Drug thrombosis prophylaxis
The following drugs are used for thrombosis prophylaxis:
- Heparin
- Pentasaccharide Fondaparinux (Arixtra®)
- Acetylsalicylic acid
- Oral anticoagulants
- Thrombin inhibitors
Note
General information on the topic of thrombosis prophylaxis can be found on the start page on the topic: Thrombosis prophylaxis
Heparins
The first large group of anticoagulant Drugs for thromboembolism prophylaxis are the heparins.
They are used for prevention in surgical interventions as well as in conservative medicine. It can also be used for pre-existing venous thrombosis or pulmonary embolism.
Important!
Its immediate effect is ideal.
Mechanism of action and indication
Heparin is a natural anticoagulant that occurs naturally in certain cells. These cells are basophilic granulocytes and mast cells. It binds to an anticoagulant in the body called Antihrombin, forms a complex with it and thus increases its effectiveness. Various factors in the coagulation cascade are thereby inhibited and the formation of thrombi is prevented or the lysis of thrombin (enzyme of the blood coagulation cascade) is initiated.
Classification
The heparins are divided into unfractionated heparins (UFH) and low molecular weight heparins (LMWH). Low molecular weight fractionated heparins are more preferred nowadays because they have better bioavailability and longer duration of action compared to unfractionated heparins.
examples for unfractionated heparin are e.g .:
- Liquemin®,
- Calciparin®
examples for low molecular weight, fractionated heparins are e.g .:
- Clexane®,
- Mono-Emolex®,
- Fragmin®,
- Innohep®
application
Heparins are either under Bypassing the Gastrointestinal tract (parenterally, i.e. venous) or under the skin (subcutaneous) with a syringe. During pregnancy, the heparin cannot affect the embryo via the bloodstream, so it does not cross the placenta.
Side effects
In consequence of Overdose there may be intra- or postoperative bleeding. The heparins as drug are obtained from animals (pork, beef), making it too allergic reactions can come.The blood platelets can also be influenced and, as a result, their number is too low (thrombocytopenia). If taken for a long time it can cause Bone loss come. Reversible, on the other hand, is possible Hair loss.
Interaction with other drugs
An interaction can be with Medication occur, which inhibit the function of the blood platelets, so-called platelet aggregation inhibitors, so that the risk of bleeding is increased.
The effect of heparin, on the other hand, is inhibited by its interaction with drugs such as certain drugs
- Antibiotics (Tetracyclines),
- Medicines for allergies (antihistamines),
- Heart medications (cardiac glycosides).
Laboratory supervision
The following laboratory parameters should be checked regularly during heparin therapy:
- aPTT, thrombin time in therapy with unfractionated heparin
- if necessary anti-Xa test in therapy with low molecular weight heparin
Further information
Read more on the subject on the following page: Heparin Induced Thrombocytopenia (HIT)
Pentasaccharide Fondaparinux / Arixtra®
The pentasaccharide fondaparinux (Arixtra®) is a synthetically produced sugar that is produced by antithrombin (a naturally occurring blood coagulation inhibitor) Factor Xa inhibits the coagulation cascade.
The drug is administered by giving it under the skin (subcutaneous, s.c.). When absorbed into the bloodstream, it binds to antithrombin. The substance is excreted via the Kidneys. The drug is applied no earlier than six hours after an operation.
A cross reaction with HIT type II-Antibodies could so far not determined become.
More to Arixtra® can be found under our topic: Arixtra®
indication
This drug is approved for patients with high-risk orthopedic and trauma surgery profiles.
Important!
Since the substance is excreted by the kidneys, the drug should not be given to patients with severe renal insufficiency.
Acetylsalicylic acid
Acetylsalicylic acid is also known under the name ASA or Aspirin ®.
Its function is to disrupt blood platelet function (anti-platelet agents). A single administration of ASA is recommended for the prophylaxis of a thrombus, especially of the deep leg veins, insufficient.
Oral anticoagulants
Oral anti-coagulants include the vitamin K antagonists, such as the Marcumar®. Vitamin K is an important cofactor of enzymes that initiate and regulate the blood coagulation cascade. The onset of action is delayed. It is mainly used as long-term prophylaxis.
Read more on the topic: Xarelto®
Laboratory supervision
The following laboratory parameters must be checked regularly:
- Quick value / thromboplastin time TPZ
- INR
As a measure of the extrinic pathway of the blood coagulation cascade, the Quick value or the thromboplastin time TPZ describes the time until coagulation.
Nowadays the Quick value is increasingly being replaced by the INR value (International Normalized Ratio), an international standardization of the Quick value. The INR should be between 2.0 and 3.0 for optimal protection.
Thrombin inhibitors
Thrombin is factor II of the blood coagulation cascade and splits as Enzyme the precursor fibrinogen to fibrin (factor I of the coagulation cascade), which then ultimately forms the blood clot (white thrombus). It also activates other coagulation factors.
The thrombin inhibitor Hirudin shows no cross-reactions with HIT type II antibodies, so that the active ingredient is used primarily for thromboembolism prophylaxis in patients with known HIT type II.
Homeopathic remedies
Homeopathic remedies are true not for the sole prophylaxis of thrombosis suitable, but can be used with low risk factors additionally before and after operations help to reduce the risk of thrombosis.
Suitable means are, among others Lachesis, buckeye and Witch hazel (Witch hazel).
You can read more information on this topic here: Homeopathy before operations
