Lecture 8 (hem/onc)-Exam 4 Flashcards
Venous thromboembolism txt:
* What are the parenteral agents-indirect inhibitors? (3)
- Unfractionated heparin
- Low molecular weight heparins
- Fondaparinux
Venous thromboembolism txt:
* What are the oral anticoagulants? (3)
- Vitamin K antagonists (warfarin)
- Direct factor Xa inhibitors (rivaroxaban, apixaban)
- Direct thrombin inhibitors (dabigatran)
Venous thromboembolism txt:
* What is the thrombolytics/fibrolytics?
tPA
What is primary hemostasis? Secondary hemostasis?
Extrinsic pathway
* What is activated and how?
* What is the cascade?
* What lab is ordered to monitor the extrinsic pathway?
- Tissue damage causes activated platelets from primary hemostasis to release tissue factor (TF) and Ca+
- TF and Ca+ bind to activated factor VII
- The TF/Ca+/VIIa complex cleaves factor X into activated factor X (Xa)
- Laboratory monitoring:Prothrombin time / INR
Intrinsic pathway
* When does it initiate?
* What is the cascade?
* What is the lab order to monitor?
- Initiated when blood is exposed to negatively charge surface
- Factor XII activated to XIIa
- Cleaves XI to XIa
- Cleaves IX to IXa
- IXa binds with Ca+ and VIIIa
- IXa/Ca+/VIIIa complex cleaves X to Xa
- Laboratory monitoring: Activated partial thromboplastin time
Common pathway
* What happens after X is activated?
- Xa cleaves factor V to Va
- Xa bind with Va and Ca+ to form prothrombinase complex
- Prothrombinase complex cleaves factor II (prothrombin) into IIa (thrombin)
Thrombin has several functions: (4)
- Cleaves fibrinogen (I) to fibrin (Ia) – platelet plug stabilization
- Binds to platelets – platelet activation
- Activates factors – V, VIII, XI (positive feedback)
- Cleaves stabilizing factor (factor XIII) into XIIIa
* Binds to Ca+ and forms fibrin cross links
Clot retraction
* Thrombin not directly at the site of injury binds to what?
* What happens after this? (2)
Thrombin not directly at the site of injury binds to thrombomodulin
* Thrombomodulin forms a complex with protein C and protein S
* The complex inhibits factor V and factor VIII activation and slows down clotting
- Antithrombin III (ATIII) binds what?
- What is the cascade after that?
Antithrombin III (ATIII) binds to thrombin and factor Xa making them unavailable for clotting
* Inhibits factors VII, IX, XI, and XII
* Low affinity
Fibrinolysis
* Plasminogen is activated by what?
* What happens to fibrin?
- Plasminogen is activated by tissue plasminogen activator (tPA) to form plasmin
- Fibrin gets broken down to fibrin degradation products by plasmin
What is the coagulation cascade?
Heparin, LMWH, fondaparinux: Indirect inhibition
* Heparin and low molecular weight heparins (LMWH) bind to what?
* What is ATIII?
- Heparin and low molecular weight heparins (LMWH) bind to antithrombin III and accelerates its activity
- ATIII is a natural anticoagulant that inactivates factors Xa and thrombin
What is the MOA:
* Heparin:
* LMWH:
* Fondaparinux:
Heparin
* Accelerates Xa and thrombin inactivation
LMWH
* Selectively accelerates Xa inactivation; minimal effects on thrombin
Fondaparinux
* Specifically accelerates Xa inactivation; no effects on thrombin
How does heparin, and LMWH look like?
What can the large molecule (unfractionated)-> Heparin do?
able to interact with both antithrombin III and thrombin
What are the indications of heparin? (4)
- Short-term anticoagulation (cont infusion)
- Immediate anticoagulation – rapid onset (seconds)
- MC life or limb threatening clots; surgical bridging therapy, DVT prophylaxis if other medications contraindicated
- Safe in pregnancy – does not cross the placenta (since so big)
What is the dosing of heparin?
- IV or subcutaneously (SC)
- IV: given as bolus plus continuous IV infusion (short half-life)
What are the monitoring parameter of heparin?
- aPTT [goal = 1.5 to 2.5 times normal (30 to 40 seconds)]
- Antifactor Xa level (goal=0.3 to 0.7)
- CBC (hemoglobin, hematocrit, platelets)
What are the adverse effects of heparin?
- Bleeding
- Osteoporosis – long-term therapy
- Heparin induced thrombocytopenia
What is the antidote for heparin?
- Protamine sulfate 1mg neutralizes ~ 100 units heparin
- Continuous infusions: use heparin dose from preceding 2 to 3 hours
How much antidote do you need to give if you give 1200 units of heparin per hour?
