International research involving Mayo Clinic researchers may lead to new relief for migraine sufferers.
The disabling headaches experienced by 30 million Americans, most of them women, are commonly treated with drugs when nonprescription analgesics don't help.
But migraine patients often must weigh the benefits of drug treatment against uncomfortable side effects such as dizziness, chest and throat tightness, tingling sensations and flushing.
Patients with a history of cardiovascular disease can't use the effective migraine drugs, triptans, because they constrict blood vessels.
Researchers at Mayo Clinic and other medical centers have been looking into a new migraine-specific drug called telcagepant as a promising alternative that would produce fewer side effects than the established treatments.
Telcagepant works by blocking the actions of brain proteins thought to play a role in causing migraines. This drug does not constrict blood vessels and appears to not cause vascular problems.
Mayo Clinic researchers in 2007 helped lead a large international study assessing the effectiveness and side effects of telcagepant.
Now a study published in the British medical journal Lancet reports that telcagepant is as effective, but results in fewer side effects than a leading triptan medication.
"These results make it clear that this new medication could become a useful alternative for treating acute migraine headaches. It works as well as existing treatments, but with less discomfort from side effects," says David W. Dodick, M.D., a neurologist at Mayo Clinic in Arizona and one of the study's authors.
Conducted at 81 sites, the study involved 1,380 adult patients, 85 percent of them women, who suffered from migraines. Study participants experiencing acute migraine episodes were treated with either telcagepant, a placebo (a "fake" pill with no medicinal value) or a widely used triptan medication called zolmitriptan.
At two hours and again at 24 hours after treatment, the patients were evaluated for pain intensity and side effects, including nausea and sensitivity to sound or light. The medications were equally effective in reducing or eliminating pain, but differences appeared in assessing side effects.
Zolmitriptan's rate of adverse side effects averaged 51 percent, while that for telcagepant was only 34 percent, a near-match of the placebo's 32 percent. The most common adverse side effects for zolmitriptan were dizziness, dry mouth, fatigue, difficulty sleeping, nausea, tingling or numbness, chest discomfort, throat tightness, myalgia and feeling hot.
Telcagepant had a much shorter list of common side effects: dry mouth, difficulty sleeping, nausea and fatigue. Patients using the new drug reported more vomiting, but they also reported vomiting more frequently as a symptom of migraine before treatment. Telcagepant produced less nausea and sound and light sensitivity, even at the highest dose, than zolmitriptan did.
Dr. Dodick, who is president-elect of the American Headache Society, said the findings are significant news for migraine sufferers. This drug expands the therapeutic options for sufferers, especially those who cannot use, or do not respond, to current treatments, and represents a new treatment with a novel mechanism of action "the first since the triptan era began 18 years ago.
While further studies are being conducted, FDA approval for telcagepant is expected to be sought later this year.
Reference: Mayo Clinic is the first and largest integrated, not-for-profit group practice in the world. As a leading academic medical center in the Southwest, Mayo Clinic focuses on providing specialty and surgical care in more than 65 disciplines at its outpatient facility in north Scottsdale and at Mayo Clinic Hospital. The 244-licensed bed hospital is located at 56th Street and Mayo Boulevard (north of Bell Road) in northeast Phoenix, and provides inpatient care to support the medical and surgical specialties of the clinic, which is located at 134th Street and Shea Boulevard in Scottsdale.