The US Food and Drug Administration (FDA) has approved onabotulinumtoxinA (Botox; Allergan Inc) for headache prophylaxis in patients with adult chronic migraine who suffer headaches on 15 or more days per month, each lasting more than 4 hours.
OnabotulinumtoxinA was first approved by the FDA 21 years ago for the treatment of strabismus and blepharospasm, and it is now approved for a variety of indications including upper limb spasticity, cervical dystonia, as well as severe primary hyperhidrosis, and in lower doses, to temporarily improve the look of moderate to severe frown lines between the eyebrows, called glabellar lines.
