Viper Bite An Overview

Viper Bite Effects & Mechanism of Action.

1. VIPER Bite- An Overview
Compiled ByCompiled By
R. H. MishalR. H. Mishal
Asst. ProfessorAsst. Professor
Sir. Dr. M. S. Gosavi College of Sir. Dr. M. S. Gosavi College of
Pharmaceutical Education & Pharmaceutical Education &
Research, Nashik.Research, Nashik.

2. RUSSELL’S VIPER

3. Distribution of vipers and Pathogenesis of Russell’s viper Distribution of vipers and Pathogenesis of Russell’s viper
((Vipera russelliiVipera russellii) Envenomation) Envenomation
Indian Russell’s viper (Indian Russell’s viper (Daboia or Vipera russelliDaboia or Vipera russelli) specifically known as ) specifically known as
“Ghonus” is found thought the country up to sea level 3000m. “Ghonus” is found thought the country up to sea level 3000m.
Russell’s viper is varied in colour ranging from brown to yellowish brown. Russell’s viper is varied in colour ranging from brown to yellowish brown.
The underside is usually white in western or partly speckled in southeastern The underside is usually white in western or partly speckled in southeastern
& heavily speckled in northeastern races. The chain like marking of the & heavily speckled in northeastern races. The chain like marking of the
classic design shows dark round spots edged with white & black. classic design shows dark round spots edged with white & black.
Russell’s viper venom is the rich source of different enzymes including Russell’s viper venom is the rich source of different enzymes including
Phospholipase A2, ATPase, Hyaluronidase, & certain other components Phospholipase A2, ATPase, Hyaluronidase, & certain other components
which act on the different parts of the human blood & induce severe which act on the different parts of the human blood & induce severe
haemostatic disturbances in the human beings. haemostatic disturbances in the human beings.
This procoagulant activity of the Russell’s viper venom is because of the This procoagulant activity of the Russell’s viper venom is because of the
presence of specific peptide components of the venom which activate presence of specific peptide components of the venom which activate
different clotting factors in the blood including factor IX (Christmas factor), different clotting factors in the blood including factor IX (Christmas factor),
factor X (Stuart Prower factor) factor V as well as platelets. factor X (Stuart Prower factor) factor V as well as platelets.
This activation of many factors simultaneously produces a very This activation of many factors simultaneously produces a very
contradictory effect in the systemic circulation of the humans, enhancing contradictory effect in the systemic circulation of the humans, enhancing
blood clotting as well as severe haemorrhage, bleeding and haemolysis blood clotting as well as severe haemorrhage, bleeding and haemolysis
called as called as Disseminated Intravascular CoagulationDisseminated Intravascular Coagulation ( ( DIC DIC ) of the blood. ) of the blood.

4. Understanding the structure and function of Russell’s Understanding the structure and function of Russell’s
viper venom viper venom
Lethality of Russell’s viper venom is attributed to the presence of several toxins and Lethality of Russell’s viper venom is attributed to the presence of several toxins and
enzymes like phospholipase A2 (PLA2), Russell’s viper venom factor X activator enzymes like phospholipase A2 (PLA2), Russell’s viper venom factor X activator
(RVV-X), Russell’s viper venom factor V (RVV-V), proteinases, and certain (RVV-X), Russell’s viper venom factor V (RVV-V), proteinases, and certain
unidentified proteins.unidentified proteins.
Changes in the hemodynamics of the patients bitten by Russell’s viper are suggested Changes in the hemodynamics of the patients bitten by Russell’s viper are suggested
to be due to presence of proteolytic enzymes in the venom.to be due to presence of proteolytic enzymes in the venom.
(i) (i) RVV-XRVV-X: : It is mainly known for its procoagulant activity. RVV-X is the major It is mainly known for its procoagulant activity. RVV-X is the major
lethal factor in Russell’s viper venom which also affects the renal haemodynamics & lethal factor in Russell’s viper venom which also affects the renal haemodynamics &
renal functions apart from coagulation cascade.renal functions apart from coagulation cascade.
(ii) (ii) Cytotoxins:Cytotoxins: Together with cytotoxicity, cytotoxins is also responsible for Together with cytotoxicity, cytotoxins is also responsible for
neurotoxicity, cardiotoxicity & myotoxicity of the snake venom.neurotoxicity, cardiotoxicity & myotoxicity of the snake venom.
(iii) (iii) Phospholipase A2 (PLA2):Phospholipase A2 (PLA2): PLA2s are responsible for hypotensive & anti PLA2s are responsible for hypotensive & anti
platelet effect of the venom.platelet effect of the venom.
4

5. Intravascular Pathway Extravascular Pathway
FactorIX
Proconvertin
Antihaemophilia B Factor
Activated Factor
IX
Convertin
Factor X (Stuart Prower Factor) Activated Factor X
Fibrinogen Monomer
Fibrin
Sight of Venom Action Fibrin Clot
Ca
++
Ca
++

6. Disseminated Intravascular Coagulation (DIC)Disseminated Intravascular Coagulation (DIC)
Viper BiteViper Bite

7. Mode of Action of Russell’s viper
Venom
 Important elements of viper venom toxicity are the high affinity & the Important elements of viper venom toxicity are the high affinity & the
availability of the specific receptors for presynaptically toxic PLA2s. availability of the specific receptors for presynaptically toxic PLA2s.
 The basic PLA2 from The basic PLA2 from Vipera russellii Vipera russellii venom induces multiple toxic effects venom induces multiple toxic effects
like neurotoxicity, myotoxicity, edema and haemorrhage. like neurotoxicity, myotoxicity, edema and haemorrhage.
 Russell’s viper venom specifically causes lung haemorrhagic activity in the Russell’s viper venom specifically causes lung haemorrhagic activity in the
victims of the bite which is always massive in nature. victims of the bite which is always massive in nature.
 It is also reported that direct Russell’s viper bite over a vein leads to the It is also reported that direct Russell’s viper bite over a vein leads to the
direct intravenous envenoming causing myocardial infarction and myocardial direct intravenous envenoming causing myocardial infarction and myocardial
ischemia in the victim. ischemia in the victim.
 They also induce significant hypotension by perforation of capillary walls They also induce significant hypotension by perforation of capillary walls
leading to the escape of whole blood into the tissues which is the most leading to the escape of whole blood into the tissues which is the most
common symptom in viperid envenomation. common symptom in viperid envenomation.

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