What is different between warfarin heparin aspirin?

Answer 1

All 3 medications work in one way or another to prevent blood clot formation, some in the ARTERIES (high-pressure blood vessels), some in the VEINS (low-pressure blood vessels). Clotting is like fire or water, too much of it at the right time or some of it at the wrong time might be disastrous. For clotting to occur (thus preventing one bleeds to death) you basically need 2 ingredients (I'm grossly oversimplifying):

1) platelets and

2) coagulation factors (aka "the coagulation cascade", which I will refer to a few times during my explanation).

1) ASPIRIN: I will start with aspirin first, since you can get it over the counter and it's probably most commonly known. Aspirin inhibits platelet aggregation by inhibiting the production of thromboxane A2 (I'm oversimplifying).

There's a myth that aspirin can help you reduce the chance of developing a Deep Vein Thrombosis (DVT) during a long flight (travel does not necessarily need to be by air, it could be by any other means; actually, it's prolonged immobility --stagnant blood-- which increases the risk of DVT). Aspirin is taken by many to reduce the risk of developing heart attacks and strokes, but these events happen if ARTERIES (not VEINS) are clogged, therefore aspirin hasn't shown to decrease DVT risk.

2) HEPARIN and WARFARIN: I will comment on both of these together, since they both affect the "coagulation cascade" and therefore are quite similar in their mode of action.

HEPARIN inactivates coagulation factor Xa in the coagulation cascade, therefore inhibiting conversion of pro-thrombin to thrombin. At higher doses, heparin will also inactivate factors IX, X, XI and XII and II, therefore inhibiting conversion of fibrinogen to fibrin. I believe heparin tends to affect more the "intrinsic pathway" of the coagulation cascade.

WARFARIN (originally and still used --in the right amount and presentation-- as a rat "bleeder" poison) interferes with hepatic (liver) synthesis of vitamin k- dependent clotting factors II, VIII, IX and X. Thus, people who suffer from liver disease, may be prone to bleeding easily. Conversely, if you eat too many vitamin k-containing foods while on warfarin, you may counteract the medication's efficacy. Warfarin tends to affect more the "extrinsic pathway" of the coagulation cascade.

I hope this helps. And, please, if there are any errors on my explanation, do point them out!