Tranexamic Acid for Acute Upper Respiratory Tract Infection‐Associated Sore Throat Pain: A Randomized Controlled Trial

ABSTRACT Background Tranexamic acid (TXA) is sometimes used to relieve sore throat discomfort from acute upper‐respiratory tract infection (URTI), but its clinical effect has not been demonstrated in robust randomized controlled trials. Methods The tranexamic acid for URTI study is a randomized double‐blinded clinical trial that was conducted between November 2023 and March 2025. Patients with URTI and a sore throat (18–65 years old) were randomized to receive either 1 g placebo (lactose) or 1 g preparation of 50% TXA. Randomization was stratified according to age (< 45 vs. ≥ 45 years) and baseline sore throat visual analog scale (VAS) score (< 50 vs. ≥ 50). Change in the proportion of patients with sore throat score more than a moderate level within a 2‐h period after taking TXA was the primary outcome. We also examined the difference in sore throat VAS scale score between before and 2 h after TXA was taken. Data were analyzed using analysis of covariance, controlling for stratification factors. Results We analyzed the 17 participants assigned to each group (total = 34). The groups were not significantly different in the proportion of patients whose sore throat had a moderate or greater impact on their day‐to‐day life (TXA 41.2% vs. placebo 47.1%; p = 1.00). Similarly, they did not significantly differ in mean change of sore throat score on VAS within 30 min (TXA 17.3 vs. placebo 13.1; p = 0.49). No side effects were reported. Conclusion TXA was not significantly better than a placebo at relieving acute URTI‐associated sore throat. Trial Registration UMIN000056394