|
Early in the 19th century, a German physician, Justinus Kerner, speculated that small amounts of a botulinum toxin (which he called “sausage poison” because it could be found on spoiled meat) might be helpful in treating certain medical conditions characterized by involuntary muscle movements.
Kerner guessed right, although he never knew it. For not until after World War II did scientists begin earnestly investigating the therapeutic uses of botulinum toxins. (Botulus means “sausage” in Latin.) And even then, it took some time to determine how the toxins could be helpful medically.
In 1980, American scientists discovered that one strain of the toxins—which they called type A—could help treat crossed eyes (strabismus). A decade later, after a series of clinical trials, the U.S. Food and Drug Administration (FDA) approved botulinum toxin type A for treating not only strabismus but also eyelid muscle spasms (blepharospasm). In 1989, the pharmaceutical company Allergan began to sell the toxin for these medical purposes under the name Botox.
FDA approval for other therapeutic uses of Botox followed—for cervical dystonia (spasms of the neck and shoulder muscles) in 2000 and for primary axillary hyperhydrosis (excessive underam sweating) in 2004.
In between—in 2002—the FDA also approved Botox for a cosmetic purpose: to smoothe out moderate-to-severe “frown” (glabellar) lines between the eyebrows. A Canadian ophthalmologist had discovered this application of the drug serendipitously. She had observed that some patients given Botox for eye problems also experienced a relaxing of the wrinkles on their foreheads.
In 2009, the FDA approved another botulinum toxin product—marketed in the U.S. under the name Dysport by the pharmaceutical company Medicis—for the treatment of cervical dystonia and forehead wrinkles.
More therapeutic and cosmetic applications of botulinum toxin may follow. Researchers are currently investigating its effectiveness for the treatment of many medical conditions, including headaches and speech impediments caused by vocal cord problems. It is even being studied for improving the appearance of scars and for use in topical products. |