[Prophylactic treatment of migraine]

The aim of prophylactic treatment of migraine is to reduce the frequency and severity of migraine attacks. Identifying relevant trigger factors can help reduce the frequency of migraine attacks. The headache diary is useful to identify trigger factors and pattern of headaches and to assess the efficacy of medication. Prophylactic drugs should be considered when attacks are frequent or severe and the acute treatments such as triptans or NSAIDs are not effective. Lomerizine, propranolol, valproate and amitriptyline are useful. Lomerizine is recommended as the first-line prophylactic drug because it is licensed as a preventive drug for migraine in Japan. If attacks has not improved after using a prophylactic drug for 2 months, the drug can be changed to another drug. Propranolol is particularly useful if a patient has hypertension. Amitriptyline is useful if there is associated depression and/or tension-type headache. Valproate is considered if attacks are frequent. Patients should be informed benefits and potential side-effects of the medicine.