Tranexamic acid (TA) is a synthetic derivative of lysine utilized as an antifibrinolytic agent to prevent bleeding (for dental surgery in patients with hemophilia, post-cardiac bypass surgery patients, or in women with menorrhagia) and as a treatment option for hereditary angioedema. Despite these indications, according to the Cochrane Database, there is inadequate evidence to assess whether or not TA (or the other lysine antifibrinolytic, epsilon aminocaproic acid) decreases bleeding. Existing trials are also too small to ascertain the risk of thromboembolic events or other adverse reactions (1).
The theory behind using TA for melasma is based on the presumption that vascular factors may play a role its pathogenesis, and that inhibition of the plasminogen/plasmin pathway could be beneficial (2). TA also inhibits UV-induced plasmin activity in keratinocytes, resulting endothelin-1 (ET-1) suppression. ET-1, believed to be secreted from keratinocytes, is a well-known melanogenic factor. Based on this hypothesis, Kim et al reported that 22 of 23 patients with mild melasma had improvement after applying 2% TA to the whole face for 12 weeks (3).
The first reference I could find regarding the use of oral TA for melasma was by Cho et al, who administered it in combination with IPL and a low fluence Nd:YAG laser, versus the IPL and laser alone – the group with TA added to the regimen fared better, without any adverse reactions after 8 months (4). In the most recent study of oral TA, 561 patients (91.4% female, 8.6% male) were enrolled. Median duration of treatment was 4 months. The majority (503 [89.7%]) improved, 56 (10.0%) had no improvement, and 2 (0.4%) worsened. Patients without family history of melasma had better response rates than those with family history (90.6% vs. 60.0%, P = .01). Of the 503 who improved, response was seen within 2 months of TA initiation, with a relapse rate of 27.2%. Adverse events occurred in 40 (7.1%), reported as abdominal bloating and headache. Most were transient, but 1 developed deep vein thrombosis requiring prompt discontinuation. She was subsequently diagnosed with familial protein S deficiency. The authors conclude by stating that oral TA may be effective for refractory melasma. They advise screening for personal and familial risk factors for thromboembolism prior to initiation of treatment. If prescribed, they recommend discontinuing oral TA if there is no improvement by 3 months (5).
I know that melasma is very distressing for many patients, and that current treatments are relatively unsatisfactory. I am also bemused by the fact that while hydroquinones are undergoing scrutiny for their potential toxicity, TA, which can theoretically cause thromboembolism and seizures (6), is being touted as beneficial. Perhaps it will be. For the moment, I will not be discussing it as an option for my patients. If I ever prescribe it, I will probably be the last kid on the block to do so.
- Estcourt LJ, et al. Antifibrinolytics (lysine analogues) for the prevention of bleeding in people with haematological disorders. Cochrane Database Syst Rev 2016; Mar 15:3: CD009733.
- Tan AW, et al. Oral tranexamic acid lightens refractory melasma. Australas J Dermatol 2016 May 13 [Epub ahead of print]
- Kim SJ, et al. Efficacy and possible mechanisms of topical tranexamic acid in melisma. Clin Exp Dermatol 2016; 41: 480-5.
- Cho HH. Role of tranexamic acid in melisma patient treated with IPL and low fluence QS Nd: YG laser. J Dermatolog Treat 2013; 24: 292-6.
- Lee HC, et al. Oral tranexamic acid (TA) in the treatment of melasma: A retrospective analysis. J Am Acad Dermatol 2016; 75: 385-92.
- Manji RA, et al. Seizures following cardiac surgery: the impact of tranexamic acid and other risk factors. Can J Anaesth 2012; 59: 6-13.