Blood Drugs Flashcards
what are the 4 dysfunctions of blood
thrombosis, bleeding, circulation problems, and anemia
this is formation of a clot; causes MI, DVT, pulmonary embolism, acute ischemic stroke
thrombosis
this causes hemophilia and Vitamin K def
excessive bleeding
this is a stroke due to blockage
ischemic
this is a stroke due to bleeding
hemorrhagic
this is a clot the adheres to the vessel wall ; can be arterial or venous
thrombus
this thrombus clot is most often in medium sized vessels caused by atherosclerosis ; causes lesions on surface of endothelial cells
arterial thrombus
this thrombus clot is triggered by blood stasis or inappropriate activation of the coagulation cascade ; clot rich in fibrin
venous thrombus
what is an intravascular clot that floats in the blood
embolus
what are central to the process of hemostasis
platelets
this is cessation of blood loss from a damaged bv
hemostasis
what is the triggering stimulus for formation of a thrombus
pathologic condition
these monitor the integrity of the vascular endothelium ; circulate freely in the absence of injury; chemical mediators
resting platelets
which two chemical mediators are synthesized and act as inhibitors of platelet aggregration
prostacyclin and nitric oxide
this molecule binds to platelet membrane receptors ; receptors coupled to the synthesis of cAMP
prostacyclin
increased cAMP=
reduced ic Ca
T or F: damaged endothelial cells synthesize more prostacyclin
F; synthesize less ( decreased binding to receptors and lowers levels of cAMP)
platelet membrane has receptors for which molecules
thrombin, thromboxanes, and exposed collagen;
what is the platelet response to vascular injury
prostacyclin gears up- thrombin, thromboxanes, collagen activation- platelet adhesion- platelet activation- platelet aggregration - clot formation - fibrinolysis
what happens during the thrombin, thromboxane and exposed collagen response to vasulcar injury
circulating levels of thrombin and thromboxane are usually low > intact endothelium covers collagen in inner vascular layers > when occupied, the platelet receptors trigger a series of reactions that lead to platelet aggregation
in this part of platelet formation; there is an endothelial injury and platelets adhere to and cover the exposed collagen of the subendothelium
platelet adhesion
in this part of platelet formation; receptors on the surface of platelets are activated by the collagen ; caused morphologic changes in the platelets and the release of chemical mediators
platelet activation
what are some chemical mediators of platelet activation
ADP, Thromboxane A2, serotonin, platelet activation factor, thrombin
what do the chemical mediators of platelet activation do
they bind to circulating platelets and active the platelets -> aggregation begins
in this part of platelet formation , Ca increase inside platelets results in activation of glycoprotein receptors that bind fibrinogen; fibrinogen ( protein in plasma) binds to GP receptors on 2 separate platelets
platelet aggregation
in this part of platelet formation, thrombin Is formed as part of the activation and aggregation cascade; thrombin helps convert fibrinogen to fibrin; cross linking of the fibrin strands stabilize the clot and forms a hemostatic platelet fibrin plug
clot formation
in this part of platelet formation, plasminogen is processed to plasmin ( fibrinolysin ) ;
fibrinolysis
what limits the growth of the clot and dissolves the fibrin network as wounds heal
plasmin
with this drug, platelet activation results in release of arachidonic acid from membrane phospholipids ; arachidonic acid is converted to prostaglandin H2 by Cox 1; prostaglandin H2 is converted to Thromboxane A2
aspirin
this drug has a rapid effect; complete inactivation of platelets occurs with 160 mg daily use ; used mainly for prophylactic tx of stroke, reduced incidence of heart attack, and decreased mortality in heart attack pts
aspirin
complications of this drug include increased incidence of hemorrhagic stroke and GI bleeding
aspirin
what other drugs block COX-1
NSAIDS; can obstruct access of aspirin
which drug is the only NSAID that irreversibly exhibits antithrombotic efficacy
Aspirin
Are circulating platelets active or inactive
inactive
fibrinogen is converted to fibrin by which molecule
thrombin
this platelet aggregration inhibitor is used in the prevention of TIA and strokes in pts with previous event ; adjunct with aspiring following coronary stent implantation
ticlopidine
this platelet aggregration inhibitor is used in the prevention of atherosclerotic events following recent heart attack or stroke
clopidogrel
