November 4th, 2015
Antiplatelet agents, anticoagulant agents (anti-clotting agents) and thrombolytic agents are drugs that interfere with the blood’s ability to clot and prevent blood clots from forming. There are actually three types of them but most people (even doctors) are often mistaken that they are all the same and mix up their names, functions and qualities.
First of all, it is important to know that blood clotting is a defense mechanism of the body when there is an injury either internal or external. Platelets will form around the wound and stimulate protein in the blood to create blood clots to stop the bleeding and fix the tissues around that area. For external wound, you can see scab where the wound is. This is to prevent blood from leaving the body or leaking into internal organs. The clotting of the blood starts at the platelets.
If the wound occurs at the blood vessel that supplies blood to the heart muscles, the platelets and blood clots will form. If they exceed a certain amount, the clots can cause acute myocardial infarction. To prevent acute coronary thrombosis or acute myocardial infarction, the use of all three types of antiplatelet agents can be of great help. That is in different timing, though.
Antiplatelet agents work by preventing the platelets in the blood from clumping. Examples of antiplatelets include aspirin, clopidogrel, a super aspirin.
Anticoagulants act against clotting factors which are the proteins made in the liver. Examples of anticoagulants are heparin, which must be injected under the skin or into the vein, and cumadin or warfarin which is commercially known as Orfarin available in Thailand in tablets.
Thrombolytic agents are used to dissolve blood clots that have already formed in the body (platelets have already formed and proteins in the blood are already active). Normally the body can dissolve blood clots on its own but in some cases such as acute myocardial infarction or paralysis caused by clogged arteries, it is important to dissolve the clots as soon as possible. It will be too late to wait for the body to rid the clots on its own, therefore medication is needed in order to help with the dissolving. The medications used today are quite expensive and must be injected only. Edible tablets are not yet available.
Antiplatelet agents, anticoagulant agents (anti-clotting agents) and thrombolytic agents are all different as I have mentioned before, but please do not forget that clotting is the body’s natural healing process. To expect the medicine to prevent clotting or dissolve the clot could be disadvantageous too. Under such medication, if there is a wound or excessive bleeding, the bleeding will take longer to stop. If the wound occurs at any vital internal organ such as the brain, the patient could have paralysis or partial paralysis. Before deciding to use any of the three medications, doctors need to make sure it is called for and would be useful. Please also bear in mind that there may be higher chances of disadvantage than advantage in some patients.
Let me tell you more about antiplatelets because they are very interesting. They can prevent and cure several heart disease symptoms and side effects are minial. This type of medicine can be eaten or injected, but injected agents work much faster but of course they are more expensive too. The most common edible antiplatelet is aspirin.
Aspirin has been discovered for more than a hundred years by extracting from a type of plant (if you are an organic person, this is one of those useful herbs too). Initially, aspirin was used to cure headaches and it works wonderfully. Later on it was found that it could also treat pain in other parts such as joints and it could also minimize fever.
Modern-age doctors in the past used aspirin to treat pain and fever without knowing how it worked. Later there were lab tests that confirmed aspirin could act against a type of protein in the body that is involved in inflammation which triggers pain and fever.
Using aspirin to treat heart diseases first started when it was found that aspirin could act against inflammation and also platelet formation so it could help prevent clotting in the arteries. After that, aspirin was prescribed to heart disease patients (because it is cheap) who were at risk of getting acute coronary thrombosis. However, patients who take aspirin also have risk of bleeding in the digestive tract more than those who don’t.
Studies were then conducted on thousands of patients. They were divided into two groups – one taking aspirin and the other not. They were observed for several years and it was concluded that aspirin-taking patients risk acute coronary thrombosis less than patients who did not take aspirin.
However, aspirin-taking patients risked bleeding especially at the digestive tract because aspirin irritates the stomach and cause ulcers. From the same study, it was found that there are more advantages than disadvantages. Later, cardiologists advise taking baby aspirin to patients who could have coronary artery disease or myocardial infarction. The risk factors are male gender, age over 50, high blood pressure, high cholesterol level, smoking and diabetes.
Recently there has been a report that low dosage of aspirin could prevent tumor in the intestine from turning into cancer.
I had a patient who was about 70 years old. I had been taking care of him since he was 50 and there had never been any sign of narrowed artery. However, he had several risk factors such as high cholesterol level, diabetes and high blood pressure. Initially, I prescribed some baby aspirin as well as cholesterol lowering agent and blood pressure controlling pills. He strictly followed my advice and since he took a good care of his health, exercised regularly, watched his weight and ate healthy food, his glucose level and blood pressure were in check.
Just a few years ago, he asked to stop taking baby aspirin because he noticed rashes on both arms as if there was internal bleeding. The rashes came and went from time to time. He didn’t bump into anything so he supposed stop taking baby aspirin might help. I agreed and said he could stop. The result was the rashes decreased but did not altogether disappear. Such rashes are known as senile purpural which is common among elders with sensitive skin.
Earlier this year, this very same patient asked to take the baby aspirin again because his family had history of intestinal cancer and he’d read that aspirin could prevent it. For fear of the cancer, he wanted to prevent it with these pills.
He explained to me that he first stopped the baby aspirin because he wasn’t scared of dying from heart diseases since death usually happens out of the blue and is not all that painful. What’s up with that? But he thought that dying from cancer would not be a pleasant end. For this reason, I couldn’t agree more!!!
Prof Nithi Mahanonda is consultant cardiologist and interventionist, Perfect Heart Institute.
ข้อคิดเห็นทั้งหมดนี้เป็นความคิดเห็นส่วนบุคคลของผู้อ่าน ไม่เกี่ยวข้องกับเจ้าของเว็บไซต์แต่อย่างใด โปรดแสดงความเห็นด้วยความสุภาพ ถ้าเป็นครั้งแรกที่คุณโพสต์แสดงความเห็น อาจจะมีการคัดกรองเนื้อหาได้ การแสดงความคิดเห็นควรอยู่ในประเด็น ห้ามโจมตีใส่ร้ายบุคคลอื่น หรือทำลิงค์ไปยังเว็บไซต์ที่มีเนื้อหาไม่เกี่ยวข้องกัน ผู้ดูแลเว็บไซต์สามารถแก้ไขหรือลบความคิดเห็นได้ทุกกรณี
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