In this study MAM was defined as a headache occurring regularly in close relationship to the onset of menstruation (between two days prior to and up to four days after the onset of bleeding). Some reports suggest that MAM headaches are more resistant to treatment, and may be more prone to recur compared to migraines that occur at other times during the month. Thirty-three percent of women who get regular migraines begin to experience them at the onset of their first menstrual cycle. It is likely that the reason women experience MAM is related to changes in female sex hormone levels that occur at menstruation.
"There is strong need for preventive intervention, or mini-prophylaxis, for those women who suffer regular, prolonged MAM attacks, and effectively lose several days each month because they are unable to function adequately either at work or at home," said the lead author of the article, Stephen Silberstein, M.D., FACP, professor of Neurology, Jefferson Medical College of Thomas Jefferson University, and director, Jefferson Headache Center, Thomas Jefferson University Hospital. "Frovatriptan has a 26 hour half life, which is associated with a long duration of action and a low risk of headache recurrence. These characteristics suggest that it could be particularly useful in treating MAM attacks, which tend to be prolonged and are prone to recur."
The double-blind, placebo-controlled study included more than 500 female patients who experience MAMs drawn from 36 centers in the United States. At the start of the study, patients identified the dates on which their MAM would most likely occur over the following three months. Participants were randomized to receive either placebo, Frova 2.5 mg once-daily or Frova 2.5 mg twice daily for six days. The patients were instructed to start taking their study medication two days before the anticipated MAM onset date for each of the treated menstrual periods.
"Both doses of frovatriptan were significantly superior to placebo in reducing the incidence of MAM headache, and 50 percent of women were free of MAM during dosing with the twice daily regimen," said Dr. Silberstein. "Frova also significantly reduced MAM severity, duration, functional impairment and the use of rescue medication."
Reduction of headache severity and duration was also noted in patients taking Frova who experienced headaches. Thirty-six percent of placebo-treated patients with MAM headache reported it as being severe, compared with 29 percent of patients taking Frova once-daily and 23 percent of patients treated with Frova 2.5 mg. twice-daily. Total duration of MAM headaches were also reduced with a mean duration of 31.1 hours for placebo treatment compared with 20.3 and 16.6 hours respectively for the q.d. (once daily) and b.i.d. (twice daily) Frova doses.
Both Frova dose regimens also significantly reduced the occurrence of MAM-associated symptoms, such as nausea, vomiting, photophobia and phonophobia, and the use of rescue medication was also significantly reduced. Patients taking both doses of Frova also experienced less functional impairment when compared to those taking placebo.
Both dose regimens were well tolerated, and few patients withdrew from the study due to adverse events. The most commonly reported side effects were headache, nausea and dizziness, and the incidence and type of adverse events were generally similar to those experienced by placebo-treated patients.