Does Aspirin Therapy Prevent DVTs?

One question that is consistently asked by new members of the Factor V Leiden support group is "Does taking aspirin, Plavix, or other related drugs help prevent DVTs?".

The answer is NO, it does NOT do anything to prevent DVTs. Aspirin is effective in preventing arterial clots, but has no effect in preventing venous clots (DVT = Deep VEIN Thrombosis). Aspirin also does not affect your INR.

Venous clots are mostly made up of proteins, whereas arterial clots are due to platelets. If you have Factor V Leiden and DVTs, you need a medication such as Lovenox or Warfarin to prevent those specific kind of clots.

If your doctor tells you aspirin will prevent DVTs, and many do, get a second opinion or go see a specialist such as a hematologist. Of course, don't stop taking aspirin if your doctor prescribes it because their intentions might be to stop arterial clotting for whatever reasons. Arterial clots can cause heart attacks and strokes.

But realize aspirin will not prevent you from getting DVTs or having a PE, or stroke due to a DVT clot.