SANTA ANA, Calif. – The Food and Drug Administration has approved Botox as a treatment for chronic migraines.
Irvine, Calif.-based Allergan, which makes Botox, announced Friday that it had received a letter from the FDA granting the approval for the use of Botox as a method of preventing migraines in patients who have the headaches an average of 15 or more days per month and lasting four hours a day or more.
An estimated 3.2 million Americans are affected by chronic migraines, the company said.
In a typical treatment session, a headache specialist such as a neurologist injects a total of 155 units of Botox into seven sites in the head and neck, an Allergan spokeswoman said.
In many cosmetic Botox sessions, doctors inject a total of 100 units of the diluted form of botulinum toxin into the forehead and around the eyes.
The safety and effectiveness of Botox has not been established for the treatment of episodic migraine, Allergan said.
In July, British regulators approved Botox for migraine sufferers.
Allergan has been running clinical trials of Botox as a treatment for migraines since 2004.
In the United States, because Botox is approved for other uses, doctors such as Dr. Susan Hutchinson at the Orange County Migraine and Headache Center in Irvine have already prescribed it routinely as a treatment for migraine sufferers. Observers predict that FDA approval will expand the number of doctors willing to offer Botox as a migraine treatment.