Pharm 1 - Hemostatics, Anticoagulants, Anti-platelets & Finbrinolytics

drraythe's version from 2015-06-13 17:34


Question Answer
Mechanism of action of aspirin?Inhibits cyclooxygenase enzymes which prevents formation of thromboxane A2 (important platelet aggregating factor)
Before prescribing an anticoag, what must you do?Lab test to test efficacy of blood clotting mechanism to avoid severe hemorrhage. (Both initially & periodically)
Mechanism of heparin? (6)Inhibits antithromin 3 factor. & inhibits thrombin formation. & dec activation of factor 10. & binds to vascular endothelum & imparts a neg charge which inhibits platelet adhesion & aggregation. & improves plasminogen (converts to plasmin which works on fibrin in clots) activator synthesis. & tissue factor inhibitor (IT IS AN ANTITHROMBOTIC & ANTICOAGULANT)
Aside from anticoag, what else does hepatin do?Antithrombotic (inhibits thrombus formation)
Heparin can be used where?In vivo & in vitro
*How does oxidized cellulose promote clotting?Facilitates coagulation reaction between hemoglobin & cellulosic acid to form a matrix
*Which hemostatics are absorbable in nature?Gel sponge & microcrystalline collagen
What is vit k for in general body stuff? For treatment?Need for synth of coag factors (in liver). ESP TREAT DICUMEROL/WARFARIN (rodenticide) POISONING
What are the topical hemostatics?Thromboplastin
Fibrin foam
Absorbable gelatin sponge
Oxidized cellulose
Microcrystalline collagen
What are the systemic hemostatics?Blood
Vitamin K
Desmopressin acetate
Protamine sulfate (Acetate, Sulfate, K, Blood in the system)
Which topical hemostatic agent interferes w/ bone regeneration & epithelialization?Oxidized cellulose (plants growing right through your bones)
What are the two main anticoagulants?Heparin & Vit K antagonists ((Coumarin derivatives- bishydroxycourmarin & 3-(alpha-acetonylbenzyl)-4hydrooxycourmarin (aka warfarin)
What is the Mechanism of action, indications, side effects for vit K antagonists?Mech- inhibition of hepatic synth of vit. K dependent clotting factors (prothrombin & factors II, VII, IX, & X), acts only IN VIVO. Side effect is HEMORRHAGE!
The adverse effect of streptokinase isSystemic fibrinolysis
Aspirin can be used as an anticoag b/c it is a _________ drug?Anti-platelet drug
4 antiplatelet drugs?Aspirin
Dipyrimadole (those plates look like ASs. Theyre covered in TICks & CLOPs...they make me wanna DIe)
What does Von Willebrand's factor do?Adherence of platelets to injured site & platelet aggregation
How is epinephrine related to hemostatics?Produces immediate vasoconstriction - Controls bleeding from small vessels
Which hemostatic is absorbable?Gel sponge
*Which hemostatic can be used for sx on visceral organs?Microcrystalline collagen (tiny crystals make your organs happily shine) ESP LIVER & SPLEEN
What is the precaution you must use w/ styptics?High concentration sloughing of tissues /haemorrhage (styptic pen YOUR SKIN RIGHT OFF BITCH)
How is thromboxane A2 made?(Wiki says: It is produced by activated platelets & has prothrombotic properties: it stimulates activation of new platelets as well as increases platelet aggregation.) Phospholipase A2 makes membrane stuff into AA acid. Then thats converted by platelets (cyclooxygenases) into endoperoxidases which are then converted by thromboxane synthase into TXA2 [Kumar said: platelet COX →TXA2. I think.]
When do you especially need to treat w/ vit K?Dicumerol poisoning (rodenticide)
What does desmopressin acetate (systemic hemostatic) do? Important to note?Improves release of WVF from endothelial cells (adheres platelets then) (acetate to remove my nail polish & replace w/ WVF). Important to note: use over time will decrease effectiveness b/c of depletion of storage of VWF
What does protamine sulfate do? (Also systemic hemostatic)*Tx heparin issues. Antagonize heparin-induced hemorrhagic action (basic in nature, combines w/ acidic hepatin to form a salt which deactivates it. (ACTS w/ PROTANATED HEPARIN)
Who is an astringent & what does that mean?Styptics – precipitates the blood proteins & soft tissue & seals off the ruptured vessels
Is heparin used prophylactic or therapeutic? Side effects?BOTH. & hemorrhage as a side effect, & in Equines – decrease RBC mass (anemia); erythrocyte agglutination
Special vet applications of heparin?Veterinary: disseminated intravascular coagulation (DIC), arterial thrombi in cats; to decrease the risk factors during heartworm adulticide treatment
What are the drugs that are vit k antagonists?Bishydroxycoumarin (Dicumarol) 3-(α-acetonylbenzyl)-4-hydroxycoumarin (Warfarin sodium, Panwarfin, Coumodin)
How does the vit k antagonists work, & what is the time table like?It inhibits synth of blood coag factors. Produces actions after a certain latent period (bc some factors already in blood) 12-24 hrs to get actions.
Will tissue plasminogen factor cause systemic fibrinolysis?No - it selectively acts on plasminogen in fibrin clots
What does Ticlopidine do?(ANTI PLATELET DRUG) Blocks ADP from binding to P2Y, so maintains cAMP levels, so cAMP is then able to facilitate antiaggregatory action
What does Clopidogrel (Plavix) do?(ANTI PLATELET DRUG) same as ticlopidine, it's just a pro-drug. so, once again -- is a P2Y12 receptor inhibitor. ( blocks ADP from binding to P2Y, so maintains cAMP levels, so cAMP is then able to facilitate antiaggregatory action)
What does Dipyrimadole do?(ANTI PLATELET DRUG) inhibit phosphodiesterase enzyme (which WOULD be responsible for metabolizing the cAMP) so INC cAMP → Anti-aggregation (pyramids build up cAMPs for the phosphodiesterase slaves)
4 phases of hemostasis(1) Vascular
(2) Platelet
(3) Coagulation phase
(4) Fibrinolysis phase
About vascular phase+platelet phase (often inseparable) - refers to? What factor is important now?Changes in the blood vessel. (Vasoconstriction via myogenic reflex) release of VWF
Platelets release ...ADP, ATP, Serotonin, Thromboxane A2
Thromboxane A2 is aPlatelet aggregation factor, also a growth factor
When ADP is released form platelets it (pathway)Activates the cell membrane enzymes (phospholipase enzyme) → Arachidonic acid → Cyclooxygenase → Make prostaglandin = Inflammation (so ADP helps mediate inflammation) **ADP → Phospholipase → THROMBOXANE A2
What is arachidonic acid acted upon?Cyclooxygenase
Fibrinolytic agents (4)Streptokinase, Tissue plasminogen activator, Fibrinolysin, Urokinase (HIGH FIBER DIET of urine, Plasma, Fibrin, & Strep germs)
What is urokinase used for?Prevents serosal post-operative adhesions in abdominal sx when used as a lavage (wash the abdomen out w/ pee? LOL)