Anticoagulants Flashcards
(34 cards)
Classify anticoagulants
- used in vitro used
- in vivo -
a)parental anticoagulants -
i) Indirect thrombin inhibitor’s
ii) direct thrombin inhibitor’s
b)oral anticoagulants -
i)coumarin derivatives 
ii) indandione derivatives
iii)direct thrombin inhibitor
iv)factor Xa inhibitor
Name in vitro Anticoagulant drugs
- Heparin
- sodium citrate
- sodium oxalate
- sodium edetate
Name in the Vivo parental indirect thrombin inhibitor‘s
- Unfractionated heparin
- low molecular weight heparin‘s
- synthetic
Name low molecular weight heparin
- Enoxaparin
- Dalteparin 
- Tinzaparin
- Ardeparin
- Reviparin
Name a synthetic parenteral anticoagulant in vivo thrombin inhibitor
Fondaparinux
Name parental anticoagulants in vivo that are direct thrombin inhibitor’s
- Lepirudin
- bivalirudin
- Argatroban
Name anticoagulant used orally in vivo Coumarin derivatives
- Warfarin 
- Dicumarol
- Acenocoumarol
Name indandione derivatives
Phenindione 
Name oral anticoagulants that can be used in vivo that are direct thrombin inhibitor’s
Dibigatran
Name factor Xa inhibitor
Rivaroxaban
What is the mechanism of action of heparin
- Forms of complex with plasma antithrombin III
- Inhibits factors Xa, IIa , IXa, XIa, XIIa, XIIIa.
- Binds to thrombin and antithrombin
- low concentration, inhibits conversion of prothrombin to thrombin
- high doses, antiplatelet action
- releases lipoprotein lipase which hydrolyzes triglycerides
Why is heparin not used intramuscularly
It can cause a haematoma
If life-threatening haemorrhage occurs, which heparin antagonist/drug should be used to neutralize the effect
Protamine sulphate [strong base]
How much milligrams of protamine sulphate is needed to neutralize 100 units of heparin
1 mg
How does heparin induced thrombocytopenia in in which molecule is incidence higher
Formation of antibodies against platelet factor four – heparin complex
Incidence is higher in unfractioned heparin
What are the adverse effects of heparin
- Bleeding
- heparin induced thrombocytopenia
- hypersensitivity reactions
- osteoporosis
- reversible alopecia
- abnormalities in liver function
What are some contraindications of heparin 
- Hemophiliacs
- patients with heparin induced thrombocytopenia
- severe hypertension
- intracranial haemorrhage
- bacterial endocarditis
- active TB 
- Peptic ulcer
- threatened abortion
- cirrhosis
- renal failure
How do low molecular weight heparin’s prevent coagulation
By inhibiting factor Xa through antithrombin
What are the advantages of molecular weight heparin
- Higher subcutaneous bioavailability then UFH
- Longer half life
- They do not require aPTT monitoring
- lower incidence of thrombocytopenia and osteoporosis as compared to UFH
What are the uses of fondaparinux
They’re used for
1. pulmonary embolism
2. deep vein thrombosis
Which Drugs can be used as an anticoagulant in patients with heparin induced thrombocytopenia
Parental direct thrombin inhibitors
1. Lepirudin
2. Agratroban
What is the mechanism of action of warfarin
Warfarin competitively inhibits the synthesis of vitamin K dependent factors - II, VII, IX, and X - by inhibiting epoxide reductase enzyme
What is the duration of anticoagulant effect of warfarin
It depends on the half-lives of clotting factors. Over a period of 1 to 3 days
What is the treatment of overdosage on warfarin
Fresh frozen plasma and vitamin K1