Heparin induced Thrombocytopenia
* What happens with the immune system? What does that cause?
Immune system makes antibodies that bind to heparin-platelet factor 4 complexes
* Platelet activation – aggregation (clumping)
* Clots
* Thrombocytopenia
Platelets are dropping but clots are forming
Heparin induced Thrombocytopenia
* What are the risk?
* What is the onset?
* How do you dx it? (3)
- Risk: unfractionated heparin > 7 to 10 days (also occurs with LMWH)
- Onset: 5 to 10 days after heparin initiation
Diagnosis:
* Check 4T score – probably of HIT
* Low score (≤ 3 rules out HIT); look for additional diagnoses
* High score; stop heparin, give alternative, order additional testing
HIT – alternative treatments
* What do you give more critcally ill patients?
* What do you give stable patients?
Discontinue heparin
Warfarin
* What is the moa?
- Factors II, VII, IX and X dependent on vitamin K for synthesis
- Warfarin inhibits vitamin K recycling and synthesis
- Not available for factor production
Warfarin
* What are the indications? (2)
- DVT, atrial fibrillation, prosthetics valves
- Only oral anticoagulant indicated for patients with mechanical heart valves
Warfarin-Pharmacokinetics:
* What is half life? What is onset?
* Requires what?
* How is metabolized?
- Generally long half-life; prolonged onset
- Requires bridging therapy with heparin or LMWH-> if INR therapeutic for two days then then you can stop
- Metabolized by CYP2C9 – many drug interactions
CYP2C9 inducers and inhibors? What do they cause to the levels of warfarin?
Monitoring Warfarin
* What levels do you need to look at?
* Adjuct dose to what?
* _ algorithms
* initial dose for most patients?
* What do you need to check daily intil therapeutic?
PT/INR – goal 2 to 3 in most cases
* Adjust dose to INR
* Evidence-based algorithms
* Initial dose for most patients: 5mg PO daily
* INR daily until therapeutic (then decrease interval of checking)
What are the diet issues with warfarin?
Vit K needs to be stabilized with txt
* for example: winter vs summer months
Warfarin
* What are the SE? (3)
* What is CI (1)?
Warfarin overdose:
* Txt based on what?
Treatment depends on INR level and if patient is bleeding
Warfarin overdose:
* What do you with a patient who is not bleeding? (3)
- Hold warfarin
- Give vitamin K (1 to 5 mg PO)
- Resume warfarin at lower dose once INR is 2 to 3
Warfarin overdose:
* What do you with a patient who is bleeding? (2)
- 4-factor prothrombin complex concentrate [PCC (Kcentra)] plus vitamin K -> PCC will not work without vit k
OR
* Fresh frozen plasma (FFP)
Fresh frozen plasma
Direct inhibitors
* What are the two types and their MOA?
Factor Xa inhibitors
* Directly bind factor Xa
* Prevent conversion of prothrombin to thrombin
Thrombin inhibitors
* Bind to and inhibit thrombin
Direct oral anticoagulants (DOACS)
* First oral agent since what?
* What is dadigratran?
* What are the types of oral factor Xa inhibitors (4)
Direct oral anticoagulants (DOACS)
* What are the benefits over warfarin?
- Faster onset of action
- No direct monitoring required
- Minimal drug-food interactions
- Comparable bleeding rate
- Less drug-drug interactions
- Fixed dose per indication – varies by indication, age, renal and hepatic function
- ± parenteral anticoagulation bridging
Direct oral anticoagulants (DOACS)-Indications
* Reduce risk of what?
* What does it treat?
* Prophylaxis if what?
* Not recommened as alternative when?
* Contraindicated when? ⭐️
- Reduce risk of stroke any systemic embolism in patients with nonvalvular atrial fibrillation
- Treat DVT and PE
- Prophylaxis if DVT (hip and / or knee replacement)
- Not recommended as alternative to UFH or LMWH in patients with PE who are hemodynamically unstable
- Contraindicated as anticoagulation for mechanical heart valves
DOACs – drug interactions
* What does P-glycoprotein mediate?
* Inhibits do what? Examples
* Inducers do what? Exampes?
DOACs – drug interactions
* What does CYP3A4 mediate?
* Inhibits do what? Examples
* Inducers do what? Exampes?
Fill in for DOACS
Anticoagulation for treatment of VTE
* Oral anticoagulant monotherapy with what?
* Start parenteral anticoagulant then what?
* Start parenteral anticoagulant x 5 days then switch ?
* Start parenteral* anticoagulant and what?
