What is the mechanism of action for anticoagulants?

What is the mechanism of action for anticoagulants?

Anticoagulants achieve their effect by suppressing the synthesis or function of various clotting factors that are normally present in the blood. Such drugs are often used to prevent the formation of blood clots (thrombi) in the veins or arteries or the enlargement of a clot that is circulating in the bloodstream.

Why is an anticoagulant given to patients with atrial fibrillation?

INTRODUCTION Most patients with atrial fibrillation (AF) should receive long-term oral anticoagulation to decrease the risk of ischemic stroke and other embolic events. For most patients, the benefit from anticoagulation outweighs the associated increase in the risk of bleeding.

Is anticoagulation needed for paroxysmal atrial fibrillation?

American College of Chest Physicians recommended that anticoagulation be consid- ered for all patients with atrial fibrillation, whether it be chronic or paroxysmal.

Where do anticoagulants work in the clotting cascade?

Anticoagulants derive their effect by acting at different sites of the coagulation cascade. Some act directly by enzyme inhibition, while others indirectly, by binding to antithrombin or by preventing their synthesis from the liver (vitamin K dependent factors).

What are the benefits of anticoagulation?

As benefits of the anticoagulant therapy, we included reductions in stroke and all-cause mortality; intracranial haemorrhage, gastrointestinal haemorrhage, minor bleeding and myocardial infarction were considered risks.

Is coumarin and warfarin the same?

Warfarin, the only drug listed here in this category, is a coumarin. It is an oral anticoagulant that inhibits Vitamin K epoxide reductase, an enzyme that that recycles oxidized vitamin K.

What reaction is used for synthesis of coumarin?

The Perkin reaction involving salicylaldehyde and acetic anhydride is a popular method for the preparation of coumarin. The Pechmann condensation provides another reaction to form coumarin and its derivatives. The Kostanecki acylation can also be used to produce chromones.

What is the mechanism of action of coumarin?

Mechanism of Action of Coumarin Anticoagulant Drugs Coumarins are vitamin K antagonists that produce their anticoagulant effect by interfering with the cyclic inter- conversion of vitamin K and its 2,3 epoxide (vitamin K epoxide).

What is the incidence of major bleeding from coumarin anticoagulants?

Bleeding is the major complication of coumarin anticoagulants. The annual incidence of major bleeding among 4060 patients in the AFFIRM trial, who were followed for an average of 3.5 years, was about 2% per year [39 ].

Is clopidogrel plus aspirin better than oral anticoagulants for atrial fibrillation?

The combination of clopidogrel plus aspirin was recently compared with oral anticoagulants for prevention of vascular events associated with atrial fibrillation in the ACTIVE-W trial (5). This trial showed that oral anticoagulant therapy with VKAs is a better treatment than clopidogrel plus aspirin in general for patients with atrial fibrillation.

What is the best drug to prevent stroke in atrial fibrillation?

Although warfarin and similar coumarin derivatives (vitamin K antagonists, VKAs) have clearly the greatest efficacy, among treatments commonly available (mostly aspirin), in preventing stroke in atrial fibrillation They carry a substantial risk of major bleedings (approximately 1.2% per year)