==== Front EXCLI J EXCLI J EXCLI J EXCLI Journal 1611-2156 Leibniz Research Centre for Working Environment and Human Factors 2020-3161 10.17179/excli2020-3161 Doc1547 Letter to the Editor Efficacy of tranexamic acid in patients with traumatic brain injury Kawada Tomoyuki *1 1 Department of Hygiene and Public Health, Nippon Medical School *To whom correspondence should be addressed: Tomoyuki Kawada, Department of Hygiene and Public Health, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-Ku, Tokyo 113-8602, Japan; Phone: +81-3-3822-2131, E-mail: kawada@nms.ac.jp 08 12 2020 2020 19 1547 1548 13 11 2020 07 12 2020 Copyright © 2020 Kawada2020This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (http://creativecommons.org/licenses/by/4.0/) You are free to copy, distribute and transmit the work, provided the original author and source are credited.This article is available from https://www.excli.de/vol19/excli2020-3161.pdf ==== Body  Dear Editor, Several results have been reported on the efficacy of tranexamic acid (TXA) in patients with acute traumatic brain injury (TBI). As such, Lawati et al. (2020[4]) conducted a meta-analysis to determine the safety and efficacy of TXA in these patients. The authors summarized nine randomized controlled trials (RCT), which resulted in a pooled relative risk (RR) (95% confidence interval [CI]) of TXA of 0.95 (0.88-1.02) for mortality. There was also no significant difference in disability assessed using the Disability Rating Scale. Furthermore, the pooled RR (95% CI) of TXA for hematoma expansion was 0.77 (0.58-1.03). Although the use of TXA did not increase the risk of adverse events, no advantages were observed for using TXA in TBI patients. Rowell et al. (2020[5]) conducted a double-blinded RCT to determine whether TXA treatment initiated in the out-of-hospital setting within 2 hours of injury improved neurologic outcome in patients with moderate or severe TBI. Similarly, TXA administration did not improve the 6-month neurologic outcome as measured using the Glasgow Outcome Scale-Extended. Cone et al. (2020[1]) also commented that a large trial assessing efficacy with optimized dosing protocols, a mortality end point, and specific focus on the TBI severity cohorts should be conducted to verify the existence of benefits. In contrast, an RCT report presented that the adjusted RRs (95% CIs) of TXA for mild-to-moderate and severe TBI death were 0.78 (0.64-0.95) and 0.99 (0.91-1.07), respectively (CRASH-3 trial collaborators, 2019[2]). In addition, early treatment was more effective than later treatment in patients with mild-to-moderate head injury that could result in death. This means that the level of severity in patients with TBI is important for subsequent clinical interventions. There is a comment regarding the inconsistent results (Kawada, 2020[3]), and a meta-analysis of RCTs ensuring high-quality of each trial should be conducted with special reference to the level of severity. Conflict of interest The author declares no conflict of interest. ==== Refs 1 Cone DC Spaite DW Coats TJ Out-of-hospital tranexamic acid for traumatic brain injury JAMA 2020 324 946 947 32897330 2 CRASH-3 trial collaborators Effects of tranexamic acid on death, disability, vascular occlusive events and other morbidities in patients with acute traumatic brain injury (CRASH-3): a randomised, placebo-controlled trial Lancet 2019 394 1713 1723 31623894 3 Kawada T The efficacy of tranexamic acid for brain injury Am J Emerg Med 2020 article in press 10.1016/j.ajem.2020.07.048. Available from: 10.1016/j.ajem.2020.07.048 4 Lawati KA Sharif S Maqbali SA Rimawi HA Petrosoniak A Belley-Cote EP Efficacy and safety of tranexamic acid in acute traumatic brain injury: A systematic review and meta-analysis of randomized-controlled trials Intensive Care Med 2020 epub ahead of print 10.1007/s00134-020-06279-w. Available from: 10.1007/s00134-020-06279-w 5 Rowell SE Meier EN McKnight B Kannas D May S Sheehan K Effect of out-of-hospital tranexamic acid vs placebo on 6-month functional neurologic outcomes in patients with moderate or severe traumatic brain injury JAMA 2020 324 961 974 32897344