Blood flows ceaselessly through our bodies. In adults, it is five to six liters, transporting nutrients and oxygen to the last cell of the body, to name just one of the many tasks of the blood. However, it is just as vital for the organism that the blood stops flowing at the decisive moment. Otherwise, any injury, no matter how small, would lead to a dangerous hemorrhage. Hemostasis is the name given to the process by which bleeding stops.
Hemostasis: the normal procedure
Hemostasis is divided into two phases: Primary hemostasis and secondary hemostasis. Primary hemostasis is the body’s immediate response to an injury. Platelets, a regular component of blood, attach to the wound edges and form a plug-like closure. At the same time, the blood vessel contracts, blood flow is throttled, and thus less blood escapes. The time from the first drop of blood to the first closure of the injured area usually takes two to three minutes and is called the bleeding time. However, the closure by the platelets is not yet stable. Permanent, firm closure occurs via secondary hemostasis, and this is the term used to describe the activation of blood clotting. A large number of clotting factors are involved in this process. Like a series of dominoes in which one stone bumps into the next, here one clotting factor activates the next until finally an entire cascade has run its course and the defect is reliably closed with a stable clot until final repair.
Increased tendency to clot
Many people have a tendency to have increased clot formation. There are many causes, such as a change in the composition of the blood or a change in its flow rate. But a special role is played by changes in the vascular wall
- As a result of injury,
- As a result of inflammation,
- Or in the context of atherosclerosis.
The changes fatally activate hemostasis, and clot formation occurs in the blood vessel. This can lead to complete occlusion of the affected blood vessel, or carry the clot with the bloodstream to a distant blood vessel, such as in the brain or lungs with serious consequences for the organism.
Medications for blood clots
To prevent this, various medications are used when there is a tendency to blood clots. Once the platelet aggregation inhibitors (TAH), which are drugs that prevent the clumping of blood platelets, in technical language platelets, into a clot. Furthermore, anticoagulants, which are substances that interrupt the clotting cascade.
Platelet aggregation inhibitors
The best-known drug from this group is acetylsalicylic acid, or ASA. It prevents the formation of clots in the arteries in cases of atherosclerosis and is usually prescribed long-term after a heart attack or stroke. However, ASA does not prevent clots in the veins, which is why it is not suitable, for example, for preventing so-called “economy-class syndrome”, i.e. venous thrombosis, for example on long-haul flights. ASA can lead to gastritis, and even to gastric ulceration and gastric bleeding, which is why patients should consult their doctor if they experience symptoms such as acid regurgitation or diffuse discomfort in the stomach area. People with asthma may have an allergic reaction to ASA, so caution is also advised when taking it. The drug must not be taken by anyone who has already had a stomach ulcer, and it is also prohibited in the last third of pregnancy. Caution is advised if pain medication is also required, as this can weaken the effect of ASA. ASA taken at the same time as anticoagulants, on the other hand, can cause severe bleeding. And anyone taking ASA should make the attending physician aware of this before a planned surgical procedure, because there is an increased risk of bleeding when taking ASA. If it is safe to do so, ASA should be discontinued one week before the operation. This is because it takes that long for the effect to wear off. Other substances in this group have been used mainly as reserve agents, that is, only if a patient cannot tolerate ASA.
Anticoagulants for blood clots.
Of the drugs that interrupt the clotting cascade, coumarins are relevant outside the hospital setting.They reduce the risk of clot formation in the entire bloodstream, i.e. in both the arteries and the veins. They are used, for example, in patients following thrombosis of the veins in the leg, pulmonary embolism or a heart attack. A side effect can be intolerance, but also hair loss or liver inflammation. For this reason, liver patients, for example, must not be given coumarins. Anyone taking coumarins must be continuously monitored by a doctor. If coagulation is reduced too much, dangerous bleeding can occur. If, on the other hand, it is reduced too little, the effect may not be sufficient and a clot may form. For this reason, the so-called therapeutic range is regularly checked by taking a blood sample, after which the daily tablet intake is determined. Patients who have to take the drug on a long-term basis can learn in a training course how to determine their coagulation level and then adjust their tablet intake independently. In everyday life, coumarin patients must be aware that they bleed longer than other people when they are injured. However, blood clotting is not completely stopped, and for small wounds it is usually sufficient to press on the wound for a few minutes with a clean gauze compress or other suitable dressing material. For larger wounds, however, a physician should be consulted, who may administer a drug that will quickly restore clotting. Caution should also be exercised if bleeding occurs for no apparent reason, such as a nosebleed or blood in the stool.
Coumarins and diet
Incidentally, vitamin K raises coagulation when coumarin is taken. However, the effect sets in only slowly, which is why carrying medication with vitamin K as an antidote for emergencies does not make sense. However, vitamin K is also important because many foods contain large amounts of vitamin K, such as spinach and broccoli. Nevertheless, a coumarin patient does not have to give up these foods, they should just be eaten evenly throughout the week and not in large quantities. There are no other food restrictions either; there is no “coumarin diet.”
Special caution is needed in coumarin patients
When visiting a doctor, it should always be pointed out that coumarins are being taken. This is because even an injection into the muscle is not allowed in coumarin patients, and even the extraction of a tooth wants to be well planned. There are also a large number of medications that enhance or weaken the effect of coumarins, which is why additional medications should only be taken after consultation with the doctor. Very important: Anyone taking coumarins is given an ID card in which, among other things, the coagulation values and the tablet intake are noted. You should always carry this identification card with you!
Knowledge means safety
People who take anti-clotting medications often need them for the rest of their lives. However, this statement is not meant to discourage, but rather to provide the incentive to want to know as much as possible about the effects and side effects of “one’s” medication. Because the more you know about it, the more confident you become in dealing with it. And once you have the whole thing under control, there’s really nothing standing in the way of a fairly “normal” life.
