Anticoagulants are a class of drugs that reduce the clotting ability of your blood. These medications have the ability to either dissolve existing clots or prevent the formation of new ones. The presence of blood clots can lead to serious medical conditions like strokes, heart attacks, and pulmonary embolisms. Anticoagulants play a crucial role in preventing and treating these life-threatening conditions.

These medications are available in various forms, including injections, intravenous (IV) medications, and oral formulations. They are commonly used to manage and mitigate the risk of pulmonary emboli, heart attacks, strokes, and other potentially fatal outcomes associated with blood clot formation.

Reasons for undergoing the procedure

Blood clots form at the location of an injury that has to be repaired and stay there when they function as they should. They can be quite harmful if they form in the bloodstream or don’t stay in one spot. An overly large clot has the potential to get stuck in a smaller blood vessel. The small blood vessel may obstruct the blood flow that one of the organs requires to survive if it is at a vital area.

Blood clot blockages can result in the following deadly outcomes:

  • Pulmonary embolism (PE): This happens when a blood clot gets stuck in an artery supplying the lungs. A pulmonary embolism may be fatal if the obstruction is sufficiently severe.
  • Myocardial infarction (heart attack): These happen when blockages develop in the arteries supplying blood to the heart. These have the potential to be life threatening.
  • Stroke: If a blood clot makes its way up to the brain, it can easily become lodged in the small blood vessels, making it extremely dangerous.

Individuals who have medical conditions or diseases that elevate their susceptibility to the clot-related events mentioned earlier can find advantages in using anticoagulant medications.

Among these conditions are:

  • Atrial fibrillation: The upper chambers of the heart are experiencing an abnormal cardiac rhythm. Blood can pool when there is fibrillation because the heart’s upper chambers are beating too quickly for the heart to pump blood efficiently. Blood can clot when it pools, and clots can go from the heart to the brain, which can result in a stroke.
  • Heart valve replacement or surgery: There is a higher chance that clots will form at the location of the new valve in certain heart valve replacements. Anticoagulants prevent blood clots from forming.
  • Knee and hip replacement: The risk of clots developing in leg veins can be increased by joint replacements. One of the main conditions that lead to pulmonary embolism is deep vein thrombosis.
  • Blood clotting disorders: Conditions and diseases that impact blood clotting are include. It is possible for someone to inherit specific medical conditions from their parents or pass them on to their children because they are hereditary in nature.


The primary concern when it comes to adverse effects associated with anticoagulants is bleeding, which is the most common risk. However, depending on the specific medication, there may be other potential risks to consider.

  • Warfarin: Because the dosage of warfarin needs to be exact, there is a considerably higher chance of bleeding. The following are additional risks and adverse effects.
    • Blue or purple toe: Your toes and feet exhibit a noticeable alteration in color, particularly evident on the soles of your feet or along the sides of your toes. The problem typically appears a few weeks to two months after starting warfarin and can be painful at times.
    • Skin necrosis: Warfarin can occasionally lead to clots forming in the blood vessels in the arms and legs or in fatty areas such as the breasts, thighs, or buttocks. These clots block blood flow, which results in skin death in the affected areas. Those with problems in specific blood proteins deficiencies—which are frequently inherited—are most likely to experience this. Although it can occur up to 10 days after the patient begins taking warfarin, it typically manifests five days after the medication is started.
    • Congenital disabilities or miscarriages: Warfarin shouldn’t be taken when pregnant because it can harm an embryo or fetus. However, as warfarin cannot be transferred through breast milk, it is safe to take while nursing.
    • Patients with lupus complications: People with lupus or comparable illnesses typically require greater doses of warfarin. Before a medical treatment, people with lupus frequently need to stop taking it and switch to other medication in order to prevent bleeding issues.
  • Heparin: Heparin has mild to severe adverse effects that can harm bones and other blood components.
    • Heparin-induced thrombocytopenia (HIT): This has two types:
      • Type I: The type of blood cell known as platelets, which are essential to blood clotting, are somewhat reduced as a result of this type of HIT. About 10% of individuals taking heparin or its derivatives experience this more frequent type of HIT. It normally goes away a week after people stop using heparin, and it’s not thought to be dangerous.
      • Type II: This particular type of HIT occurs when heparin sets off an immune system reaction that activates platelets, which are blood cells that form clot, starting a chain reaction of clotting. Because it can lead to systemic clotting throughout the body, this kind of HIT is quite harmful. It also happens very rarely, as just 1% of heparin recipients experience it (unfractionated heparin is more likely to cause it than low-molecular-weight heparin).

      Severe or long-lasting problems are a common side effect of HIT. That’s why anyone taking unfractionated or low-molecular-weight heparin needs to have their platelet levels monitored. A healthcare provider will stop administering heparin (in either of those two types) right away and switch to another medicine if they have any suspicions about HIT.

    • Osteoporosis: Usually, this problem only arises when heparin is used for an extended period of time (more than one month). The reason for this is that heparin slows down the production of new bone cells and speeds up the body’s normal process of breaking down existing bone cells. With LMWH heparin, that is less likely to occur.
  • Direct oral anticoagulants: Oral anticoagulants can occasionally result in bleeding or indigestion in the gastrointestinal system.


