Last Updated: 2008-12-26 10:12:17 -0400 (Reuters Health)

BOSTON (Reuters) – Allergan Inc, maker of Botox, said on Friday that the U.S. Food and Drug Administration has approved its eyelash-thickening drug Latisse.

Latisse is designed to treat hypotrichosis of the eyelashes. The active ingredient in Latisse is bimatroprost, the same ingredient that is in Allergan’s glaucoma treatment Lumigan. Patients taking Lumigan found a side effect of the drug to be eyelash growth.

Latisse is a once-daily prescription treatment that a patient applies to the base of the upper eyelash with a sterile, single-use-per-eye disposable applicator. Once treatment is stopped, eyelashes will gradually return to where they were prior to treatment.

Allergan said it estimates global peak sales of Latisse solution could top $500 million a year.

Latisse is a structural prostaglandin analog. These receptors are present in hair and are thought to be involved in the development and regrowth of the hair follicle.

Side effects of Latisse can include eye redness, itchy eyes and a darkening of the eyelid skin. Though not reported in clinical studies, Allergan said Latisse may also cause the iris to become browner, something that could be permanent.

Allergan said it expects to launch the product in the first quarter of 2009.