Antiplatelet and thrombolytic drugs; Osmotic Diuretic (mannitol) drugs (Week 5) Flashcards
Examples of Antiplatelet drugs
Aspirin
Dipyridamole
clopidogrel
Action of Antiplatelet drugs
- Many of the antiplatelet drugs affect the cyclooxygenase pathway
- Aspirin inhibits cyclooxygenase in the platelet irreversibly so that the platelet cannot regenerate this enzyme. This results in dilation of blood vessels and prevention of platelets from aggregating or forming a clot
- Dipyridamole prevents the release of ADP, platelet factor IV, and TXA2, all substances that stimulate platelets to aggregate or form a clot.
Contraindications of antiplatelet drugs
Known drug allergy Thrombocytopenia Active bleeding Leukemia Traumatic injury GI ulcer Vitamin K deficiency Recent stroke
Adverse effects of antiplatelet drugs
- Inducing a serious bleeding episode
- Aspirin:
- CNS: Drowsiness, dizziness, confusion, flushing
- GI: Nausea, vomiting, GI bleeding, diarrhea
- Hematological: Thrombocytopenia, agranulocytosis, leukopenia, neutropenia, hemolytic anemia, bleeding
- Clopidogrel:
- Cardio: Chest pain, edema
- CNS: flu like symptoms, headache, dizziness, fatigue
- GI: Abdominal pain, diarrhea, nausea
- Misc.: Epistaxis, rash, pruritis
- Ticagrelor:
- Resp: Dyspnea (on initiation)
- Misc.: Elavated uric acid level
- GP IIB/IIIA Inhibitors
- Cardio: Bradycardia, hypotension, edema
- CNS: Dizziness
- Hematological: Bleeding, thrombocytopenia
Interactions of antiplatelet drugs
- Aspirin/NSAIDs - Decreased platelet activity - Increased bleeding risk
- Warfarin, heparin, thrombolytics - Additive - Increased bleeding risk
- Rifampin - Additive - Increased bleeding risk
- Natural health products: Garlic, Gingko, Kava - Increased effects - Increased bleeding risk
Indication of antiplatelet drugs
Dual antiplatlet therapy - post angioplasty and placement of stent and 1 year post MI
Aspirin - Stroke prevention
Clopidogrel -
Examples of thrombolytic drugs
- Ends in -ase
- Alteplase (Activase) - Acute Ischemic Stroke, Pulmonary embolism, MI
- Tenecteplase (TNKase) - MI
Action of thrombolytic drugs
- Activates the conversion of plasminogen to plasmin, which breaks down, or lyses, the thrombus. Plasmin is a proteolytic enzyme, which means that it breaks down proteins.
- It is a relatively nonspecific serine protease that is capable of degrading proteins such as fibrin, fibrinogen, and other procoagulant proteins
Contraindications of thrombolytic drugs
- Known drug allergy
- Concurrent use of other drugs that alter clotting
- Hx of recent major surgery, trauma, or bleeding (hemorrhagic stroke)
Adverse Effects of thrombolytic drugs
Internal, intracranial, and superficial bleeding Hypersensitivity Anaphylactoid reactions Nausea Vomiting Hypotension Can induce cardiac dysrhythmias
Toxicity and OD management of thrombolytic drugs
Treatment is symptomatic and supportive, as thrombolytic drugs have a relatively short half-life and no specific antidotes.
Interactions of thrombolytic drugs
Increased bleeding tendency from concurrent use of anticoagulants, antiplatelets, or other drugs that affect platelet function
Laboratory test - reduction in plasminogen and fibrinogen levels
Indications of thrombolytic drugs
The presence of a thrombus that interferes significantly with normal blood flow on either the venous or the arterial side of circulation.
- Acute MI
- Arterial Thrombosis
- DVT
- Occlusion of shunts or catheters
- Pulmonary embolism
- Acute ischemic stroke
Classifications of Mannitol
Osmotic Diuretic
Movement of Mannitol
Absorption: IV administration produces complete bioavailability. Some absorption
may follow use as a GU irrigant.
Distribution: Confined to the extracellular space; does not usually cross the
blood-brain barrier or eye.
Metabolism and Excretion: Excreted by the kidneys; minimal liver metabolism.
Half-life: 100 min.
