
Originally Posted by
AnabolicDoc
Please don't take aspirin while on warfarin unless instructed by your doctor. It could kill you.
Clotting happens via 2 primary mechanisms, via platelets and then coagulation factors. First platelets form a "plug" and then coagulation (aka clotting factors) factors will stabilize it. Our bodies are constantly clotting and unclotting. Warfarin was initially thought to help dissolve the clot being treated. However, now it's been found that warfarin just reduces the clotting burden on the body, thereby better enabling the body to unclot.
Despite the fact that platelets act before coagulation factors in clot formation in both arterial and venous systems, it has been shown that aspirin and other anti-platelets (such as plavix or effient) offer little protection and treatment from venous clots. Warfarin, Lovenox, and recently the addition of a whole bunch of drugs that effect the coagulation cascade, are used for the treatment and sometimes the prevention of venous clots. They are effective in the arterial system as well and occasionally used on conjunction with anti-platelet drugs (ie aspirin) depending on the reason for treatment and clinical course.
Lastly, traveling (being sedentary for long periods of time) is an independent risk factor for venous clots. Once your doctor says it's ok, you can wear venous compression stockings when flying to minimize this risk. In addition be sure to get up and stretch every so often while traveling. You may have other risk factors as well, which your doctor probably tested for the more common ones that cannot be ascertained via a history and physical exam. Of course the use of AAS, even those that don't aromatize, can increase the risk of clots. If your clot was determined to have been caused by travelling (I don't remember if u said u were using AAS at the time as well) then you should avoid cycling when you know you will be sedentary for long periods of time (ie long trips). However, if your doctor determined that you have certain other risk factors for clots, it's best if you avoid AAS use all together.
Also, tamoxifen significantly increased the risk of venous clots (DVTs). I don't believe clomid had this side effect but I am sure that the SERM with the greatest risk of DVTs is tamoxifen.