The body constantly maintains a delicate equilibrium between its clotting and anti-clotting functions. When an injury occurs, inadequate clotting can result in significant blood loss or even potential fatality. Conversely, excessive clotting can lead to the harmful medical events mentioned earlier. Specific components within the blood regulate the clotting mechanisms, ensuring they remain inactive until necessary for healing an injury. This intricate balancing act during the clotting process generally serves a beneficial purpose. It not only stops bleeding but also creates a protective barrier to prevent debris and bacteria from entering the wound. Subsequently, it regenerates the skin, restoring it to its original condition.

Anticoagulants function by interfering the regular mechanisms involved in clotting. They stop or reverse the process of coagulation, which is the solidification of blood to create a clot. The method that an anticoagulant affects the clotting process varies depending on its kind.

Intravenous and injectable medications

  • Heparin and its derivatives: Heparin works by triggering the body’s anti-clotting mechanisms to prevent blood from clotting. A blood protein known as antithrombin is used in one of the anticlotting mechanisms. Antithrombin prevents other components of the clotting process from functioning normally when heparin activates it.
    There are two types of heparin, and there is also a closely related third medication:

    • Unfractionated heparin (UFH): Unfractionated heparin is more potent and acts quickly. This is due to the fact that UFH is a longer molecule, meaning it is long enough to wrap around both antithrombin and thrombin, a protein that encourages clotting, binding them together. This further inhibits clotting by neutralizing both proteins. UFH also requires ongoing lab testing monitoring. This is due to the fact that the dosage determines its efficiency, and the required dosage varies greatly across individuals. Too much will increase the chance of bleeding, while too little won’t effectively prevent clotting.
    • Low-molecular-weight heparin (LMWH): Because low-molecular-weight heparin’s molecules are shorter, it can only bind to antithrombin. This implies that LMWH doesn’t require the close monitoring necessary with UFH and that the effects are more predictable and long-lasting.
    • Fondaparinux: Fondaparinux is a synthetic drug that functions in a manner akin to heparin. Similar to heparin, fondaparinux triggers antithrombin activation, but its effects are prolonged over an extended period. Since it isn’t as potent as UFH or LMWH, it’s usually taken to avoid clots rather than cure existing ones.
  • Direct thrombin inhibitors: When thrombin binds to a thrombin inhibitor, it prevents thrombin from helping in the clotting process. Particularly to prevent clots from forming following specific medical operations, they are frequently employed as substitutes for heparin and its equivalents. Among them are bivalirudin, desirudin, and argatroban.

Oral medications

  • Warfarin (vitamin K antagonist): Warfarin inhibits the usage of vitamin K, an essential component in the clotting process, as it is a vitamin K antagonist. Warfarin’s requirement for cautious dosage and frequent lab testing in order to minimize problems as one of its main disadvantages. There may be serious bleeding if the dosage is not administered precisely.
    There are situations where certain medical conditions require warfarin to be the only anticoagulant treatment choice available. These include diseases affecting the heart’s mitral valve, having a mechanical heart valve, and end-stage renal disease. The choice of anticoagulant medication is carefully considered in light of the patient’s unique medical needs.
  • Direct oral anticoagulants: When warfarin is not an option, these drugs are frequently utilized and can all be taken on a regular basis without requiring routine lab tests. A medication that works similarly to the IV thrombin inhibitors previously mentioned is dabigatran, a thrombin inhibitor. Other medications, such as apixaban, edoxaban, and betrixaban, inhibit factor Xa (10-A), a crucial clotting factor.


Anticoagulants have proven to be highly effective in preventing life-threatening conditions such as heart attacks, pulmonary embolisms, and strokes. Moreover, there is a wide array of mechanisms through which these medications operate, offering flexibility for those who cannot take one specific drug to potentially find an alternative that suits their needs.

The duration of anticoagulant therapy depends on the type of medication and its administration method. Injectable and intravenous (IV) anticoagulants are generally not intended for prolonged use. Conversely, oral anticoagulants can often be taken for extended periods, subject to the guidance and prescription of their healthcare provider, who will determine the appropriate duration for each patient.

If a patient experiences any mild to severe bleeding symptoms, they should contact their healthcare provider. Among them are:

  • Uncontrollably bleeding from wounds and scrapes, the nose, or the gums.
  • Having unusual fatigue, weakness, or dizziness.
  • Developing bruises more frequently or discovering them unexpectedly and being unable to recall how they occurred.

Individuals who use blood thinners are additionally susceptible to serious bleeding after injuries, particularly internal bleeding. If a patient experiences any of the following symptoms, they should see the healthcare provider right away:

  • Any type of fall in which they make contact with the ground or an object, even if they are not injured or bleeding. Anticoagulant users are more likely to experience internal bleeding from falls and injuries, particularly in the brain. This also applies if they are struck in the head by something, even if it doesn’t knock them down.
  • Experiencing a car accident or getting hit by any form of object thatresults in a significant bruise.
  • Vomiting up or coughing up blood, particularly vomit that resembles coffee grounds.
  • Bleeding in the stool (red or tar-like excrement) or urine (orange, red, or brown pee).
  • Pain in the stomach or headache, particularly if it is sudden, intense, or both.