Fill in for Venous Thromboembolism treatment
ANTICOAGULATION TRANSITIONS
* What is complex?
* What exist?
* What is recommended?
Anticoagulation bleeding
* Anticoag are CI with what?
* What is major bleeding?
Anticoagulants contraindicated with any active bleeding
Major bleeding
* Gastrointestinal bleeding (MC) – mortality 5%
* Intracranial hemorrhage – less common – mortality 50%
* Patients can be risk stratified by age, organ function, comorbidities
Anticoagulation bleeding
* What is minor bleeding?
CONTRAINDICATIONS TO ANTICOAGULATION
* What are absolute?
CONTRAINDICATIONS TO ANTICOAGULATION
* What are relative?
Treatment of severe vte: Life-threatening pulmonary embolism with hemodynamically unstable patient
* What is first line and second line?
- First-line: IV thrombolytic therapy
- Second-line: Catheter-directed thrombolytic therapy
Massive proximal lower extremity thrombosis or ilio-femoral thrombosis associated with severe symptoms (< 14 days duration)
* What is first line?
First-line: Catheter-directed thrombolytic therapy
Treatment of severe vte
* What is last line?
Embolectomy
Tissue plasminogen activator (tpa)
* What is the MOA?
* What is the half-life?
* How do you dose it?
MOA
* binds fibrin in a thrombus and converts plasminogen to plasmin; plasmin lyses fibrin and fibrinogen breaking up the clot
Pharmacokinetics:
* Short half-life; less than 5 minutes; 80% cleared within 10 minutes
* Bolus dose followed by continuous infusion
Tissue plasminogen activator (tpa)
* What are the adverse effects?
Bleeding
* Increased risk with recent hemorrhage, trauma, surgery; uncontrolled hypertension or advanced age
Von Willebrand Disease
* Deficiency or inhibition of what?
* What are the types?
* Usually what?
* What is there is a history of?
* What is rare? What is it associated with?
Von Willebrand disease:
* Deficiency in what?
* VW stored where?
* VW released when?
* vWF attaches to what?
* vWf also carries what?
- Deficiency in quantity or quality of von Willebrand factor
- Stored in epithelial cells and megakaryocytes
- Released in response to tissue injury
- vWF attaches to exposed collagen fibers and binds to platelets via glycoprotein 1b receptors; helps bind platelets together to form platelet plug
- vWf also carries factor VIII; protects it from early degradation by proteins C and S
Von Willebrand disease
* What is prolonged?
Bleeding time may be prolonged; aPTT may be mildly elevated
Von Willebrand disease
Inherited subtypes: Type 1
* What type of disease?
* What are the sx?
Type 1 (75%)
* Autosomal dominant; quantity low, function normal
* Mild disease – bruising, bleeding gums, epistaxis, menstrual bleeding
Von Willebrand disease
Inherited subtypes: Type 2
* What type of disease?
* What are the sx?
Type 2 (20%)
* Autosomal dominant
* Variable severity; quantity good, function not good
d disease
Inherited subtypes: Type 3
* What type of disease?
* What are the sx?
Type 3 (5%)
* Autosomal recessive; no vWF and factor VIII deficiency
* Severe disease – joint, muscle, GI bleeding
vWD treatments
* What is first line for type 1 and 2?
* What is the MOA?
* How long do you use it for?
Desmopressin (DDAVP)
* Type 1 and Type 2 disease
* Stimulates endothelial cells and macrophages to release more vWF
* Used only for short periods to help control bleeding or peri-operative
Desmopressin (DDAVP)
* What is the dosing?
* What route is recommended and what is the dose?
Dosing:
* 2 hours prior to procedure and every 8 to 12 hours as needed; no more than 3 to 5 days
Intranasal spray recommended:
* < 50 kg – 150 mcg (1 spray) in single nostril
* ≥ 50 kg – 100 mcg (1 spray) in each nostril (total dose = 300 mcg)
Vwd type3 treatments
* What is the first line txt?
* What are examples?
vWF /antihemophilic factor & complexes vWF and factor VIII replacement
* What is the dose and goal?
- Dose: variable; dependent on disease and bleeding severity
- Goal: VWF: RCo activity > 50%
D. Bleeding time platelets / platelet aggregometry
B. DDAVP
Hemophilia
* What type of disease?
* What is type A and B?
* What are the sxs?
- X-linked recessive - clotting factor deficiency
- Type A is factor 8 deficiency, type B is factor 9 deficiency
- Signs/symptoms: severe bleeding, spontaneous hemarthroses, muscle hematomas, GI bleeding, bleeding with circumcision procedure
Hemophilia
* What are the labs?
* What is the txt?
