To
Treating Venomous Snakebites Could Reduce Global Fatalities
by Staff Writers
San
Francisco CA (SPX) Aug 01, 2013
Antivenoms provide an imperfect solution for a
number of reasons-even if the snake has been identified and the corresponding
antivenom exists, venomous bites often occur in remote locations far from
population centers, and antivenoms are expensive, require refrigeration, and
demand significant expertise to administer and manage. File image courtesy AFP.
A
team of researchers led by Dr. Matt Lewin of the California Academy of
Sciences, in collaboration with the Department of Anesthesia at the University of
California, San Francisco, has pioneered a novel approach to treating venomous
snakebites-administering antiparalytics topically via a nasal spray. This new,
needle-free treatment may dramatically reduce the number of global snakebite
fatalities, currently estimated to be as high as 125,000 per year.
The
team demonstrated the success of the new treatment during a recent experiment
conducted at UCSF; their results have been published in the medical journal
Clinical Case Reports.
Snakebite
is one of the most neglected of tropical diseases-the number of fatalities is
comparable to that of AIDS in some developing countries. It has been
estimated that 75% of snakebite victims who die do so before they ever reach
the hospital, predominantly because there is no easy way to treat them in the
field.
Antivenoms
provide an imperfect solution for a number of reasons-even if the snake has
been identified and the corresponding antivenom exists, venomous bites often
occur in remote locations far from population centers, and antivenoms are
expensive, require refrigeration, and demand significant expertise to
administer and manage.
"In
addition to being an occupational hazard for field scientists, snakebite is a
leading cause of accidental death in the developing world, especially among
otherwise healthy young people," says Lewin, the Director of the Center
for Exploration and Travel Health at the California Academy of Sciences.
"We
are trying to change the way people think about this ancient scourge and
persistent modern tragedy by developing an inexpensive, heat-stable,
easy-to-use treatment that will at least buy people enough time to get to the
hospital for further treatment."
In
his role as Director of the Academy's Center for Exploration and Travel Health,
Lewin prepares field medicine kits for the museum's scientific expeditions
around the world and often accompanies scientists as the expedition doctor.
In
2011, Lewin put together snakebite treatment kits for the Academy's Hearst
Philippine Biodiversity Expedition, which would have required scientists to
inject themselves if they needed treatment. When he saw their apprehension
about the protocol, Lewin began to wonder if there might be an easier way to
treat snakebite in the field.
In
some fatal snakebites, victims are paralyzed by the snake's neurotoxins,
resulting in death by respiratory failure. A group of common drugs called
anticholinesterases have been used for decades to reverse chemically-induced
paralysis in operating rooms and, in intravenous form, to treat snakebite when
antivenoms are not available or not effective.
However,
it is difficult to administer intravenous drugs to treat snakebite outside of a
hospital, so Lewin began to explore the idea of a different delivery vehicle
for these antiparalytics-a nasal spray.
In
early April of 2013, Lewin and a team of anesthesiologists, led by Dr. Philip
Bickler at UCSF Medical Center, designed and completed a complex experiment
that took place at the medical center. During the experiment, a healthy human
volunteer was paralyzed, while awake, using a toxin that mimics that of cobras
and other snakes that disable their victims by paralysis.
The
experimental paralysis mimicked the effects of neurotoxic snakebite,
progressing from eye muscle weakness all the way to respiratory difficulty, in
the same order as is usually seen in envenomation. The team then
administered the nasal spray and within 20 minutes the patient had recovered.
The results of this experiment were published online in the medical
journal, Clinical Case Reports.
Later
in April, Lewin delivered one of the keynote addresses, titled "How
Expeditions Drive Clinical Research," at the American Society for Clinical
Investigation/Association of American Physicians joint meeting in Chicago,
during which he talked about this experiment and its origins.
As
a result, he met Dr. Stephen Samuel, an Indian physician and scientist from
Trinity College Dublin who was interested in collaborating in India, where an
estimated 1 million people are bitten by snakes every year, resulting in tens
of thousands of deaths. Lewin flew to India to help Samuel set up treatment
protocols at a rural hospital in Krishnagiri.
In
late June, Samuel, Dr. CS Soundara Raj and colleagues at TCR Multispeciality
Hospital in Krishnagiri, Tamil Nadu, India treated a snakebite victim using
this method. The patient was suffering from persistent facial paralysis from a
krait bite, despite having undergone a full course of antivenom treatment.
Upon
treatment with the antiparalytic nasal spray, the facial paralysis was reversed
within 30 minutes. Two weeks after being treated, the patient reported having
returned to her daily activities.
Lewin
and his colleagues in the United States are now conducting additional studies
on mice to develop new methods and drug combinations, as there are many
combinations of anticholinesterases and anticholinergic agents that could be
tried to make delivery of the drugs more predictable through the mucous
membranes in the nose or eyes. He is also working to set up future clinical
studies with Samuel, Soundara Raj and their colleagues in India.
While
there is much work in front of them, they have already taken important steps
toward addressing a major global need. The entire team has embraced the TCR
Multispeciality Hospital motto that "no patient should die from
snakebite."
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