From the Guidelines
Tranexamic acid should be used with caution in patients with macroscopic hematuria due to the potential risk of ureteral thrombi formation, although recent studies have not demonstrated a significant increase in thrombotic risk with its use 1. The mechanism of action of tranexamic acid, an antifibrinolytic agent, involves inhibiting the breakdown of blood clots, which could theoretically lead to clot formation in the urinary tract when blood is already present. In the context of macroscopic hematuria, the presence of blood in the urinary tract may increase the risk of clot formation, potentially causing ureteral obstruction, severe pain, and kidney damage. However, a recent study published in 2021 in the journal Blood found that although there are theoretical thrombotic risks associated with antifibrinolytic therapies like tranexamic acid, randomized studies did not demonstrate an increased thrombotic risk in patients treated with tranexamic acid 1. Some key points to consider when evaluating the risk of ureteral thrombi with tranexamic acid in patients with macroscopic hematuria include:
- The cumulative risk of indefinite daily use of antifibrinolytic therapy is still a concern, despite reassuring data from recent retrospective studies 1
- Alternative approaches to managing hematuria, such as treating the underlying cause, ensuring adequate hydration, and considering other hemostatic measures, should be considered before initiating tranexamic acid therapy
- Close urological supervision and careful monitoring for signs of urinary obstruction, such as flank pain or decreased urine output, are essential if tranexamic acid is used in patients with macroscopic hematuria. The benefit of preventing blood loss with tranexamic acid must be carefully weighed against the potential risk of urinary tract obstruction in these patients, and the decision to use this medication should be made on a case-by-case basis, taking into account the individual patient's risk factors and clinical circumstances.
From the Research
Risk of Ureteral Thrombi with Tranexamic Acid (TXA)
- The use of tranexamic acid (TXA) in patients with macroscopic hematuria may pose a risk of ureteral thrombi, as reported in several studies 2, 3, 4.
- A study published in 2011 reported that chronic renal impairment is considered a relative contraindication to the use of TXA due to reports of ureteric clots and acute renal failure from cortical necrosis 2.
- Another study published in 1995 presented three clinical cases with microscopic haematuria, in whom TXA caused problems of clot formation in the urinary tract, indicating that microscopic haematuria should also be considered as a contraindication for TXA 3.
- A case report published in 2022 described a patient who developed upper urinary tract perforation secondary to TXA-induced ureteric clot obstruction, highlighting the risk of ureteric clot obstruction and upper urinary tract perforation with TXA use in patients with haematuria from the upper urinary tract 4.
Safety of TXA in Patients with Macroscopic Hematuria
- Despite the potential risks, some studies suggest that TXA can be used safely in patients with macroscopic hematuria, including those with autosomal dominant polycystic kidney disease (ADPKD) 5, 6.
- A prospective study published in 2012 found that TXA was effective in stopping bleeding in ADPKD patients with gross haematuria, with no side effects or thromboembolic events reported 5.
- A retrospective study published in 2017 compared the effect of TXA vs etamsylate on hematuria duration in ADPKD patients with persistent gross hematuria, and found that TXA was more effective in stopping bleeding 6.