PHARMA LAB

• Hemostatics


  Locally applied substances that are employed to arrest excessive bleeding or hemorrhage
• Hemostatic agents


  • Provide control of external bleeding when the pressure pack cannot control the bleeding
  • Enhance or accelerate the natural clotting process
• Hemostatic agents

  • Sympathomimetics
  • Mechanical Agents
  • Thrombin
• Sympathomimetics


  • Reduce bleeding by local vasoconstriction
  • Precipitate proteins in the immediate area
• Sympathomimetics that reduces bleeding by local vasoconstriction

  • Epinephrine
  • Styptics
  • Astringents
• Sympathomimetics that precipitates proteins in the immediate area

  • Zinc Chloride
  • Aluminum Chloride
  • Ferric Sulfate
• Mechanical Agents


  Act as matrices in which blood cells / fibrin can be entrapped
• Thrombin


  Normal constituent of the blood coagulation scheme, combines with fibrinogen
• Thrombin is the forerunner of granulation tissue
• Granulation tissue is the forerunner of the bone
• Stages of hemostasis

  • Vessel wall contraction
  • Adhesion and aggregation of Platelets
  • Ability of blood to coagulate
  • Fibrinolysis (breakdown of blood clot)
• Vessel wall contraction


  • Short duration (5-20 min)
  • Can be prolonged by topical or infiltration of adrenaline (vasoconstrictor)
• Platelets


  • Non-nuclear cells with a cytoplasm rich in granules
  • Normal count: 100,000 to 450,000/mL of blood
  • t1/2 is 7-10 days
  • Releases adenosine diphosphate (ADP) and thromboxane A2
• Ability of blood to coagulate

  1. Stage 1: Activation Of Factor X to Xa

  2. Stage 2: Prothrombin II to Thrombin

  3. Stage 3: Fibrinogen I to Fibrin to Clot

  4. Stage 4: Fibrin clot to lysed fibrin and fibrin peptides
• Fibrinolysis


  • Breakdown of blood clot
  • Can be influenced by age, sex, diet, smoking, altitude, exercises
• Vitamin K


  • Fat soluble vitamin that is essential for the normal hepatic biosynthesis of several factors required for blood clotting (II, VII, X)
  • Directly or indirectly interfere with the normal clotting mechanism of blood
• Heparin


  Enhances the activity of antithrombin III (neutralizes several of the activating clotting factors Ixa, Xa, XIa, and Xlia and inactivates prothrombin by forming an irreversible complex with it)
• heparin must be administered parenterally
• Vitamin K half-life

  1. 1-5 hours (the higher the dose, the higher the half-life)
• Unwanted Effects of heparin

  • Hemorrhage
  • Thrombocytopenia
• Protamine Sulfate


  • Specific antagonist to reverse the effect of Vitamin K
  • Dose regimen of 1 mg of protamine for every 100 units of heparin
• Coumarin Oral coagulants

  • Warfarin sodium
  • Phenindione
• Coumarin

  • Antagonist of vitamin K
  • Reduces synthesis of vitamin K dependent clotting factors (II, VII, IX, X)
  • Affected by diet, bowel disease pyrexia, age, pregnancy, liver disease
• Antiplatelet drugs

  • Aspirin
  • Diprydamole
  • Sulfinpyrazone
• Antiplatelet drugs
• Anti-thrombotic agents


  • Streptokinase
  • Urokinase
  • Tissue Plasminogen Activator
• Agents that encourage the stabilization of fibrin


  • Tranexamic Acid
• Tranexamic Acid


  • Maximum Child Dose: 20 mg/kg/day
  • Adult dosage: 15-25 mg/kg body weight, 2-3 times a day
• Causes of impaired hemostasis


  • Impaired Platelet Function
  • Vascular Defects
  • Impaired Coagulation
• Impaired Platelet Function


  • Due to reduction in platelet count or impaired aggregation due to drug therapy
  • Treatment: low platelet count - platelet transfusion before surgery
  • thrombocytopenia due to immune destruction of platelet - platelet transfusion before surgery
• It is wise to suture and pack the socket of newly extracted teeth to minimize the risk of post extraction hemorrhage
• Drugs that impair platelet aggregation and increase bleeding time

  • Aspirin
  • NSAIDs
  • Sodium Valproate
  • Phenytoin
• Vascular Defects


  • Associated with vitamin C deficiency and long term corticosteroid therapy
  • Patients have increased capillary fragility which can cause bleeding problems after surgery
  • Can be controlled by pressure, suturing and packing
• Impaired Coagulation


  • Hemophilia
  • Christmas Disease
  • Von Willebrand's Disease
• Hemophilia


  • Sex linked; affects only males
  • Patients have reduced factory VIII activity
  • Can be corrected by replacement therapy of freeze dried factor VIII (cryoprecipitate)
  • Drugs used in conjunction with factor VIII include anti-fibrinolytic agents, epsilon aminocaproic acid which should be started pre-operatively
• Christmas Disease


  • Associated with a deficiency of factor IX
  • Treatment via replacement therapy of factor IX (derived from plasma but not present in cryoprecipitate)
• Von Willebrand's Disease


  • Inherited disorder associated with both prolonged bleeding time and deficiency Of factor VIII
  • Replacement therapy is necessary

  
• Gelatin sponges


  • Matrices in which platelets and red blood cells can be trapped
  • Can absorb 40 to 50 times their own weight in blood which aids in coagulation
• Denatured cellulose sponge or gauze


  • Serves as a physical plug and a chemical hemostatic
  • Should not be left permanently in the wound as it could delay healing
• Collagen plug


  Accelerates the aggregation of platelets and is the preferred intra socket product