What is the recommended dosage and treatment guidelines for Oral Tranexamic acid (TXA) medication in an adult woman with melasma, considering her overall health and potential risk factors?

Oral Tranexamic Acid Guidelines for Melasma in Adult Women

Recommended Dosage and Treatment Protocol

Oral tranexamic acid should be prescribed at 250 mg twice daily (total 500 mg/day) for 12-16 weeks as adjunctive therapy to topical treatments and strict sun protection, with consideration for combination with intradermal PRP injections for enhanced efficacy. 1, 2

Optimal Dosing Strategy

The evidence supports a tiered approach to oral tranexamic acid dosing:

• Start with 250 mg twice daily (500 mg total daily dose) as this represents the optimal balance between efficacy, safety, and long-term tolerability 3, 4
• The network meta-analysis identified 750 mg per day (250 mg three times daily) for 12 weeks as the optimal dose, though 250 mg twice daily remains acceptable for patients with adherence concerns 3
• Treatment duration should be minimum 12-16 weeks to achieve meaningful improvement, as MASI score reductions become statistically significant only after 8 weeks with lower doses 4
• Higher doses (1000-1500 mg/day) show dose-dependent efficacy but are not necessary for most patients and may increase side effects 5

Position in Treatment Algorithm

Oral tranexamic acid functions as adjunctive therapy, not first-line monotherapy:

• First-line treatment remains triple combination cream (hydroquinone 4%, tretinoin 0.05%, fluocinolone acetonide 0.01%) plus strict sun protection (SPF 50+ reapplied every 2-3 hours) 1, 2
• Add oral tranexamic acid 250 mg twice daily if inadequate response after 8-12 weeks of topical therapy 1, 6
• For moderate-to-severe melasma, combine oral tranexamic acid with intradermal PRP injections (4 sessions every 2-3 weeks), which achieves 90.48% total efficacy versus 73.68% with tranexamic acid alone 7, 1, 2

Safety Screening and Contraindications

Before prescribing, screen for absolute and relative contraindications:

• Absolute contraindications: Recent thrombosis (within 6 months), active thromboembolic disease 7
• Relative contraindications: Atrial fibrillation, known thrombophilia, history of venous thromboembolism 7
• Monitor for side effects: Oligomenorrhea, decreased menstruation, mild gastrointestinal upset (stomach discomfort) 5, 4
• Reassuring safety data: Studies demonstrate tranexamic acid does not increase thromboembolic risk in appropriately screened patients 8

Measuring Treatment Success

• Use modified MASI (mMASI) scores to objectively track improvement at baseline, 4 weeks, 8 weeks, and end of treatment 1, 2, 5
• Response grading: >90% MASI reduction = excellent; 60-90% = moderate improvement; 20-60% = mild improvement 7, 1
• Expect gradual improvement: Significant MASI reduction typically occurs after 8 weeks, with continued improvement through 12-16 weeks 4
• Patient satisfaction should complement objective measurements, as subjective improvement often correlates with adherence 7, 2

Maintenance and Long-Term Management

Melasma is a chronic relapsing condition requiring ongoing management:

• Continue strict sun protection indefinitely: SPF 50+ broad-spectrum sunscreen reapplied every 2-3 hours, wide-brimmed hats (>3-inch brim), UV-protective clothing, shade-seeking during peak hours (10 AM-4 PM) 1, 2
• Lower relapse rates with combination therapy: PRP plus oral tranexamic acid shows reduced recurrence at 3 and 6 months compared to tranexamic acid alone 7, 1
• Consider maintenance PRP treatments every 6 months after initial treatment course 1, 2, 6
• Lower doses (250 mg once daily) may have lower relapse rates (4.7%) compared to higher doses (10.8% with 500 mg twice daily), though this requires further validation 4

Critical Pitfalls to Avoid

• Do not use oral tranexamic acid as monotherapy—it must be combined with topical treatments and sun protection for optimal results 1, 8
• Do not discontinue treatment prematurely—minimum 12 weeks required for meaningful improvement 3, 4
• Do not forget to reapply sunscreen after swimming, sweating, or every 2-3 hours during continuous outdoor exposure 1, 2
• Do not overlook hormonal triggers—counsel patients about oral contraceptives, pregnancy, and hormone replacement therapy that may limit treatment success 1
• Do not ignore lifestyle factors—advise smoking cessation as smoking worsens melasma 1, 2

Enhanced Efficacy Strategy

For patients requiring maximum efficacy:

• Combine oral tranexamic acid 250 mg twice daily with intradermal PRP injections administered monthly for 3-5 sessions, spaced 2-3 weeks apart 7, 1, 2, 6
• This combination maintains normal VEGF and α-MSH levels while reducing disease recurrence 7, 2
• PRP demonstrates superior efficacy compared to intradermal tranexamic acid injections with similar safety profiles 2, 6
• Follow-up evaluation one month after the last PRP treatment 1, 6