Beyond Eyelash Lengthening:Prostaglandin Analogues for Scalp and Eyebrows
Scalp alopecias continue to be a challenge to clinicians and cause a major impact on a person's quality of life. Treatment options are limited and often unsatisfactory. The serendipitous
observation that glaucoma treatments improve eyelash growth has been substantiated with the approval of bimatoprost
solution to treat eyelash hypotrichosis. The question then is raised, can these topical medications increase hair growth in other situations, such as alopecia areata of the eyelashes, and other locations, like brows or scalp? Clinical data to date and upcoming clinical trials are reviewed.
Since the initial observation in 1997 that use of ophthalmic latanoprost 0.005% solution for glaucoma also increased the number and length of eyelashes,1 interest has been raised in a new potential intervention for alopecias. Because so few medications
have impact in alopecias, new therapeutic options have generated much interest. Alopecia areata affects up to 3% of the population at some point and androgenetic alopecia affects up to 50% of men and at least 10% of women. Scarring alopecias,
while rare, can have even more significant effects on a person's quality of life.
Prostaglandins are a diverse group of lipid-based signaling molecules derived from fatty acids. They work via autocrine or paracrine signals, in a more local way than systemic endocrine signaling. The prostaglandin F2α analogues latanoprost and bimatoprost are used in treating ocular hypertension and glaucoma.
A noted side effect was increased eyelash hair growth and skin hyperpigmentation, a feature that has been confirmed in several small scale studies. Eventually, clinical trials led to the approval of bimatoprost as Latisse for treatment of eyelash hypotrichosis. Several types of prostaglandin analogues are FDA-approved for use in medicine:
Prostaglandin F2 alpha analogues: decrease intraocular pressure
and treats open-angle glaucomaLatanoprostBimatoprostTravoprostCarboprost
Related medications used for other indications in medicine
Synthetic prostaglandin E1: decreases gastric acid production, induces uterine contractions, treats erectile dysfunction
Of the prostaglandin F2alpha inhibitors, bimatoprost (marketed
as Lastisse® and Lumigan®) has been approved to increase eyelash length, thickness, and number. The related molecule latanoprost (Xalatan®) has shown the most promise and has the most clinical data on increasing hair growth to the eyebrows, and the scalp. Because it has been initially approved for intraocular
use, both topical and intralesional injections have been tried. Compared to oral medications, these have the advantage of minimizing systemic effects, important for safety and for potential
use in older patients taking multiple medications.