Oral and Intravenous Tranexamic Acid Are Equivalent at Reducing Blood Loss Following Total Hip Arthroplasty

BACKGROUND Tranexamic acid is an antifibrinolytic that has been shown to reduce blood loss and the need for transfusions when administered intravenously in total hip arthroplasty. Oral formulations of the drug are available at a fraction of the cost of the intravenous preparation. The purpose of this randomized controlled trial was to determine if oral and intravenous formulations of tranexamic acid have equivalent blood-sparing properties. METHODS In this double-blinded trial, 89 patients undergoing primary total hip arthroplasty were randomized to receive 1.95 g of tranexamic acid orally 2 hours preoperatively or a 1-g tranexamic acid intravenous bolus in the operating room prior to incision; 6 patients were eventually excluded for protocol deviations, leaving 83 patients available for study. The primary outcome was the reduction of hemoglobin concentration. Power analysis determined that 28 patients were required in each group with a ±1.0 g/dL hemoglobin equivalence margin between groups with an alpha of 5% and a power of 80%. Equivalence analysis was performed with a two one-sided test (TOST) in which a p value of