Anticoagulants, commonly referred to as blood
thinners, are chemical substances that prevent or reduce coagulation of blood,
prolonging the clotting time. Some of them occur naturally in blood-eating
animals such as leeches and mosquitoes, where they help keep the bite area
unclotted long enough for the animal to obtain some blood. As a class of medications,
anticoagulants are used in therapy for thrombotic disorders. Oral
anticoagulants (OACs) are taken by many people in pill or tablet form, and
various intravenous anticoagulant dosage forms are used in hospitals. Some
anticoagulants are used in medical equipment, such as test tubes, blood
transfusion bags, and dialysis equipment.
Anticoagulants are closely related to antiplatelet drugs and thrombolytic drugs by manipulating the various pathways of blood coagulation. Specifically, antiplatelet drugs inhibit platelet aggregation (clumping together), whereas anticoagulants inhibit the coagulation cascade by clotting factors that happens after the initial platelet aggregation.
Common anticoagulants include warfarin and heparin.
Medical Uses
The use of anticoagulants is a decision based upon the risks and benefits of anticoagulation. The biggest risk of anticoagulation therapy is the increased risk of bleeding. In otherwise healthy people, the increased risk of bleeding is minimal, but those who have had recent surgery, cerebral aneurysms, and other conditions may have too great of risk of bleeding. Generally, the benefit of anticoagulation is prevention of or reduction of progression of a disease. Some indications for anticoagulant therapy that are known to have benefit from therapy include:
In these cases, anticoagulation therapy can prevent formation of dangerous clots or prevent growth of clots.
The decision to begin therapeutic anticoagulation often involves the use of multiple bleeding risk predictable outcome tools as non-invasive pre-test stratifications due to the potential for bleeds while on blood thinning agents. Among these tools are HAS-BLED, ATRIA, and CHA2DS2-VASc.
Adverse effects
Patients aged 80 years or more may be especially susceptible to bleeding complications, with a rate of 13 bleeds per 100 person-years. Depletion of vitamin K by coumadin therapy increases risk of arterial calcification and heart valve calcification, especially if too much vitamin D is present. In a meta-analysis studying the effects of warfarin use in patients with end stage renal disease and atrial fibrillation, there was no increased risk of stroke incidence with warfarin use, but there was a significantly increased risk of all-cause bleeding, compared to alternate treatments (aspirin, dabigatran, rivaroxaban) or no warfarin use. Although poor adherence to anticoagulation therapy is associated with a higher risk of stroke among high-risk patients (i.e. those with a CHA2DS2‐VASc score ≥2), the benefits of anticoagulation therapy may not outweigh the harms in patients with CHA2DS2‐VASc score 0 or 1.
Interactions
Foods and food supplements with blood-thinning effects include nattokinase, lumbrokinase, beer, bilberry, celery, cranberries, fish oil, garlic, ginger, ginkgo, ginseng, green tea, horse chestnut, licorice, niacin, onion, papaya, pomegranate, red clover, soybean, St. John's wort, turmeric, wheatgrass, and willow bark. Many herbal supplements have blood-thinning properties, such as danshen and feverfew. Multivitamins that do not interact with clotting are available for patients on anticoagulants.
However, some foods and supplements encourage clotting. These include alfalfa, avocado, cat's claw, coenzyme Q10, and dark leafy greens such as spinach. Their intake should be avoided whilst taking anticoagulants or, if coagulability is being monitored, their intake should be kept approximately constant so that anticoagulant dosage can be maintained at a level high enough to counteract this effect without fluctuations in coagulability.
Grapefruit interferes with some anticoagulant drugs, increasing the amount of time it takes for them to be metabolized out of the body, and so should be eaten only with caution when on anticoagulant drugs.
Anticoagulants are often used to treat acute deep vein thrombosis. People using anticoagulants to treat this condition should avoid using bed rest as a complementary treatment because there are clinical benefits to continuing to walk and remaining mobile while using anticoagulants in this way. Bed rest while using anticoagulants can harm patients in circumstances in which it is not medically necessary.
Types
A number of anticoagulants are available. The traditional ones (warfarin, other coumarins and heparins) are in widespread use, which are commonly known as vitamin K anticoagulants/vitamin K antagonist; since the 2000s a number of new agents have been introduced that are collectively referred to as the novel oral anticoagulants (NOACs) or directly acting oral anticoagulants (DOACs)/Non vitamin K antagonist oral anticoagulants. These agents include direct thrombin inhibitor(dabigatran) and factor Xa inhibitor (rivaroxaban, apixaban and edoxaban) and they have been shown to be as good or possibly better than the coumarins with less serious side effects. The newer anticoagulants (NOACs/DOACs), are more expensive than the traditional ones and should be used with care in patients with kidney problems. Additionally, there is no antidote for the factor Xa inhibitors, so it is difficult to stop their effects in the body in cases of emergency (accidents, urgent surgery). Idarucizumab was FDA approved for the reversal of dabigatran in 2015.
https://en.wikipedia.org/wiki/Anticoagulant
Anticoagulants are closely related to antiplatelet drugs and thrombolytic drugs by manipulating the various pathways of blood coagulation. Specifically, antiplatelet drugs inhibit platelet aggregation (clumping together), whereas anticoagulants inhibit the coagulation cascade by clotting factors that happens after the initial platelet aggregation.
