Therapeutic efficacy and safety of oral tranexamic acid 250 mg once a day versus 500 mg twice a day: a comparative study.

Oral tranexamic acid (TXA) 250 mg twice daily has been used effectively for 4 weeks to 6 months to treat melasma. As relapses are frequent on discontinuation, a minimum effective dose of TXA that can be used safely for long time remains unknown. We compared the efficacy of oral TXA 250 mg once daily and 500 mg twice daily given for 16 weeks in 132 (m:f 23:109) adults with melasma. 42 patients in Group-A (TXA 250 mg/d) and 46 patients in Group-B (TXA 500 mg twice/d) completed the study. They were followed up at 4-week interval for percentage reduction in baseline Melasma Area Severity Index (MASI) and at 24 and 28 weeks for relapse. Therapeutic response, for both as per-protocol and intention-to-treat analysis, was scored as very good (> 75% reduction), good (51-75% reduction), moderate (25-50% reduction), mild (< 25% reduction) or no improvement. Reduction in mean MASI score at 4 weeks was not statistically significant in Group-A but it decreased significantly 8 weeks onwards and was comparable with that in Group-B. The relapse rate was higher in Group-B (10.8%) than Group-A (4.7%) at the end of 28 weeks. Oligomenorrhoea and abdominal discomfort in few patients did not necessitate treatment discontinuation. TXA 500 mg twice daily showed early reduction in mean MASI score compared to 250 mg given once daily with comparable safety and therapeutic efficacy at 16 weeks. Open-label cross-sectional design, no control arm, small number of patients in each group, MASI score being subjective assessment tool, short duration of treatment and follow-up are study limitations.