this platelet aggregation inhibitor is used to decrease thrombotic events in pts with acute coronary syndrome
prasugrel
what are some adverse effects of Ticlopidine, clopidigrel, prasugrel, and ticagrelor ( platelet aggregation inhibitors)
prolonged bleeding, aplastic anemia, life threatening TTP
term for when the body forms Ab against a gene coding for an important blood enzyme
TTP aka thrombotic thrombocytopenic purpura
clopidogrel, prasugrel, and ticlopidine are all what types of drugs
pro drugs; they are also poor metabolizers which have higher rates of cardiovascular events ; can all three inhibit P450 system
what type of toxicity is assoc with Ticlopidine
Phenytoin toxicity
which of the platelet aggregation inhibitors does NOT require activation
Ticagrelor; this is the only one of the platelet aggr. inhibitors that is reversible thereby not inhibiting platelet function indefinitely
with blood coagulation , how is fibrin formed
enzyme reactions produce factor Xa that converts prothrombin to thrombin
what is the role of cell surfaces in blood coagulation
each rxn takes place at a localized active cell surface; complex made of membrane surface/ an enzyme/ a substrate/ and a cofactor
T or F; coagulation should be restricted to the local site of vascular injury
T
what are some endogenous inhibitors
Protein C, protein S, Antithrombin III, tissue factor pathway inhibitor
this thrombin inhibitor is injectable and rapidly acting; high molecular weight protein ; used in the prevention of venous thrombosis , and in the tx of various thrombotic diseases
heparin
this thrombin inhibitor is used in the tx of acute DVT and pulmonary embolism; decreases incidence of recurrent thromboembolic episodes; used during and after Sx to prevent postoperative thrombosis ; does not cross placenta
heparin
adverse effects of this thrombin inhibitor include bleeding complications; hypersensitivity reactions; thrombosis ( causes reduction in antithrombin III activity); thrombocytopenia; CI in pts who have had Sx of the brain, eye, or spinal cord
heparin
which direct thrombin inhibitor is a prodrug; used for prevention of stroke in pts with atrial fibrillation; oral anticoagulant ; side effect of bleeding
dabigatran ( pradaxa)
this drug is a direct thrombin inhibitor; produced by recombinant DNA tech; pt can develop Ab which will slow renal elimination
Lepirudin
this drug is a direct thrombin inhibitor; it is metabolized in the liver
argatroban
these thrombin inhibitors selectively inhibit Factor Xa; does not have variable activity ; used in hip and knee Sx
Fondaparinux and Rivaroxaban
this vit K antagonist was originaly developed as a rodenticide; now used as oral anticoagulant; high incidence of bleeding complications and large number of drug interactions
warfarins
protein coagulation factors require Vitamin ____ as a cofactor for synthesis
Vitamin K
which drug has a narrow Therapeutic index; 99 % bound to plasma albumin; and SHOULD NEVER be used in pregnancy
warfarin
these drugs dissolve clots that have already been formed; they are used in acute thromboembolic disease; they activate the conversion of plasminogen to plasmin
thrombolytic drugs
what can occur as a result of hemophilia or during complications in Sx; Tx is natural proteins Vit K or synthetic antagonists
bleeding
what are some antibleeding meds
aminocaproic acid, protamine, and vitamin K
condition caused by below normal plasma Hb concentration; caused by toxic effects of drugs; caused by nutritional def.
anemia
this agent is used to treat anemia; its stored in intestinal mucosal cells; supplementation with ferrous sulfate is required; def. caused by blood loss, menstruation, and insuff intake during growth
iron
this agent is used to treat anemia; def. caused by pregnancy, small intestine pathology, alcoholism; def. leads to megaloblastic anemia
folate ( folic acid)
which tx of anemia is non toxic; rare hypersensitivity injections have been reported
folic acid
agent used to treat anemia ; def result from low dietary levels, poor absorption ( pernicious anemia); results in megaloblastic anemia; side effects of nausea, HA, vomiting, and rhinitis
vitamin B12
these are agents used to treat anemia caused by end stage renal disease, HIV , or Cx; HTN can result; Hb levels must be monitored
erythropoietin and darbepoetin
this is a protein that regulates rbc proliferation and differentiation into the kidney
erythropoeitin
what are some agents used to treat sickle cell
hydroxyurea and pentoxifylline
this agent increases fetal Hb levels; prevents painful crises; bone marrow suppression can result
hydroxyurea
this agent improves erythrocyte flexibility and reduces blood viscosity
pentoxyfylline
