ABSTRACT
Prophylactic treatment is mainly intended to reduce the frequency of migraine attacks. It is usually proposed to patients who suffer from two or more attacks per month. It should also be considered in patients who suffer from less frequent, but prolonged, disabling attacks with a poor response to abortive treatment, and who consider that their quality of life is reduced between attacks. Excessive intake of acute medication, more than twice a week, is a strong indication for prophylactic treatment. In order to obtain a good compliance to treatment, the patient must be informed of the expected efficacy of the drugs, and of their most frequent side effects. Thus, the choice of a prophylactic drug is made together with the patient. Based on the results of published controlled trials, the main prophylactic drugs are some betablockers, methysergide, pizotifene, oxetorone, flunarizine, amitriptyline, NSAIDs, and sodium valproate. Some less evaluated drugs such as aspirin, DHE, indoramine, verapamil, may be useful. Other substances such as riboflavin and new antiepileptic dugs are being evaluated. The choice of the drug to start with depends on several considerations. The first step is to make sure that there are no contra indications, and no possible interaction with the abortive medications. Then, possible side effects will be taken into account, for example, weight gain is a problem for most young women and patients who practice sports may not tolerate betablockers. Associated pathologies have to be checked. For example, a hypertensive migraine sufferers may benefit from betablockers; in a patient who suffers both from migraine and tension type headaches or from depression, amitriptyline is the first choice drug. The type of migraine should also be considered; for instance, in frequent attacks with aura, aspirin is recommended and betablockers avoided. In most cases, prophylaxis should be given as monotherapy, and it is often necessary to try successively several drugs before finding the most appropriate one. Doses should be increased gradually, in order to reach the recommended daily dose, only if tolerance permits. The treatment efficacy has to be assessed after 2 or 3 months, during which the patient must keep a headache diary. If the drug is judged ineffective, an overuse of symptomatic medications should be checked, as well as a poor compliance, either of which may be responsible. In case of a successful treatment, it should be continued for 6 or 12 months, and then, one should try to taper off the dose in order to stop the treatment or at least to find the minimum active dose. Relaxation, biofeedback, stress coping therapies, acupuncture are also susceptible to be effective in migraine prophylaxis.