Modern medicine covers the treatment of thousands of disease entities. Unfortunately, in some cases, no causal treatment is known or simply not possible due to the specific nature of the disease. Therefore, various forms of prophylaxis are sometimes used in order to reduce the risk of a dangerous disease as much as possible. One of the most common forms of such prophylaxis is so-called anticoagulant treatment, which involves giving patients appropriate medication to prevent the formation of clots and embolisms.
Anticoagulant treatment with heparins
Heparins are a group of drugs characterised by very high efficacy in the prevention of venous thromboembolism. The main indications for the use of heparins are:
- prevention of venous thromboembolism in people after orthopaedic and surgical procedures who have to remain immobile due to their general condition,
- prevention of thrombus formation during haemodialysis in patients with extreme renal failure,
- prevention of thromboembolic complications in pregnant or postpartum patients (heparins do not harm the foetus).
Crucially, heparins are a relatively safe drug. There are two main types of heparins currently in use: low- and low-molecular-weight heparins. The former are relatively old drugs, but have the great advantage of being able to control anticoagulant treatment by determining the APTT (kaolin- kefalin time) value. Measurements of its values allow assessment of whether the doses of the administered drug are too high, which could lead to dangerous haemorrhagic complications. If too high a dose of low-molecular-weight heparins is administered, protamine sulphate is the drug that reverses their effect. Low-molecular-weight heparins are a new generation of drugs. They are characterised by a much lower incidence of serious complications. However, it is not always possible to control the treatment process with them.
Treatment with vitamin K antagonists
Vitamin K antagonists are a group of drugs that inhibit the production of clotting factors in the liver. As the name suggests, these factors are produced using vitamin K. Preparations such as acenocoumarol or warfarin prevent the production of biologically active clotting factors. However, it is extremely important to note that they do not inactivate the factors already formed. Therefore, the effect of these drugs begins approximately three days after the first dose. During this period, previously produced procoagulant factors are used up and their overall pool decreases due to inhibition of production in the liver. The main indication for initiating treatment with either acenocoumarol or warfarin is the occurrence of an episode of thromboembolic disease. In the absence of contraindications to treatment with them, the standard is to administer the drugs for a minimum of three months (the duration of their use depends on the cause of the venous thromboembolism). Other indications for acenocoumarol/warfarin include:
- cardiac arrhythmias - most commonly atrial fibrillation - the administration of the drugs is intended to reduce the risk of dangerous clots forming in the heart that could lead to embolisms,
- antiphospholipid syndrome - this is a dangerous autoimmune disease that causes microemboli in the brain, for example. The administration of acenocoumarol/warfarin is aimed at avoiding complications such as stroke,
- artificial valves - if artificial heart valves have to be implanted, the patient undergoing this procedure will be obliged to use vitamin K antagonists for the rest of his or her life. The drugs are designed to prevent the formation of clots on the artificial valves.
If vitamin K antagonists are used, it is essential to monitor the treatment by having the INR measured regularly (once a month, once a week at the beginning of treatment). It should be between 2-3 for patients treated with acenocoumarol/warfarin.
