Snake Bites
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Introduction
◊ There are over 3,000 species of snakes on the Planet, but only
15% are considered to be dangerous
◊ Snakes are found on every continent except Antarctica
◊ Every State except Alaska, Hawaii, and Maine are home to at
least 20 venomous snake species
◊ Each year there are 45,000 incidents of snake bites in the U.S.
• 7,000 - 8,000 are from venomous snakes
• On average 10 people die each year
◊ The literary word for snake is serpant which comes from Old
French meaning “to creep”.
◊ The snake is also used as the symbol for medicine because of
it’s relation to Asclepius, the Greek god of Medicine.
www.wikipedia.org/snakebites
Snake Venom
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Snake Venom is a Toxin (Hemotoxin Neurotoxin, or Cytotoxin)
A varied form of saliva
It is excreted through a modified parotid salivary gland
• Located on each side of the skull
• Behind the eye
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Snake venoms are a combination of proteins and enzymes
The flow of venom is produced through a pumping mechanism from an
alveolar sac that stores the venom, proceeds through a channel, down
a tubular fang which is hollow in the center to project the venom into
the air or its prey
Though the venom is dangerous, since it is not inhaled it cannot be
considered a Poison
www.wikipedia.org/snakevenom,
www.mun.ca
Benefits
◊ Although snakes have been deemed as one of the worlds most
dangerous and disgusting critters on the planet, they actually
have some benefits:
• Help control the smaller members of the animal kingdom from
becoming overpopulated
• They save farmers a minimum of seventy-five dollars annually by
ridding their fields of destructive rodents
• Snakes eat harmful rodents (mice, rats, etc.) and insects that may
carry harmful diseases
• Snakes also possess an oil that can be harvested that is used to
remedy pain in joints, such as rheumatoid arthritis. The fats and
the oils extracted from the snakes have a high content of
Eicosapentaenoic acid (EPA), hence it is thought to have
inflammation reduction properties.
http://library.thinkquest.org/CRO2
14503/benefits%200f%20snakes
Snake Video
◊ Snake Bite Video
www.bangkokpost.com,
http://www.youtube.com/watch?v
Venom
◊ Varies widely between species and even
within a species
• Geographic location
◊ ex. Mojave rattlesnake
• Age of snake
• Last feeding
http://www.reptileallsorts.com/bites-venom.htm
Venom
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90% protein by dry weight and most of these are enzymes
25 different enzymes have been isolated from venoms and 10 of these occur
frequently in most venoms
Synergistic effects: different venoms contain different combinations of enzymes
causing a more potent effect than any of the individual effects (very similar to
drug synergism)
Generally speaking, venoms are either neurotoxic, hemotoxic or cytotoxic and
the enzymes in the venom are responsible for these effects
http://www.rattlesnakebite.org/rattlesnakepics.htm
http://www.reptileallsorts.com/bites-venom.htm
Mechanism of
Toxicity
◊ The most common
types of enzymes are
proteolytic, phospholipases,
and hyaluronidases
• Proteolytic Enzymes: digestive properties
• Phospholipases: degrade lipids
• Hyaluronidases: speed venom spread
through the body
http://jrscience.wcp.muohio.edu/fieldcourses03/PapersCostaRicaArticles/VenomousSnakeG
oodness.AnA.html
http://www.reptileallsorts.com/bites-venom.htm
Mechanism of Toxicity
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Collagenases
Phosphodiesterases
Acetylcholinesterase
Circulatory System
Effects
http://jrscience.wcp.muohio.edu/fieldcourses03/PapersCostaRicaArticles/VenomousS
nakeGoodness.AnA.html
Mechanism of Action
◊ Toxic effects are the most common focus
of snake venom but often the compounds
responsible for these effects can be
isolated and used for beneficial purposes
◊ Can range from anti-venom production, to
multiple sclerosis treatment, and slowing
of cancer growth and metastasis rates
Mechanism of Action
◊ A study done in 2006
isolated denmotoxin from
mangrove catsnake venom
• Strong neurotoxic effects on
birds with little on mice
• Able to research and isolate compounds to make
discoveries in anit-coagulant, antiplatelet, and
anti-hypertensive agents as well as antiangiogenic compounds for cancer treatment
http://www.news.vcu.edu/vcu_view/pages.aspx?nid=1732
Mechanism of Action
◊ Another group of researchers isolated an
enzyme, called fibrolase, in rattlesnake
venom
• Showing great promise in dissolving blood clots,
like those associated with heart attacks, strokes,
and deep-vein thrombosis
• Clot-busting drugs on the market now dissolve the
blockages in two steps while the fibrolase directly
attacks the clots
http://www.usc.edu/hsc/info/pr/hmm/01summer/slimy.html
http://www.fotosearch.com/photos-images/rattlesnake.html
Mechanism of Action
◊ Cancer Treatment
• One study isolated a component in cobra
venom that inhibits DNA and RNA synthesis
◊ Used in the treatment of breast cancer
• Another study looked at a component of
venom called contortostatin
◊ Inhibits cancer cells from moving through blood
vessel walls, leading to fewer metastases
http://www.pps.org.pk/PJP/3-1/07%20DMShaikh.pdf
http://www.usc.edu/hsc/info/pr/hmm/01summer/slimy.html
Body Clearance
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The way in which the body clears or neutralizes venom is still not fully
understood
A recent study was done looking at the effects of antivenin (Fab/Fab2)
on the process of absorption and elimination in rabbits
They found the venom rapidly disappeared from the injection site, but
was slow to reach the vascular system, suggesting that it’s partially
absorbed in lymphatic circulation
Fab2 with antivenin elimination is slower than that of free venom with
antivenin
It suggests Fab2 is eliminated by phagocytosis
http://jpet.aspetjournals.org/cgi/content/full/285/2/490
Side Effects
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Respitory paralysis
Fever
Rapid Pulse
Increased Thirst
Dizziness
Local Tissue Damage
Blurred vision
Nausea and vomiting
Diarrhea
Coma
Death
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http://www.drugs.com/enc/snake-bite.html
www.funnyhub.com/.../img/snake
-bites-foot.jpg
Case Study # 1
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41 year old male
Bitten on left third finger by Gaboon Viper
Necrosis and Blanching noticed upon arrival to ER
Numbness and edema were also present to hand
Prothrombin time was 15.53 (normal range 11.0-13.0)
International normal ratio 1.2
There was moderate leucocytosis and normal platelets
The patient was treated with intravenous antibiotics, diphenhydramine,
hydrocortisone, and five 10ml vials of South African Institute of Medical
Research (SAIMR) antivenin.
