NEW YORK, June 20 (Reuters) -- The treatment of migraine and other debilitating chronic headaches appears to be entering a new era, according to a panel of experts attending the 39th Annual Scientific Meeting of the American Association for the Study of Headache (AASH) meeting in New York.
"Some of the new drugs will offer different routes of administration than are now available, some will be more rapid in onset, some will address the problem of headache recurrence, and some will have fewer side effects," Dr. J. Keith Campbell, AASH president and symposium chair told the gathering.
Pharmaceutical developers presented data supporting the efficacy and safety of the new formulations, which are in varying stages of the federal approval process. The new agents are from a class of drugs called the 5-HT serotonin receptor agonists, or "triptans," and include zolmitriptan (Zeneca Pharmaceuticals), rizatriptan (Merck & Co.), naratriptan (Glaxo Wellcome), and eletriptan (Pfizer).
One of this class of drugs -- sumatriptan (Glaxo Wellcome) -- is already on the market, available by prescription only. A new nasal spray form of the drug is planned. Dr. Stephen O'Quinn, clinical program head for Glaxo Wellcome commented, "The nasal spray has a rapid onset of relief, and is an alternative for people who can't take tablets because of nausea."
According to O'Quinn, naratriptan will be available in pill form, and has a longer duration of action. This new drug many also prevent recurrent headache pain.
Merck recently announced the results of a new study on rizatriptan, which found that the drug provided faster relief of migraine pain than sumatriptan.
"Speed of pain relief is a critical need for migraine sufferers," said Dr. Hester Visser of the Merck Neuroscience Research Center in the U.K. "Rizatriptan worked as fast as 30 minutes for some patients to meet that need."
The triptans are believed to work by constricting abnormally swollen blood vessels in the head, and by blocking pain signals from sensory nerves to the brain.
"This clearly is the biggest advance in the treatment of headache since the introduction of ergotamine in the 1920s," Dr. James Couch of the University of Oklahoma in Oklahoma City told Reuters Health in an interview. The triptans "seem to have a lot in common," said Couch, who is also the AASH president-elect. "They all work 75% to 80% of the time.... And though the numbers will vary from study to study, it still seems as though 20% of patients won't respond." For the clinician, this means "trial and error, balancing efficacy with side effects and speed of onset of action."
Another important factor will be cost, Couch noted. "Patients are looking at that aspect very closely. They ask, 'Is this a $12 or $15 headache (referring to the cost of a dose of sumatriptan), or can I treat it with 60 cents worth of over-the-counter medicine?'" Finally, "as a class, the triptans will all have a risk of coronary vasoconstriction," and there is increasing evidence that "once patients start taking a lot of triptans, there is potential for rebound withdrawal."
It is estimated that there are 23 million people in the U.S. who suffer from migraines. Most of those affected are women (75% to 80%) between the ages of 20 and 59. In addition to headache, symptoms of migraine include: nausea, vomiting, and sensitivity to light and sound. Some patients also experience an "aura" -- visual changes such as flashing lights -- or weakness in one side of the body.
