There are many medical uses of Botox® (OnabotulinumtoxinA), including anti-wrinkle treatments.

One of the more recently approved uses of the drug has been for chronic migraine headaches, as the drug was licensed specifically for the treatment of chronic migraine in July 2010 by the Medicines and Healthcare products Regulatory Agency (MHRA).

Botox® has not been shown to be effective for any other headache type (e.g. episodic migraine, tension-type headache, cluster headache) as yet.

Botulinum toxin and headache

A number of clinical trials in various types of headache and the use of botulinum toxin for have been conducted, with no great difference over placebo being found in tension-type headache, episodic migraine, and undifferentiated chronic headache.

However, further analysis of the results suggested that a subgroup of patients, those with chronic migraine who could benefit, and further trials were undertaken.

Botox® in chronic migraine: the PREEMPT trials

Two Phase 3 Research Evaluating Migraine Prophylaxis Therapy (PREEMPT) trials recruited 1384 patients with chronic migraine, and these people were then randomised them to treatment with Botox® or placebo.

These patients were suffering on average 20 days of headache each month, of which 18 were moderate or severe. After 12 months, 70% of those treated with Botox® had half the number of headaches they’d had previously.

How does botulinum toxin work in chronic migraine?

We’re not really sure. Unlike many of the other conditions in which it is used, it is not thought to work by relaxing overactive muscles.

Botulinum toxin has been shown to reduce pain in a number of disease states, including cervical dystonia, neuropathic pain, lower back pain, spasticity, myofascial pain, and bladder pain.

For chronic migraine, it is though that Botulinum toxin may inhibit the release of peripheral nociceptive neurotransmitters, which may then have a knock-on effect on the central pain processing systems that generate migraine headaches.

Is Botox® right for me?

Only patients with chronic migraine are eligible for treatment with Botox®.

Chronic migraine is defined as headaches occurring on 15 or more days each month, at least half of which have migrainous features.

To find out more, call Cosmetic Doctor on 01 685 3100.