This article originally appeared in BMJ USA

In the last 10 years, the management of migraine headache has changed dramatically. The addition of the triptans has been a breakthrough in the treatment of acute migraine headache. The effectiveness of these medications in relieving the severe pain, disability, and other migraine-associated symptoms has reduced the proportion of patients who require prophylaxis for episodic migraine. Even frequently occurring migraines can be effectively treated with acute medications alone.

Clinicians and patients are now faced with the difficult decision of when to start prophylactic drugs. It is estimated that preventive therapies are used by only 3% to 5% of migraineurs.1 2 Circumstances indicating the need for preventive treatment include: a) two or more disabling headaches per month; b) ineffective symptomatic treatment; c) use of abortive medication more than twice per week; and d) migraines with potential neurological sequelae.3

The mechanisms by which prophylactic drugs reduce migraine frequency and severity remain unknown.4 Many agents appear to have different pharmacological …