- Migraine headaches affect 28 million Americans, 75 percent of whom are women. (NIH, NINDS 2002)
- One in four households in the United States have someone affected by migraine headaches.
- Over two million seniors have migraines or severe headaches. (CDC 2002)
The most common type of vascular headache is the migraine. The cause of migraine headaches is not precisely known. It is clear that genetic factors play a role in determining who develops migraine headaches, and abnormal genes have been identified for some forms of migraine headaches. (NIH, NINDS 2002) Migraine symptoms occur in various combinations and include pain, extreme sensitivity to light and sound, nausea, and vomiting. Some individuals can predict the onset of a migraine with telltale signs that include visual disturbances, called an aura. Triggers for migraines include: lack of food or sleep, exposure to light, anxiety, stress, and hormonal irregularities.
Treatment of migraine headaches
There are two ways to approach the treatment of migraine headaches with drugs: prevent the attacks, or relieve symptoms after the headache occurs. Several drugs for prevention and treatment of migraines have been developed in recent years, including serotonin agonists which mimic the action of this key brain chemical. (NIH, NINDS 2002) Referred to as the triptans, these agents represent an important advance in the treatment of migraine headaches. (Goadsby 2002) Triptans selectively activate the serotonin 5-HT receptor which results in three actions: constriction of cranial blood vessels, inhibition of neurotransmitter release, and reduced transmission in nerve pain pathways. In comparison to other types of drugs for migraine headaches, triptans have distinct advantages including selective pharmacology, fewer side effects, safety and efficacy, and simple consistent pharmacokinetics. (Goadsby 2002) Triptans are not recommended for use in individuals with cardiovascular disease.
Rizatriptan benzoate (Maxalt®), a triptan, is indicated for the acute treatment of migraine headaches. Although Maxalt® has generally been covered in private insurance plans in the U.S. for years, it is still not covered by France’s state-run health-care system. (Fuhrmans 2002) Maxalt® is also not covered in New Zealand, Australia and Portugal; its use is restricted in many Canadian provinces. (see appendix)
Drugs in the pipeline for migraine headaches
- Compounds that target nerves but have no vascular side effects are being tested for the treatment of migraine headaches. (Goadsby 2002)
Many of the current treatments for migraine headaches have vascular effects that produce unwanted side effects and make them contraindicated in certain subsets of patients. Since it is believed that migraine headaches primarily result from neural events that result in dilation of blood vessels, pain and further nerve stimulation, novel approaches are currently directed at nerve activation. Several neuronally active compounds are being tested. In 2001, 10 new medicines were in development for the treatment of migraine headaches. (PhRMA 2002)