The article that I refer to as my "bible" on anticoagulation is "Guide to Anticoagulant Therapy art 2: Oral Anticoagulants," by Jack Hirsh, MD; Valentin Fuster, MD, PhD, l998. It is an American Heart Associatiion Medical/Scientific Statement paper that is on their web site, www.americanheart.org. Search the term "anticoagulant therapy." I hope the following will answer some of the questions that seem to keep coming up.
"Warfin is the most widely used oral anticoagulant in North America because its onset and duration of action are predictable and because of it has excellent bioavailability.....(this is the important part) It is rapidly absorbed from the gastrointestinal tract, reaches maximal blood concentrations in healthy volunteers in 90 minutes, and has a half-life of 36 to 42 hours." (What this says to me is that it gets there quickly--90 minutes, and stays around a long time--at the end of 36-42 hours, half of it is still in the system doing its job. For me, this explained how one could take different daily doses and still maintain a level INR. You don't start over each day--it kind of averages out. The quote is on p.2.
Reading the posts on asprin caused me concern because Al takes one .8l encoated asprin each day. The paper states, "Serious bleeding does occur when high doses of asprin (more than l g/d) and high-intensity warfin therapy are used in combination. However, low doses of asprin (eg, 100 mg) that have minimal gastric side effects but antithrombotic efficacy can be used with relative safety in combination with warfin." (p.3)
Under Adverse Effects, p. 13, I found the following important. "The risk of bleeding is influenced by the intensity of anticoagulant therapy and is reduced dramatically by lowerig the INR range from 3.0-4.5 to 2.0-3.0. Although this difference in anticoagulant intensity is produced by a reduction of the dose of warfin by only approximately 1 mg, the effect on bleeding is profound." In an earlier portion of this paper, they recommend a target of 2.5 to 3.5 for prosthetic heart valve patients. (p. 11)
I've already exceeded space here. I'll post some info on Vitamin K this week. As a preview, even with anticoagulation, the body needs vitamin K for other important functions, not the least of which is for maintaining healthy bone density. I hope everyone is taking calcium (at least l500 mg per day). Al's recent bone scan shows severe osteoporosis. Anyone have experience with the drug Fosamax?
I hope this info helps. The paper comes from an undisputed authority, the AHA. Your doctor won't say, "that's just one guy's opinion," if you quote the AHA.
Regards to all, Blanche
"Warfin is the most widely used oral anticoagulant in North America because its onset and duration of action are predictable and because of it has excellent bioavailability.....(this is the important part) It is rapidly absorbed from the gastrointestinal tract, reaches maximal blood concentrations in healthy volunteers in 90 minutes, and has a half-life of 36 to 42 hours." (What this says to me is that it gets there quickly--90 minutes, and stays around a long time--at the end of 36-42 hours, half of it is still in the system doing its job. For me, this explained how one could take different daily doses and still maintain a level INR. You don't start over each day--it kind of averages out. The quote is on p.2.
Reading the posts on asprin caused me concern because Al takes one .8l encoated asprin each day. The paper states, "Serious bleeding does occur when high doses of asprin (more than l g/d) and high-intensity warfin therapy are used in combination. However, low doses of asprin (eg, 100 mg) that have minimal gastric side effects but antithrombotic efficacy can be used with relative safety in combination with warfin." (p.3)
Under Adverse Effects, p. 13, I found the following important. "The risk of bleeding is influenced by the intensity of anticoagulant therapy and is reduced dramatically by lowerig the INR range from 3.0-4.5 to 2.0-3.0. Although this difference in anticoagulant intensity is produced by a reduction of the dose of warfin by only approximately 1 mg, the effect on bleeding is profound." In an earlier portion of this paper, they recommend a target of 2.5 to 3.5 for prosthetic heart valve patients. (p. 11)
I've already exceeded space here. I'll post some info on Vitamin K this week. As a preview, even with anticoagulation, the body needs vitamin K for other important functions, not the least of which is for maintaining healthy bone density. I hope everyone is taking calcium (at least l500 mg per day). Al's recent bone scan shows severe osteoporosis. Anyone have experience with the drug Fosamax?
I hope this info helps. The paper comes from an undisputed authority, the AHA. Your doctor won't say, "that's just one guy's opinion," if you quote the AHA.
Regards to all, Blanche
