An experimental combination of migraine medications may offer faster, longer-lasting relief of symptoms than using either drug on its own, a new study suggests.

Migraines are severe throbbing headaches that can cause vomiting, nausea and a sensitivity to light, sound and smells. No one knows what causes migraines, which affect an estimated 3.5 million Canadians.

In Wednesday's issue of the Journal of the American Medical Association, researchers compared a new combination pill that includes sumatriptan (brand name Imitrex) and naproxen sodium (Anaprox) to either drug alone and to a placebo.

The randomized, double-blind studies involved about 3,000 people in the U.S. who were diagnosed as having migraine and received the drugs for moderate or severe migraine attacks.

Up to 65 per cent of those who received the combination pill said they felt relief after two hours compared with up to 55 per cent who took Imitrex alone, 44 per cent in the naproxen only group, and 28 per cent who took dummy pills.

After 24 hours, up to 48 per cent of people taking the combination pill said the relief lasted, compared with up to 35 per cent for Imitrex alone, 30 per cent for naproxen and 18 per cent for the placebo.

More than 1 target

The combination may work better because it targets migraines on multiple fronts, Dr. Jan Lewis Brandes of the Nashville Neuroscience Group and her colleagues said.

Imitrex is in a class of drugs known as triptans that are used to stop but not prevent migraines, and are meant to be taken as soon as possible after a migraine attack begins. The drug is designed to relieve symptoms by preventing blood vessels from dilating in the brain, which causes the migraine attack.

Naproxen is an older, non-steroidal anti-inflammatory drug or NSAID that reduces inflammation.

Long-term use of NSAIDs increase the risk of stomach bleeding. The researchers said gastrointestinal side-effects were relatively rare, but more common in the combination group than when Imitrex only or a placebo were taken.

Other side-effects of the combination drug included dizziness, drowsiness, numbness, tingling or a "pins and needles" feeling, dyspepsia, dry mouth and chest discomfort.

Like Imitrex, the combination drug would be taken when needed.

The study was sponsored by Pozen Inc., which makes the experimental combination drug, and was also funded by GlaxoSmithKline, which makes Imitrex.

The U.S. Food and Drug Administration is reviewing approval of Pozen's combination tablet, the company said.