慢性片頭痛・薬剤の使用過多による頭痛（薬物乱用頭痛）の治療

抄録

Both of chronic migraine (CM) and medication–overuse headache (MOH) are common neurological diseases. They have a great detrimental influence on a patient's life, with a severe impact on socioeconomic functioning and quality of life.

One of the most common causes of migraine chronification is acute medication overuse. On the other hand, MOH is an interaction between a therapeutic agent used excessively and a susceptible patient. Among those with a previous primary headache diagnosis, about 80% of MOH patients have migraine.

All patients with CM should be considered for pharmacological prophylaxis, and the behavioral aspects of therapy should be emphasized. The two prophylactic drugs with the best evidence for efficacy in CM are topiramate and onabotulinumtoxinA. But these therapies currently have not been covered by health insurance in Japan. The options to treat patients with CM are valproic acid, propranolol, lomerizine and amitriptyline. The treatment principles for MOH are : (1) discontinue the overused medication, (2) treat the headache after discontinuing the overused medication, and (3) administer prophylactic medications. Clinical evidence shows that the majority of patients with MOH improve after discontinuation of the overused medication, as does their responsiveness to preventative treatment. Simple advice on the causes and consequences of MOH is an essential part of its management and can be provided with success. Initiation of prophylactic medications at the time of withdrawal or even before withdrawal of overused medications is recommended. Since most of the MOH patients have migraine prior to MOH, valproic acid, lomerizine, propranolol, amitriptyline may be considered as prophylactic medications. As for prognosis, the relapse rate is approximately 30%. Even after discontinuation, patients should be given suitable counseling, and headache diary should be used to confirm the frequency of using triptans, ergotamine and analgesics.