ObjectiveTo evaluate the efficacy and safety of a loading high-dose tranexamic acid (TXA) followed by postoperative 5 doses in total hip arthroplasty (THA) by a randomized controlled trial.MethodsSeventy-two patients who underwent primary unilateral THA between December 2017 and March 2018 were randomly divided into two groups (36 patients in each group). A single dose of 20 mg/kg TXA was administered intravenously before 5-10 minutes of operation in group A; and a single dose of 40 mg/kg TXA was administered intravenously in group B at the same time point. All patients received 5 doses of 1 g TXA at 3, 6, 12, 18, and 24 hours after the first dose. There was no significant difference in gender, age, weight, height, body mass index, disease type, and combined medical diseases between the two groups (P>0.05). Total blood loss (TBL), lowest postoperative hemoglobin (Hb) level, fibrinolysis parameters [fibrin (ogen) degradation products (FDP), D-dimer], inflammatory factors [C-reaction protein (CRP), interleukin-6 (IL-6)], adverse events (thrombosis, pulmonary embolism) were recorded and compared between groups.ResultsThe TBL was significantly lower in group B than in group A (P<0.05). Furthermore, the lowest postoperative Hb level was significantly higher in group B than in group A (P<0.05). There was no significant difference in FDP and D-dimer before operation between the two groups (P>0.05). The levels of FDP and D-dimer were significantly lower in group B than in group A at 12 and 36 hours postoperatively (P<0.05). There was no significant difference in CRP and IL-6 before operation between the two groups (P>0.05). The levels of CRP and IL-6 were significant lower in group B than in group A at 12, 24, and 36 hours postoperatively (P<0.05). There was no significant difference at 14 days (P>0.05). There were 2 patients with intramuscular venous thrombosis in group A and 1 in group B after operation, and there was no significant difference in the incidence of embolic events (P>0.05). No deep venous thrombosis or pulmonary embolism occurred in all groups.ConclusionA loading high-dose TXA followed by postoperative 5 doses can further reduce the blood loss, provide additional fibrinolysis and inflammation control in THA, without increasing the risk of embolic events.