Migraine preventive medications: a reappraisal.

Newer acute care migraine medications demonstrate improved rapidity of action, consistent effectiveness, excellent safety profiles, and rarely cause rebound headaches. Their use could decrease the need for migraine-preventive medication. The present analysis derives a formula that can be used by practitioners to determine the cost-effectiveness of various migraine-preventive medications relative to selected acute-care medications. We propose a measure called the cost-equivalent number (CEN), the number of headaches per month at which the cost of the preventive medication equals the cost savings in acute-care treatment realized by using the preventive medication. The use of the CEN individualizes the decision of whether to use a migraine-preventive medication, weighing both the efficacy and cost of the preventive medication against the cost of the acute-care medication. A CEN lower than the migraine frequency suggests that use of a preventive medication will be cost-effective.