Drugs and progression from episodic to chronic migraine

To prevent progression from episodic to chronic migraine with analgesic overuse it is recommended that migraine patients with severe and frequent attacks receive: 1. an effective acute treatment, 2. early initiation of prophylaxis [1]. Unfortunately, available drugs for acute and prophylactic treatments of migraine have limited efficacy, just in more severe patients. Twenty percent of migraine women experience migraine attacks in at least two thirds of their menstrual cycles. These attacks are more impairing, longer lasting, and have more associated symptoms, greater severity, susceptibility to relapse, and resistance to treatment than nonmenstrual episodes. Severe and prolonged attacks are associated with the risk of becoming chronic. It follows that many of the women with chronic migraine and medication overuse who address headache centers suffered from menstrual episodic migraine at the onset. The strong impact of menstrual migraine on chronification is demonstrated by the fact that its improvement by hormonal therapy is related with either the conversion of chronic migraine to an episodic pattern or a significant reduction of medication overuse [2]. Yet, for this so common and serious disorder there is no specific highly effective pharmacological therapy. With prophylactic treatments only 50% - 65% of patients can expect a reduction of 50% of attacks. Prophylactic drugs do not significantly change the severity and length of the attacks. In addition, the choice among the drugs recommended is empirical. After a physician has prescribed, by trial and error, the third or fourth prophylactic drug without benefits, it may be too late: migraine may have become chronic and complicated by medication overuse. Actually, patients with chronic headache have a higher prevalence of the use of migraine prophylactic medications compared to those with episodic headache. Therefore, even if the advances achieved in the treatment of migraine in the last 20 years are to be appreciated, they are not yet sufficient. If they were decisive, the prevalence of chronic headache and analgesic overuse would probably decrease over time. It remains instead stable. Overall, these data indicate that more effective acute and prophylactic treatments are needed and markers of response must be identified, to allow choosing soon the optimal drug for the individual patient. It has been suggested that chronic migraine with medication overuse is a marker of refractory. Maybe, in many patients medication overuse is a signal of the limitations of currently available drugs to treat more severe migraine. 1. Evers S, Marziniak M (2010) Clinical features, pathophysiology, and treatment of medication-overuse headache. Lancet Neurol 9:391-401. 2. Calhoun A, Ford S (2008) Elimination of menstrual-related migraine beneficially impacts chronification and medication overuse. Headache 48:1186-1193.