The pharmacologic treatment of migraine

For the past two years our increasing knowledge of migraine’s biogenesis has been paralleled by an explosion of new therapies unprecedented in their biologic selectivity and clinical effectiveness. While these medications provide us with a potent arsenal of weaponry for combating migraine, all possess at least some imperfections, and their inappropriate use may make a bad situation worse. In this article, we will discuss the issues of acute migraine treatment, prevention of migraine attacks and suppression of chronic migraine, emphasizing the use of medications.

Despite the advances that have been made, pharmacologic treatment of migraine remains a process of educated trial and error. Come to one of one of our headache clinics, and you will find after a few weeks that although their personalities may vary dramatically, virtually all migraine patients offer one of surprisingly few histories in describing their headache syndromes. Despite the similarities
in the histories provided by migraineurs, there is no one abortive or prophylactic drug that is universally effective for all patients. Presumably this reflects the heterogeneous nature of migraine’s underlying biology; it well may be that there are dozens, hundreds or even thousands of genetic permutations that yield these relatively few clinical presentations, and each of those genetic
polymorphisms may produce a different type of neurochemical abnormality. The resulting biologic variation implies that only some proportion of migraineurs will respond to a drug that possesses a relatively specific mechanism of action, acting only to modify a certain type neurochemical abnormality.

What are the different subtypes of migraine? The majority of migraineurs have migraine without aura, but a significant minority (again, approximately 20%) have at least occasional aura with their attacks; a tiny percentage report migraine attacks that predominantly involve aura only. In terms of headache frequency, there are those patients who experience less than 15 days of headache per month (episodic migraine), those who experience 15 or more headache days per month but not daily headache (frequent episodic migraine) and those whose headaches are daily (chronic daily headache/chronic migraine); the last group is subdivided into those who are aggravating their chronic daily headache (CDH) headache syndrome through overuse of acute medications and those who are not.

Drug therapy for migraine is divided into treatment that is abortive (ie, for acute headache only) versus treatment that is prophylactic (i.e., intended for prevention of attacks).