GlaxoSmithKline announced the availability of new Imitrex tablets, a novel formulation of GSK's leading migraine therapy. The new formulation contains the same active ingredient with the same proven efficacy and safety profile of the conventional Imitrex tablets now with an innovative technology for rapid disintegration of the product in the stomach.

The rapid-release technology of new Imitrex tablets works differently from oral disintegrating tablets, also known as oral melts, which dissolve on the tongue. New Imitrex tablets, which replace the old tablets, are swallowed whole with water like conventional tablets. The new formulation has been designed to dissolve within minutes. In an invitro study, the new tablet dissolved five times faster than conventional tablets - which may allow the drug to be absorbed into the blood stream quickly. Further studies are needed to establish the relationship between dissolution and efficacy.

Imitrex was the first migraine medication to deliver proven pain-free results. Previous studies with conventional Imitrex tablets showed that 57 per cent of patients who treated with 100 mg tablets in the mild pain phase - and 50 per cent with 50 mg - were pain free at two hours.

A recent study with the new tablets showed that 66 per cent of patients who treated with 100 mg in the mild pain phase - and 51 per cent with 50 mg - were pain free at two hours. These results are based on a multicentre-randomized, double-blind, placebo-controlled single-attack study in the intent-to-treat population. Patients (n=432) were instructed to treat during the mild pain phase of their migraine, within one hour of the onset of pain, and to avoid the use of other medications. Not all of these patients complied with these instructions. In a prospective analysis of those patients who did follow the instructions (n=313), 75 per cent of patients who took new Imitrex 100 mg tablets (53 per cent, 50 mg tablets) reported being pain free at two hours.

Imitrex also treats the associated symptoms of migraine, including nausea, vomiting, and sensitivity to light and sound and were generally well tolerated. In the clinical trial, the most common adverse events reported with new Imitrex 100 mg and 50 mg tablets, respectively, were: nausea and vomiting, chest symptoms and malaise and fatigue.

"This new formulation is designed to help overcome the problems associated with gastric stasis, the slow movement of the stomach which commonly occurs during migraine attacks. This condition may slow the absorption of oral medications," said Dr Frederick Taylor, headache specialist and neurologist at Park Nicollet Health Services (PNHS) and associate professor of Clinical Neurology at the University of Minnesota School of Medicine. "A recent clinical trial showed that two-thirds of patients who were instructed to take new Imitrex 100 mg tablets during the mild pain phase were pain free at two hours."

Migraine affects 28 million Americans, 70 per cent of whom are women. Imitrex targets the nerves and blood vessels that are believed to trigger the total migraine - pain, nausea, sensitivity to light and sound.