P70 A randomized open-label study to compare two different dosage regimens of oral tranexamic acid in treatment of moderate-to-severe facial melasma

Abstract Oral tranexamic acid (TXA) demonstrates promising results in melasma treatment; however, TXA dosing in melasma management has been a cause for persistent speculation. There is still no consensus to guide dosing, duration of TXA therapy and need for maintenance treatment. Our aim was to evaluate and compare the efficacy of two different TXA dosing regimens, 250 mg twice daily vs. 500 mg twice daily in patients with melasma using the modified Melasma Area and Severity Index (mMASI) score. This was a randomized open-label study involving 50 patients aged > 18 years with moderate-to-severe melasma. Patients were randomized into group A (oral TXA 250 mg twice daily) and group B (oral TXA 500 mg twice daily) for 12 weeks and later followed-up monthly to 24 weeks. The primary outcome measure was the proportion of patients achieving a 75% reduction in mMASI (mMASI-75) at 12 weeks from baseline, and a reduction in mMASI and Melasma Quality of Life (MelasQOL) score at 12 and 24 weeks. The proportion of patients achieving mMASI-75 at 12 weeks was 20% in group A and 25% in B (P = 0.71). Both groups showed a statistically significant reduction in mean (SD) mMASI [4.8 (2.2) in group A and 6.8 (3.4) in group B; P = 0.02] at 12 weeks. mMASI remained stable after 12 weeks and was 4.9 (2.43) and 4.92 (2.85) in groups A and B, respectively, at 24 weeks (P = 0.97). The mean (SD) percentage reduction rates in MelasQOL in groups A and B were 41.8 (15.3) and 29.5 (21.5), respectively (P = 0.03). No adverse effects were observed in either group. Both dosing regimens showed comparative efficacy in terms of mMASI reduction at 12 weeks. The improvements achieved were well maintained even after 12 weeks of discontinuing treatment. Hence, lower doses of TXA (i.e. 250 mg twice daily) are equally as effective and safe as higher doses (i.e. 500 mg twice daily). With regard to maintenance dosing, few patients relapsed; hence, not all patients will require tapering or dosing maintenance.