Anticoagulants, blood thinners, also known in medicine as anticoagulation, counteract blood clotting. The drugs are used in the prevention of vascular occlusions. Various anticoagulants are also equally suitable for dissolving blood clots.
What are anticoagulants?
Anticoagulants are a group of medications that prevent blood from clumping together by decreasing its “clotting process.” Anticoagulants are a group of drugs that prevent blood from clumping by decreasing this “clotting process.” Based on the two different mechanisms of action, two technical terms for anticoagulants are in common use accordingly:
1) Anticoagulants: the effect is on proteins in the liquid
blood (blood plasma)
2) Platelet aggregation inhibitors: The effect takes place on the surface of the
surface of the blood platelets (thrombocytes).
Some scientists reject the conceptual separation of the two classes and regard the platelet aggregation inhibitors only as a subgroup of the anticoagulants. This makes sense because the resulting effect is the same: both ultimately prevent the formation of blood clots (“thrombi”) in the vessels. This is why the term “blood thinner” is commonly used. Although this term is not quite correct, it always means the same as the term anticoagulant.
Application, effect and use
Anticoagulants are largely used in the prevention of various circulatory diseases. The medication is intended to prevent the formation of thrombi and emboli (vascular occlusions) in patients at risk. The focus is on heart attacks and strokes as well as pulmonary embolisms. The group at risk includes people with arteriosclerosis, because the vascular deposits can trigger blood clotting. A second indication is cardiac arrhythmias, especially atrial fibrillation. The tendency to clot in this clinical picture results from a “blood lake” in the atria. Strokes are more likely to occur without the use of anticoagulants. Furthermore, angina pectoris is an area of application for anticoagulants, which must also be given following a survived myocardial infarction. People with a genetically increased tendency to clot should also take anticoagulants. Anticoagulants are also mandatory medication after operations if patients are bedridden for a longer period of time. Heparins are anticoagulants that can even be used to dissolve an acute thrombus. These drugs are an important emergency intervention for myocardial infarction and other emboli as well as vasoconstriction. Heparins can only be administered as an infusion. Blood clotting must also be prevented in blood units or in blood samples. Furthermore, the apparative treatment of the blood requires countermeasures against thrombus formation. This concerns blood washing (dialysis) and the “extracorporeal circuit” (heart–lung machine). Indispensable here is also the use of anticoagulants.
Herbal, natural, and pharmaceutical anticoagulants.
Anticoagulants target different points in the clotting process. Coagulation (blood clotting) is a complex biochemical chain reaction involving several proteins as well as vitamin K and calcium. Coumarins are plant-derived agents that block the effect of vitamin K. This group of anticoagulants includes the well-known Marcumar, whose model is an ingredient of woodruff and is produced synthetically in a modified form. Other anticoagulants bind calcium and thus interrupt the chain reaction of blood clotting. These include, for example, citrate (salt of citric acid), which is used in dialysis. Some anticoagulants are active substances from animal metabolism. Hirudin used to be obtained from leeches (“hirudo”), but is now produced by genetic engineering. Doctors apply the protein parenterally (infusion); the effect is to block the clotting factor thrombin. Heparins cannot be absorbed by the intestine either, so here too the only option is administration by injection or infusion. Pharmaceutical manufacturers still obtain the sugar-like substances from pig intestines. Heparins block various clotting factors from the antithrombin group. Other fully synthetic anticoagulants influence other plasma factors involved in blood clotting. The platelet aggregation inhibitors include aspirin.The drug prevents platelets from sticking together and is based on a model in the plant kingdom. Salicin is a substance found in willow bark (Salix: Latin: “willow”). The synthetically produced preparations contain acetylsalicylic acid and are also anticoagulants.
Risks and side effects
Anticoagulants also suppress physiologically important wound closure. Even the smallest injuries therefore carry the risk of bleeding that is difficult to stop, and this effect is particularly critical in accidents. Because of the risk of bleeding, anticoagulants must be discontinued before surgery. On the other hand, overdoses can lead to internal bleeding. Coumarins have a weak liver-damaging effect, while heparins can decrease platelet formation. Aspirin is responsible for gastric ulcers and even gastric perforations when used in excess. Kidney and liver damage are also a possible consequence of the medication. Rare side effects are numerous across the anticoagulant spectrum and are reflected in anticoagulant package inserts.
