Influence of the Tohoku-Pacific Ocean Earthquake and Its Aftershocks on the Response to Prophylactic Therapy with Lomerizine in Patients with Migraine in Tokyo: A Retrospective Study

Background: On March 11, 2011, the Tohoku-Pacific Ocean earthquake (magnitude 9.0) struck the eastern part of Japan. Despite being far from the epicenter of the catastrophic earthquake, the effects were strongly felt in Tokyo, and the aftershocks continued for several months. There are no reports regarding the influence of earthquakes on migraine medication. The aim of our study was to determine the impact of earthquakes on prophylactic therapy with lomerizine in patients with migraine in Tokyo. Methods: The study included patients with migraine who were admitted to outpatient clinics in Tokyo between January 2010 and July 2010 or between January 2011 and July 2011 and who were prescribed lomerizine prophylactically for headache by specialists. We investigated clinical factors from the medical records for 26 of these patients. Results: The study population included 10 patients in 2010 and 16 patients in 2011. The frequency of headaches was reduced to under 5 days/month during February in both the groups. Compared to 2010, the frequency of headaches significantly increased in 2011 in March, April and May. Conclusion: Patients with migraine were sensitive to exposure to the earthquake and their headaches worsened despite successful prophylactic treatment with lomerizine before the Tohoku-Pacific Ocean earthquake.