240 patients undergoing total knee arthroplasty (TKA) were randomized to examine the efficacy of temporary clamping of the drain with or without tranexamic acid for haemostasis. Patients were divided into four groups; a control group fitted with a drain (no clamping) and a placebo injection, a group undergoing drain clamping and a placebo injection, a group fitted with a drain (no clamping) and an injection of tranexamic acid, or a group receiving both clamping of the drain and tranexamic acid. Results after the first 48 hours demonstrated that patients who received both treatments had the lowest mean postoperative volumes of drained blood and amount of blood transfusions required.