aspirin ↓ cox inhibition ↓ (prostacyclin) pgi 2 & txa 2 (thromboxane) low dose aspirin
TRANSCRIPT
ASPIRIN↓
Cox inhibition ↓
(PROSTACYCLIN) PGI 2 & TXA 2 (THROMBOXANE)
LOW DOSE ASPIRIN
1)PREVENT ARTERIAL THROMBOSIS IHD, STROKE
2) UNSTABLE ANGINA
3) RECENT MI
4) TIA
5) ARIFICIAL VALVES
6) PTCA
7) PERIPHERAL ARTERIAL OCCLUSIVE DISEASE
8) CHRONIC LIMB ISCHEMIA
Aspirin ADR
DIPYRIDAMOLE
- VASODILATOR
- THALLIUM IMAGING
- INHIBIT PLATELET ADHESION TO VESSEL
WALL
↑ cAMP
↓ PLATELET CALCIUM
INHIBIT AGGREGATION
+ ASPIRIN – STROKE, TIA
? SUPERIOR
CLOPIDOGREL & TICLOPIDINE
INHIBIT ADP – INDUCED EXPRESSION OF PLATELET GP RECEPTORS
↓ DECREASE FIBRINOGEN BINDING
↓
DECREASE PLATELET AGGREGATION
CLOPIDOGREL → PRODRUG,
TICLOPIDINE → NEUTROPENIA
↓ CBC – 2 WEEKS UPTO 3 MONTHS
THROMBOTIC STROKE
SICKLE CELL ANEMIA
ACS
INTERMITTENT CLAUDICATION
PCI
CHRONIC ARTERIAL OCCLUSION
OPEN HEART SURGERY
AV SHUNT
ABCIXIMAB
- PCI + Aspirin & Heparin
- in MI
- Bleeding, thrombocytopenia, hypotension, Brady cardia
TIROFIBAN & EPTIFIBATIDE
- Competitive, reversible inhibitors of fibrinogen binding to GPII b / III a
- ACS – unstable angina, NSTEMI
- Angioplasty & stenting
- Bleeding
FIBRINOLYTICS:
• Streptokinase Alteplase
• Urokinase Reteplase
• Anistreplase Tenecteplase
Streptokinase 1.5 million units over 60 min
Alteplase 15mg bolus
0.75mg/1kg – 30 min
0.5mg/kg- 60 min
Reteplase – 10mg bolus
10mg after 30min
Tenecteplase – IV bolus 0.5 mg /kg
Coagulation factor concentrates
Desmopressin
HEMOSTATIC AGENTS:ε - Aminocaproic acid Aprotinin
TOPICAL ABSORBABLE: Thrombin
Microfibrillar collagen hemostat
Absorbable gelatin
Oxidized cellulose
THROMBOLYTIC THERAPY
ADV- Availability, rapid administration
DISADV – Intracranial hemorrhage
- Uncertainty of whether normal coronary flow has been restored
- Reocclusion
-Most effective within 12 hour (relative mortality decreased by 18%)
- Little benefit beyond 12 hour
Not for resolved chest pain,
ST segment depression
Fibrin selective agents should be used with
anticoagulants – UFH, LMWH,
fondraparinux & bivalirudin
Monitoring of thrombolytic therapy!
Patency is 30%
PCI patency 95% (TIMI 3)
Persistent angina
Persistent ischemic changes on ECG
<50% Reduction in ST elevation 60-90 min
after initiation of thrombolysis ---rescue PCI.
Routine coronary angiography & PCI within
24h of thrombolysis
Complications:
Intracranial bleeding 0.7 – 0.9%
Major bleeding requiring treatment 10%
Venipuncture & arterial puncture.
Diagnosis of coagulation defects
Prolonged APTT Defective Intrinsic PathwayNo change in PT
No change in APTT Defective Extrinsic PathwayProlonged PT
Prolonged APTT Defective in Common pathwayProlonged PT
Absolute C/I:1) H/o intracranial hemorrhagic / hemorrhagic stroke 2) Ischemic stroke within 3mo3) AVMs, aneurysms, tumor4) Closed head injury within 3 mo5) Aortic dissection6) severe uncontrolled HT – SBP > 180, DBP > 1107) Active bleeding / bleeding diathesis
8) Acute pericarditis.
Blood Vessel Injury
IX IXa
XI XIa
X Xa
XII XIIa
Tissue Injury
Tissue Factor
Thromboplastin
VIIa VII
X
Prothrombin Thrombin
Fibrinogen Fribrin monomer
Fibrin polymerXIII
Intrinsic Pathway Extrinsic Pathway
Factors affectedBy Heparin
Vit. K dependent FactorsAffected by Oral Anticoagulants
Thrombosis
Arterial Thrombosis : Adherence of platelets to arterial walls - White in
color - Often associated with MI, stroke and ischemia
Venous Thrombosis : Develops in areas of stagnated blood flow (deep
vein thrombosis), Red in color- Associated with Congestive Heart Failure, Cancer, Surgery.