Botox OK'd in Canada to fight chronic migraines

Health Canada has approved the anti-wrinkle treatment Botoxfor people who suffer with chronic migraines at least 15 days a month.

Botox, or onabotulinumtoxinA,can now be used asa preventive treatment for adults who have headaches that last fours hours a day or more for half a month, maker Allergan, Inc. announced Monday.

Health Canada'sapproval was based on clinical trial data involving 1,384 adults collected by the drug's maker.

In the clinical trial, those treated with Botox experienced fewer headache days and less time with headaches compared with those taking placebo, the company said.

Adverse reactions reported by morethan two per cent of patients treated with the drug and more frequently than in patients treated with placebo included:

• Eyelid drooping.
• Pain at the injection site.
• Sinusitis.
• Bronchitis.
• Neck pain.
• Musculoskeletal stiffness or pain.
• Muscular weakness.
• Myalgia (muscle pain).
• Headache.
• Migraine.
• Loss of facial muscle motor function or facial paresis.

Botox is made from a neurotoxic protein that in large doses can cause the paralytic illness botulism.

Itis also authorized in Canada for non-cosmetic purposes to treat spasticity in muscles andmuscle stiffness, and to decrease muscular responsiveness. It is best known for its cosmetic uses, such as its ability to counter the appearance of moderate to severe frown lines between the eyebrows and around the eyes.

In 2009, Health Canada announced new labelling information for the drug to indicate the toxin in Botox productsmay spreadto distant parts of the body.