Tranexamic acid a promising treatment for melasma
Tranexamic acid (TA) shows potential in the treatment of melasma, demonstrating efficacy when used alone or in combination with other modalities while inducing relatively few side effects, according to a literature review.
The review included 15 studies evaluating the effects of TA on melasma as administered by oral, topical or physical (injection and micro-needling) route. Assessments included the Melasma Area and Severity Index (MASI), modified Melasma Area and Severity Index (mMASI), melanin (MI) and erythema index (EI), and physician global assessment (PGA).
In the nine studies exploring the oral route of administration, TA was associated with significant reductions in MASI, mMASI, MI and EI scores over a treatment course of 2 to 8 months. The drug induced significant clinical improvements in melasma whether used alone or in combination with laser therapy, or with a triple combination of topical fluocinolone acetonide, tretinoin and hydroquinone. [Am J Clin Dermatol 2017;doi:10.1007/s40257-017-0263-3]
The four studies evaluating topical TA showed that 12 weeks of treatment led to significant improvements in MASI and mMASI scores, which did not significantly differ from those achieved with either a vehicle placebo gel or topical hydroquinone/dexamethasone. Results indicated that topical TA and hydroquinone/dexamethasone were equally effective for melasma, whereas the MASI score reductions with TA vs placebo were attributed to the application of adequate sunscreen.
Meanwhile, one study reported the efficacy of weekly intradermal injections of TA over 12 weeks, inducing a significant decrease in MASI score by the fourth week of treatment and an even greater reduction after 8 and 12 weeks. Another study showed the superiority of micro-needling to micro-injection of TA, with more patients in the micro-needling group achieving 50-percent clinical improvement.
Side effects were rare, and there were no major adverse events (AEs). The most commonly reported AEs, regardless of route of administration, included mild gastrointestinal discomfort, erythema, burning, hypomenorrhea, palpitations, allergic skin rashes, alopecia, drowsiness, scaling and xerosis.
Noting that most of the included studies recommended the use of sunscreen to patients, researchers pointed out that four studies evaluating the effect of oral TA in combination with another treatment modality on melasma demonstrated that sunscreen use was not a confounding factor and TA can be credited for the treatment response. “Overall, oral TA and physical methods of delivery appear to demonstrate the most evidence of efficacy despite sunscreen use.”
Melasma is a common skin disorder characterized by hyperpigmented macules or patches frequently found on the cheeks, forehead and upper lip. Having a propensity for recurrence, the condition may negatively impact on psychosocial functioning in affected individuals. Current treatments including hydroquinone, kojic acid and retinoids, among others, have been shown to have variable efficacy and side-effect profiles. [Australas J Dermatol 2015;56:151–63; Acupunct Med 2015;33:254–61]
The present data support a role of TA (a synthetic derivative of the amino acid lysine) in the management of melasma, although additional studies are warranted to establish the optimum dose and route of administration and an accurate side-effect profile.
Researchers noted that the treatment’s main mechanism of action involved the prevention of the conversion of plasminogen to plasmin, which is a known melanogenic factor.
“The therapeutic effects of TA in dermatology are extensive and should therefore be considered for a myriad of indications in addition to melasma. Its demonstrated effectiveness against hyperpigmentation through inhibition of plasmin activity makes it a possible treatment option for other pigmentary conditions such as post-inflammatory hyperpigmentation and that resulting from UV radiation,” they added.