Common anticoagulants include warfarin and heparin.
Medical Uses
The use of anticoagulants is a decision based upon the risks and benefits of anticoagulation. The biggest risk of anticoagulation therapy is the increased risk of bleeding. In otherwise healthy people, the increased risk of bleeding is minimal, but those who have had recent surgery, cerebral aneurysms, and other conditions may have too great of risk of bleeding. Generally, the benefit of anticoagulation is prevention of or reduction of progression of a disease. Some indications for anticoagulant therapy that are known to have benefit from therapy include:
- Atrial fibrillation — commonly forms an atrial
appendage clot
- Coronary artery disease
- Deep vein thrombosis — can lead to pulmonary
embolism
- Ischemic stroke
- Hypercoagulable states (e.g., Factor V Leiden)
— can lead to deep vein thrombosis
- Myocardial infarction
- Pulmonary embolism
- Restenosis from stents
In these cases, anticoagulation therapy can prevent formation of dangerous clots or prevent growth of clots.
The decision to begin therapeutic anticoagulation often involves the use of multiple bleeding risk predictable outcome tools as non-invasive pre-test stratifications due to the potential for bleeds while on blood thinning agents. Among these tools are HAS-BLED, ATRIA, and CHA2DS2-VASc.
Adverse effects
Patients aged 80 years or more may be especially susceptible to bleeding complications, with a rate of 13 bleeds per 100 person-years. Depletion of vitamin K by coumadin therapy increases risk of arterial calcification and heart valve calcification, especially if too much vitamin D is present. In a meta-analysis studying the effects of warfarin use in patients with end stage renal disease and atrial fibrillation, there was no increased risk of stroke incidence with warfarin use, but there was a significantly increased risk of all-cause bleeding, compared to alternate treatments (aspirin, dabigatran, rivaroxaban) or no warfarin use. Although poor adherence to anticoagulation therapy is associated with a higher risk of stroke among high-risk patients (i.e. those with a CHA2DS2‐VASc score ≥2), the benefits of anticoagulation therapy may not outweigh the harms in patients with CHA2DS2‐VASc score 0 or 1.
Interactions
Foods and food supplements with blood-thinning effects include nattokinase, lumbrokinase, beer, bilberry, celery, cranberries, fish oil, garlic, ginger, ginkgo, ginseng, green tea, horse chestnut, licorice, niacin, onion, papaya, pomegranate, red clover, soybean, St. John's wort, turmeric, wheatgrass, and willow bark. Many herbal supplements have blood-thinning properties, such as danshen and feverfew. Multivitamins that do not interact with clotting are available for patients on anticoagulants.
However, some foods and supplements encourage clotting. These include alfalfa, avocado, cat's claw, coenzyme Q10, and dark leafy greens such as spinach. Their intake should be avoided whilst taking anticoagulants or, if coagulability is being monitored, their intake should be kept approximately constant so that anticoagulant dosage can be maintained at a level high enough to counteract this effect without fluctuations in coagulability.
Grapefruit interferes with some anticoagulant drugs, increasing the amount of time it takes for them to be metabolized out of the body, and so should be eaten only with caution when on anticoagulant drugs.
Anticoagulants are often used to treat acute deep vein thrombosis. People using anticoagulants to treat this condition should avoid using bed rest as a complementary treatment because there are clinical benefits to continuing to walk and remaining mobile while using anticoagulants in this way. Bed rest while using anticoagulants can harm patients in circumstances in which it is not medically necessary.
Types
A number of anticoagulants are available. The traditional ones (warfarin, other coumarins and heparins) are in widespread use, which are commonly known as vitamin K anticoagulants/vitamin K antagonist; since the 2000s a number of new agents have been introduced that are collectively referred to as the novel oral anticoagulants (NOACs) or directly acting oral anticoagulants (DOACs)/Non vitamin K antagonist oral anticoagulants. These agents include direct thrombin inhibitor(dabigatran) and factor Xa inhibitor (rivaroxaban, apixaban and edoxaban) and they have been shown to be as good or possibly better than the coumarins with less serious side effects. The newer anticoagulants (NOACs/DOACs), are more expensive than the traditional ones and should be used with care in patients with kidney problems. Additionally, there is no antidote for the factor Xa inhibitors, so it is difficult to stop their effects in the body in cases of emergency (accidents, urgent surgery). Idarucizumab was FDA approved for the reversal of dabigatran in 2015.
https://en.wikipedia.org/wiki/Anticoagulant
No comments:
Post a Comment