- Labs: Prolonged PTT with normal PT; Factor 8 or 9 assay diagnostic
- Treatment/Management: factor 8 or 9 infusions, DDAVP, aminocaproic or tranexamic acid, avoid blood thinners, avoid trauma/contact sports if severe
Hemophilia treatment-Prophylaxis:
* Prevent what? (2)
* Geneally how many transfusions a week?
* Dependent on what?
* Given where?
sereve patients
Hemophilia treatment
* _ episode
* Stop what?
* Doses?
* Where is initial txt?
- Bleeding episode
- Stop bleeding ASAP; prevent long-term sequela
- Doses variable and dependent on severity of disease and patient activity
- Initial treatment in hospital
Hemophilia treatments-inhibitors
* Most common with who?
* What targets Factor VIII
* What happens?
* What needs to be used instead?
Hemophilia treatments
* What is the gene therapy?
- valoctocogene roxaparvovec gene therapy for severe hemophilia A
C. FactorVIII
What are the most common types of leukemia? Who does it occur in?
Acute lymphoblastic leukemia (ALL)
* MC what?
* What is the general txt?
Acute myelogenous leukemia (AML)
* MC in who?
* What is the general txt?
Chronic lymphoblastic leukemia (CLL)
* Malignancy of what?
* What is avg onset?
* What are the sxs?
* What is on smear?
- Malignancy of mature lymphoid cells
- Average onset 70 years with mean WBC >20,000 - predominantly lymphocytes
- Indolent, lymphadenopathy, HSM
- Smudge cells
Chronic lymphoblastic leukemia (CLL)
* What is the txt (3)?
- Observation vs Bruton’s TKIs (ie ibrutinib)
- Monoclonal antibodies
- Chemotherapy (purine analogs, alkylating agents
Chronic myelogenous leukemia (CML)
* Malignancy of what?
* Onset when?
* What are the sxs?
* Caused by what? ⭐️
* What is the txt? ⭐️
CML - Tyrosine kinase inhibitors
* Inhibts what? Explain the MOA?
* What does it induce?
- Inhibits BCR-ABL tyrosine kinase
- Blocks BCR-ABL’s ATP binding site; inhibiting enzyme activity and halts down stream cellular processes that lead to carcinogenic transformation
- Induces cell apoptosis
- CML treatment with TKIs improved what?
- Initial treatment of choice depends on what?
- CML treatment with TKIs improved disease outcomes with near normal lifespans
- Initial treatment of choice depends on disease mutations, patient specific factors, TKI side effect profiles
Tyrosine kinase inhibitors
* Resistance MC with what?
* Second generation agents are what?
* What is key?
* Txt is how long?
* Studies show what?
- Resistance MC with imatinib
- Second generation agents higher binding affinity and selectivity for BCR-ABL kinase binding site
- Compliance key to prevention of resistance
- Treatment generally life long
- Studies have evaluated discontinuation for patients with complete genetic remission
Tyrosine kinase inhibitors
* All metabolized by what?
CYP3A4
CLL Treatment
* What type of inhibitors?
* What are the 3 drugs?
Bruton’s tyrosine kinase (BTK) inhibitors
* Ibrutinib
* Acalabrutinib
* Zanubrutinib
CLL txt
Bruton’s tyrosine kinase (BTK) inhibitors
* Binds to what?
* Organizes what? Lymphocyte count within what?
* What occurs?
- Bind to BTK receptors within the leukemia cell and inhibit protein kinase cell signaling important for cell replication and proliferation
- Organizes B-cell migration from tissues into peripheral blood
- Lymphocyte count within blood
- stream increases temporarily
Cells death occurs
CLL treatment
* What is the efficacy?
* What are the SE?
Hodgkin’s Lymphoma
* What type of lymphoma?
* Age?
* gender?
* Presents with what?
* What is the txt?
* What happens if relapse?
Non-Hodgkin’s Lymphoma
* Common or rare?
* What types?
* Common inital therapies include what?
* What is txt in some cases?
* What is primary staging system?
* What are examples?
Hodgkin’s Lymphoma
* What is the txt drugs?
* What is the doses?
* How many cycles?
Non-Hodgkin’s Lymphoma
* What is the txt drugs?
* What is the doses?
* How many cycles?
Multiple Myeloma
* Malignacy of what?
* What is the median age?
* What is present?
* What is elevated and formed?
* What type of staging?
* What is it txt with?
What is the first line txt of multiple myeloma?
Granulocyte colony stimulating factor (GCSF)
* Stimulates what?
* prevent or reduce what? (2)
* Stimulate what?
* How do you give it?
* What is the MC SE? How do you tx this? ⭐️