Tranexamic Acid

Abstract

Tranexamic acid, a synthetic derivative of the amino acid lysine, is an antifibrinolytic agent that acts by binding to plasminogen and blocking the interaction of plasmin(ogen) with fibrin, thereby preventing dissolution of the fibrin clot. Tranexamic acid (Transamin®) is indicated in Japan for use in certain conditions with abnormal bleeding or bleeding tendencies in which local or systemic hyperfibrinolysis is considered to be involved. This article reviews the efficacy and tolerability of tranexamic acid in conditions amenable to antifibrinolytic therapy and briefly overviews the pharmacological properties of the drug. In large, randomized controlled trials, tranexamic acid generally significantly reduced perioperative blood loss compared with placebo in a variety of surgical procedures, including cardiac surgery with or without cardiopulmonary bypass, total hip and knee replacement and prostatectomy. In many instances, tranexamic acid also reduced transfusion requirements associated with surgery. It also reduced blood loss in gynaecological bleeding disorders, such as heavy menstrual bleeding, postpartum haemorrhage and bleeding irregularities caused by contraceptive implants. Tranexamic acid significantly reduced all-cause mortality and death due to bleeding in trauma patients with significant bleeding, particularly when administered early after injury. It was also effective in traumatic hyphaema, gastrointestinal bleeding and hereditary angioneurotic oedema. While it reduces rebleeding in subarachnoid haemorrhage, it may increase ischaemic complications. Pharmacoeconomic analyses predicted that tranexamic acid use in surgery and trauma would be very cost effective and potentially life saving. In direct comparisons with other marketed agents, tranexamic acid was at least as effective as ε-aminocaproic acid and more effective than desmopressin in surgical procedures. It was more effective than desmopressin, etamsylate, flurbiprofen, mefenamic acid and norethisterone, but less effective than the levonorgestrel-releasing intra-uterine device in heavy menstrual bleeding and was as effective as prednisolone in traumatic hyphaema. Tranexamic acid was generally well tolerated. Most adverse events in clinical trials were of mild or moderate severity; severe or serious events were rare. Therefore, while high-quality published evidence is limited for some approved indications, tranexamic acid is an effective and well tolerated antifibrinolytic agent.

Tranexamic acid: a clinical review

“…The binding of TXA to plasminogen is 6 to 10 times more potent that of e-ACA [7]. TXA has been shown to increase thrombus formation in a dose-dependent fashion in animal models, in contrast to aprotinin, which inhibits thrombus formation [8].…”

“…Topical administration results in a ten-fold less plasma concentration of TXA when compared to intravenous administration [8,64], with a potential reduction in adverse effects. Although topical TXA has been studied in cardiothoracic [65−68], orthopedic [64, 69−72], otorhinolaryngologic [73,74] and orthognathic [75−77] surgeries, high-quality trials are lacking.…”

“…The biological mechanism involves the inhibition of the complement system by TXA in the presence C1 esterase deficiency and partial normalization of plasma kinin activation [130]. In Japan, TXA is approved for conditions such as urticarial swelling, itch, eczema, drug eruptions or toxicoderma [8], in which local hyperfibrinolysis and inflammation are involved [131].…”

“…Recently a dose-response relationship of TXA has been proposed as a modifiable risk factor for seizures for patients undergoing cardiac surgery [139]. TXA crosses the blood-brain barrier and penetrates the eye, and produces cerebrospinal fluid concentration levels around 10% of the plasma concentration [8]. Likewise, it diffuses into and out of synovial membranes and joint fluid.…”

“…Gastrointestinal disturbance, allergic skin reaction, visual disturbance occur more commonly [8] and seizures less commonly at high concentrations.…”