Over next eight hours the patient developed lymphangitis of the left arm.
The patient’s lymphangitis later resolved but he later required amputation of his
left third finger.
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. Department of Emergency Medicine, University of Pennsylvania, Philadelphia, Pennsylvannia,
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http://reptilis.net/serpentes/venom.html
USA
Case Study #2
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24 year old male zoo employee
Bitten on hand while changing Gaboon Viper’s water
Noticed local Pain and nausea upon arrival to emergency room
Finger was oozing blood from the site of the bite
He was unable to move digits 1 through 4.
Dorsal Compartment pressure of the hand was greater than 40mm Hg
Prothrombin time was 26.7 sec
INR was 2.67
The patient was treated with intravenous antibiotics, diphenhydramine,
hydrocortisone, and twelve 10ml vials of South African Institute of Medical
Research (SAIMR) antivenin.
He also required local debridement and dorsal fasciotomy
Post-operatively his right hand compartment pressure and neurovascular status
normalized.
He underwent two subsequent debridements and was discharged with
outpatient physical therapy
http://reptilis.net/serpentes/venom.html
Summary
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If people are going to keeps venomous snakes as pets a safety plan
should always be put in effect to minimize effects upon envenomation.
There are many benefits of snake venom including:
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Blood clot thinner
Cancer Treatment
Eradicating pest
Remedy Joint pain such as Arthritis
Venom is 90% protein, there are 3 types of venomous snakes:
• Neurotoxic
• Hemotoxic
• Cytotoxic
http://en.wikipedia.org/wiki/Snakes
http://library.thinkquest.org/CR0214503/benefits%20of%20snakes%20page.html
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Antivenin is made by injecting horses with toxins from venomous
snakes and then monitored to make sure they survive.
Then after the horse builds up an immunity the blood is extracted and
processed into antivenin
http://www.drugs.com/enc/snake-bite.html
The End
www.funnyhub.com/.../img/snake
-bites-face.jpg
References
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Abraham, Sathya. "Toxic Snake Venom to Fight Human Disease."
http://www.news.vcu.edu/vcu_view/pages.aspx?nid=1732
Clinical Toxicology(2007) 45, 60-64
Department of Emergency Medicine, University of Pennsylvania, Philadelphia, Pennsylvannia, USA
http://en.wikipedia.org/wiki/Snakes_venom
http://en.wikipedia.org/wiki/Snakes
http://library.thinkquest.org/CR0214503/benefits%20of%20snakes%20page.html
http://jpet.aspetjournals.org/cgi/content/full/285/2/490
http://reptilis.net/serpentes/venom.html
http://www.drugs.com/enc/snake-bite.html
http://www.venomdoc.com
Levy, Paul. "Venomous Snake Goodness: An Analysis of Snake Venom Toxicity."
http://jrscience.wcp.muohio.edu/fieldcourses03/PapersCostaRicaArticles/VenomousSnakeGoodn
ess.AnA.html
McDowall, Jennifer. "Snake Venom: Bungarotoxins." http://www.ebi.ac.uk/interpro/potm/2004_
6/Page1.htm
Nalik, Jon. "The Good, the Bad, and the Slimy."
http://www.usc.edu/hsc/info/pr/hmm/01summer/slimy.html
R. Zug and Carl H. Ernst and Harrison's Principles of Internal Medicine and www.TheSnake.org;
http://www.reptileallsorts.com/bites-venom.htm
Shaikh, Din Muhammad and Rukhsana Jokhio. "The Potential of the Crude Snake Venom in Treatment of
Human Breast Cancer with and without Combination of Anticancer Drugs."
http://www.pps.org.pk/PJP/3-1/07%20DMShaikh.pdf