Hemostatics, Anticoagulants, Fibrinolytics, and Anti-platelet Drugs Flashcards
Thromboplastin MOA
hemostatic
promotes conversion of prothrombin to thrombin
Thromboplastin therapeutic use
used in labs to measure prothrombin time during anticoagulant therapy
Where is thromboplastin from?
naturally priduced by platelets/tissues
powder extracted from bovine brain/acetone-extracted lungs
How is thromboplastin applied?
applied by a spray or a sponge
Thrombin MOA
hemostatic
converts endogenous fibrinogen to fibrin for clot formation
Thrombin therapeutic use
control bleeding from parenchymatous tissue, cancellous bone, dental sockets, laryngeal/nasal surgery, reconstructive surgery
adhesive agent for fixation of skin grafts
Thrombin adverse effects
not recommened for parenteral administration
IV administration = extensive intravascular clotting
SC/IM = local ischemia
How is thrombin applied?
applied topically as a powder/solution
Fibrinogen MOA
hemostatic
requires endogenous thrombin for conversion of fibrinogen to fibrin
Fibrinogen therapeutic use
control bleeding from denuded mucous membranes
adhesive in skin grafts
massive blood loss/acute hypofibrinogemia
Fibrin foam MOA
hemostatic
traps blood oozing from the surface area
Fibrin foam therapeutic use
applied directly with pressure after pre-soaking in thrombin solution
Is fibrin foam soluble?
NO - insoluble substance
Describe fibrin foam
strips of white sponge like material prepared from human fibrinogen
Absorbable geltatin sponge (Gelfoam) MOA
hemostatic
absorbs several times its weight of whole blood
Absorbable gelatin sponge therapeutic use
capillary/venous bleeding
How is absorable gelatin sponge applied?
soaked in bovine thrombin and applied over the bleeding area
How long does it take for gelfoam to liquify and then absorb?
liquifies in 3-5 days
completely absorbs in 4-6 weeks
Oxidized cellulose MOA
hemostatic
facilitates coagulation reaction between hemoglobin and cellulosic acid
forms a gummy matrix to facilitate clot formation
Oxidized cellulose therapeutic use
used as temporary packing
Oxidized cellulose adverse effects
permanent implantation may interfere with bone regeneration and epithelialization
cyst formation
can delay wound healing
How is oxidized cellulose applied?
surgical gauze/sponge
Microcrystalline collagen MOA
hemostatic
surface hemostatic agent
Microcrystalline collagen therapeutic use
treatment of clotting factor deficiencies
surgery of liver and spleen
Application and duration of microcrystalline collagen
abdorable sponge - 6 weeks
Epinephrine MOA
hemostatic
alpha 1 agonist
produces immediate vasoconstriction
Epinephrine therapeutic use
vasoconstrictor - controls bleeding from small vessels
Hemostatic dressing - alginate therapeutic use
excessive bleeding
Describe the hemostatic dressing - quikclot
non-antigenic kaolin impregnanted polyester gauze
Hemostatic dressing - quikclot MOA
factor XII activation
Describe the hemostatic dressing - chitosan
organic polymer from crustacean shells
Styptics MOA
locally acting hemostatic
astringent substances
precipitates blood proteins and soft tissue and seals off ruptured vessels
Styptics adverse effects
high concentrations = sloughing of tissues/hemorrhage
How are styptics applied?
powders dusted onto the bleeding area
Blood therapeutic use (as a hemostatic)
emergency treatment of acute hemorrhagic syndrome with deficiency of clotting factors/platelets
Vitamin K MOA
hemostatic
aids in the production of clotting factors II, VII, IX, and X
produces active protein C and S - anticoagulants
Vitamin K therapeutic uses
ingestion of vitamin K antagonist
sweet clover poisoning
rodenticide poisoning
Vitamin K adverse reactions
IV administration can cause anaphylaxis
Unique feature of Vitamin K
safe for parenteral administration
fatty meals enhance oral absorption
Desmopressin acetate MOA
hemostatic
releases stored vonWillebran factor from endothelial cells and macrophages
Desmopressin acetate therapeutic use
controls capillary bleeding from wounds
vWF diease
hemophillia A
thrombocytopenia
Desmopressin acetate adverse effects
repeated administration reduces effectiveness of drugs
Protamine sulfate MOA
hemostatic
interferes with the reaction of thrombin and fibrinogen
Protamine sulfate therapeutic use
antagonize heparin-induced hemorrhagic action
Where does protamine sulfate come from?
fish sperm
How is protamine sulfate administered?
slow IV
Heparin MOA
anticoagulant
binds reversibly to antithrombin III - inhibits thrombin and factor Xa
binds to endothelial cells - neg charge - inhibits platelet adhesion and aggregation
increases plasminogen activator and tissue factor inhibitor
Heparin therapeutic use
disseminated intravascular coagaulation
arterial thrombi - cats
decrease risk factors during heartworm adulticide treatment
thromboemboli
prevent thrombosis and pulmonary embolism
Heparin adverse effects
hemorrhage
IV = hematoma
equines - anemia
Where is heparin metabolized?
liver
Antitode for heparin toxicity
protamine supplemented with fresh blood
Examples of vitamin K antagonists
dicumarol
warfarin sodium
Vitamin K antagonist MOA
anticoagulant
inhibition of hepatic synthesis of Vit K dependent clotting factors (factors II, VII, IX, and X)
anticoagulant activity after 12-24 hours
Duration of action of Vitamin K antagonists
2-5 days
Vitamin K antagonist therapeutic use
prophylaxis and treatment of venous thrombosis
Vitamin K antagonist adverse effects
hemorrhage
Where are vitamin K antagonists metabolized and stored?
metabolized and stored in the liver
Streptokinase MOA
fibrinolytic
complexes with plasminogen to produce plasmin
Streptokinase therapeutic use
eczema
dermatitis
cellulitis
hematoma
trauma
sinusitis
cysts
fractures with fistulous tracts
Streptokinase adverse effects
systemic fibrinolysis
Where does streptokinase come from?
from beta-hemolytic streptococcus spp.
How long does it take for streptokinase to work?
liquifation of blood clot occurs in 30min-12hours
Tissue plasminogen and Aletplase MOA
fibrinolytic
selectively acts on plasminogen in fibrin clots
Tissue plasminogen and Aletplase therapeutic use
lysis on aortic thromboemboli in cats
good for acute myocardial infraction or brain stroke
Antidote for tissue plasminogen toxicity
antiplasmin
Urokinase MOA
fibrinolytic
activator of plasminogen
Urokinase therapeutic use
used in dogs to prevent post-op adhesions when administered as a lavage into peritoneal cavity
Where is urokinase from?
isolated from human urine
Asprin MOA
anti-platelet drug
irreversibly binds COX - inhibits prostaglandin production and thromboxane A2 production
Asprin therapeutic use
NSAID
used in dogs to decrease the severity of heartworm emboli
blood thinner in dogs and cats
Ticlopidine MOA
anti-platelet drug
P2Y12 receptor inhibitor on platelets - inhibits aggregation
Clopidogrel MOA
anti-platelet
prodrug - biotransformed into active drug
Clopidogrel therapeutic use
commonly used with asprin
safe to use in cats for arterial thrombi
Dipyridamole MOA
anti-platelet
inhibits phosphodiesterase - increase cAMP in platelet - prevents aggregation
Dipyridamole therapeutic use
synergistic with asprin
little effect if used alone