What is the recommended dosing schedule for tranexamic acid (TXA) on heavy menstrual bleeding days?

Tranexamic Acid Dosing for Heavy Menstrual Bleeding

For heavy menstrual bleeding, take tranexamic acid 1,300 mg (two 650-mg tablets) orally three times daily (total 3.9 g/day) for up to 5 days during menstruation, starting on the first day of heavy bleeding. 1, 2, 3

Standard Dosing Regimen

• The FDA-approved dose is 1,300 mg three times daily (every 8 hours) for a maximum of 5 days per menstrual cycle, which has been validated in multiple randomized controlled trials 2, 4, 3
• This 3.9 g/day regimen reduces menstrual blood loss by 40-60%, significantly more than the lower 1.95 g/day dose 1, 2, 3
• Treatment should begin on the first day of menstrual bleeding and continue for up to 5 days, stopping when heavy bleeding resolves 1, 3

Pharmacokinetic Rationale

• Plasma concentrations reach therapeutic levels (≥5 μg/mL) within 1.5 hours of dosing, with the modified-immediate-release formulation maintaining levels in the therapeutic range (5-15 μg/mL) when dosed every 8 hours 4
• The plasma half-life of approximately 120 minutes necessitates three-times-daily dosing to maintain antifibrinolytic effect throughout the day 5, 4
• Food does not significantly affect absorption of the immediate-release formulation, allowing flexible administration 4

Clinical Efficacy Evidence

• The 3.9 g/day dose met all three primary efficacy endpoints in pivotal trials: mean reduction in menstrual blood loss of 69.6 mL (40.4% reduction), exceeding the 50 mL threshold, and achieving reductions considered meaningful by patients 2, 3
• This dosing is significantly more effective than NSAIDs (mefenamic acid, flurbiprofen), etamsylate, and oral luteal phase progestins 1, 6
• Quality of life improvements are significant, with 81-94% of women reporting satisfaction and decreased menstrual blood loss 6, 3

Safety Profile and Contraindications

• Absolute contraindications include active thromboembolic disease, history of thrombosis or thromboembolism, or intrinsic risk for thrombosis 7, 1
• Use with extreme caution in patients on oral contraceptive pills due to increased thrombotic risk 8, 5
• Avoid in patients with massive hematuria due to risk of ureteric obstruction from clot formation 9
• Dose adjustment required in renal impairment as tranexamic acid is renally excreted 5, 9

Common Pitfalls to Avoid

• Do not use the lower 1.95 g/day dose, as it failed to meet all primary efficacy endpoints in dose-response studies 2
• Do not confuse the menstrual bleeding dosing (3.9 g/day for 5 days) with acute hemorrhage dosing (1 g IV loading dose followed by 1 g infusion over 8 hours) 7, 8
• Do not extend treatment beyond 5 days per cycle, as safety and efficacy data are limited beyond this duration 1, 3
• Gastrointestinal adverse events (nausea, vomiting, diarrhea) occur in approximately 12% of patients but are generally mild to moderate 6, 3

Alternative Considerations

• If tranexamic acid is contraindicated or ineffective, NSAIDs (mefenamic acid 500 mg three times daily for 5-7 days) can reduce menstrual blood loss by a lesser degree 7, 6
• The levonorgestrel-releasing intrauterine system reduces menstrual blood loss more than tranexamic acid (96% reduction) but causes amenorrhea in 44% of users, which may be unacceptable to some patients 6