Allergan to seek approval for botulinum toxin (Botox) to cure chronic migarine headache

Botox therapy reduced the number of headache episodes and the number of headache days, studies found

Botox, which uses botulinum toxin as active drug, could become a therapy to cure chronic migraine.

Botox is currently being promoted as an injection to smooth out wrinkles by its maker Allergen Inc.

Botox, purified from the poison botulinum extracted from the bacteria that causes fatal food poisoning in humans, is administered by doctors as an injection in facial skin. Botulinum toxin which causes paralysis of the muscles in the body, clears wrinkles on the skin by paralysing the muscles underneath.

Allergan has done some phase III clinical studies using Botox in magraine patients across the US and European continents and published the data in peer reviewed medical journals.

Preliminary data from the studies were released on Sept. 11, 2008. Botox injections were shown better than placebo shots at decreasing the number of days patients had headaches, though the frequency of headaches was similar.

Study data also showed that Botox therapy reduced the number of headache episodes and the number of headache days.

Allergan now plans to submit the data showing Botox’ efficacy in chronic migraine patients to the US FDA seeking approval for the new indication.

Allergan expects to supply the data to US FDA before Sept. 30, reports say quoting Allergen officials.

Allergan has been promoting Botox off-label for chronic migraine headache for sometime now.A bout $50 million of $1.3 billion in revenue generated last year by Botox came from its unapproved use as a migraine treatment, say analysts.

Currently, no drug has been approved for chronic migraine headache.

Painkillers and the generic drug ergotamine are used for sympto relief. London-based GlaxoSmithKline Plc.$1.3 billion (2008) Imitrex is also used to prevent migraine attack.

Other unapproved  drugs used to treat migraine attacks include beta blockers and Topamax, made by New Brunswick, New Jersey-based Johnson & Johnson.

Allergan began studies using Botox for migraines after doctors linked the drug to migraine relief in case studies.

A dermatologist at the University of California San Francisco, Richard Glogau reported at the American Society of Dermatologic Surgery meeting in November patients given Botox to remove frown lines also reported having fewer migraines.

But researchers are not sure how Botox cure migraine headaches.

Some researchers believe that Botox may stop pain messages from reaching the brain.

However, higher doses – about 200 units – of botulinum toxin will be required to treat migraine headaches, unlike in cosmetic procedure to smoothen out wrinkles where only 25 units of Botox is sufficient.A vial of Botox containing 100 units costs $609.98 on drugstore.com.

Allergan is also studying Botox for use in strokes. In May, the FDA rejected Allergan’s application seeking approval for Botox use in patients who have suffered a stroke.

In April, US FDA slapped the strictest US warning about the risks of botulinum. The warning applies to all botulinum toxins used to smooth forehead lines or treat neurological disorders. Story

Chronic migraine headache
Chronic migraine headaches must occur at least 15 days a month, for more than three months. Chronic migraine usually evolves from episodic migraine without aura affecting mostly only one side of your head, pulsating or throbbing pain, moderate to severe intensity, aggravated by physical activity. It may be associated with nausea or vomiting, sensitivity to light and sound. Normally migraine headaches starts suddenly and occurs daily within three days of onset

The causes of chronic daily headaches are not well understood. Some may be caused by various underlying diseases or conditions, including: inflammation or other problems with the blood vessels in and around the brain, infections, such as meningitis, intracranial pressure that’s either too high or too low, pinched nerves in the neck, brain tumor and traumatic brain injury.

In most cases, however, chronic daily headaches don’t have an underlying physical cause.

An estimated 3 percent to 5 percent of adults worldwide experience chronic daily headaches.