What are the potential downsides to the empiric use of Amicar (tranexamic acid) after cardiac surgery?

From the Guidelines

The empiric use of Amicar (tranexamic acid) after cardiac surgery can be associated with potential downsides, including seizures at higher dosages, and its use should be guided by a maximum total dose of 100 mg/kg to minimize risks. The use of tranexamic acid in cardiac surgery has been evaluated in several studies, with evidence suggesting its effectiveness in reducing bleeding and the need for transfusions 1. However, higher dosages of tranexamic acid have been associated with an increased risk of seizures 1.

Some key points to consider when using tranexamic acid in cardiac surgery include:

• The recommended maximum total dose of 100 mg/kg to minimize the risk of seizures 1
• The potential benefits of reduced bleeding and transfusion needs, which must be weighed against the potential risks of thrombotic complications and other adverse effects
• The importance of careful patient selection and monitoring to minimize risks and optimize outcomes

It is also worth noting that other antifibrinolytic agents, such as epsilon aminocaproic acid, may be considered as alternatives to tranexamic acid in certain situations 1. However, the choice of agent and dosing strategy should be guided by the most recent and highest-quality evidence, as well as careful consideration of the individual patient's needs and risk factors. In the context of cardiac surgery, the use of tranexamic acid has been recommended by some guidelines, including those from the Enhanced Recovery After Surgery (ERAS) society 1.

Overall, while the empiric use of Amicar (tranexamic acid) after cardiac surgery can be beneficial in reducing bleeding and transfusion needs, it is essential to be aware of the potential downsides and to use this agent judiciously, with careful consideration of the individual patient's risk factors and needs. The most recent and highest-quality study on this topic is from 2019, which provides guidance on the use of tranexamic acid in cardiac surgery 1.

From the FDA Drug Label

5 WARNINGS AND PRECAUTIONS

5.1 Thromboembolic Risk Tranexamic acid is contraindicated in patients with active intravascular clotting. Tranexamic acid is an antifibrinolytic and may increase the risk of thromboembolic events. Venous and arterial thrombosis or thromboembolism has been reported in patients treated with tranexamic acid Avoid concomitant use of tranexamic acid and medical products that are pro-thrombotic, as the risk of thrombosis may be increased.

5.3 Seizures Tranexamic acid may cause seizures, including focal and generalized seizures. The most common setting for tranexamic acid-induced seizures has been during cardiovascular surgery

5.4 Hypersensitivity Reactions Cases of hypersensitivity reactions, including anaphylactic reactions, have occurred with use of intravenous tranexamic acid.

5.5 Visual Disturbances Although not seen in humans, focal areas of retinal degeneration have been observed in cats and dogs following oral or intravenous tranexamic acid

5.6 Dizziness Tranexamic acid may cause dizziness.

The potential downsides to the empiric use of Amicar (tranexamic acid) after cardiac surgery include:

• Thromboembolic risk: increased risk of venous and arterial thrombosis or thromboembolism 2
• Seizures: risk of seizures, including focal and generalized seizures, particularly during cardiovascular surgery 2
• Hypersensitivity reactions: risk of hypersensitivity reactions, including anaphylactic reactions 2
• Visual disturbances: potential risk of visual disturbances, although not seen in humans 2
• Dizziness: risk of dizziness, which may be worsened by concomitant use of other drugs that cause dizziness 2

From the Research

Potential Downsides to Empiric Use of Amicar (Tranexamic Acid) after Cardiac Surgery

• The empiric use of tranexamic acid after cardiac surgery may be associated with several potential downsides, including:
  • Seizures: Studies have reported an increased risk of seizures with the use of tranexamic acid, particularly in patients with advanced age, underlying neurologic disease, or chronic kidney disease 3, 4, 5.
  • Thrombotic adverse effects: Although tranexamic acid has been shown to reduce blood loss and transfusion requirements, it may also increase the risk of thrombotic complications, such as deep vein thrombosis or pulmonary embolism 3, 6.
  • Renal injury or failure: Tranexamic acid may be associated with an increased risk of renal injury or failure, particularly in patients with pre-existing kidney disease 5.
  • Low cardiac output syndrome: The use of tranexamic acid may also be associated with an increased risk of low cardiac output syndrome, although the evidence is limited 5.
  • Vascular thrombosis: Tranexamic acid may increase the risk of vascular thrombosis, although the evidence is limited 5.
• Dosage considerations:
  • High doses of tranexamic acid may increase the risk of adverse effects, such as seizures 4.
  • Patients with chronic kidney dysfunction may require reduced dosing regimens due to reduced clearance and drug accumulation 4.

Key Findings

• A systematic review and meta-analysis found that tranexamic acid is effective in reducing blood loss and transfusion requirements in cardiac surgery, but may be associated with an increased risk of seizures and other adverse effects 3.
• A study comparing tranexamic acid with ɛ-aminocaproic acid in pediatric cardiac surgery found no significant difference in blood loss or adverse effects, although the risk of seizures was higher with tranexamic acid 5.
• A prospective, randomized, double-blind, placebo-controlled study found that continuation of tranexamic acid administration after cardiac surgery did not provide additional benefits in reducing bleeding or improving outcomes, and may increase the risk of procoagulant response 6.