A 34-year-old woman complains of headaches that interfere with work. Her first headache episode, approximately 6 years
earlier, was relatively mild. Initially, she experienced attacks only once every 3 to 4 months and managed them effectively
with over-the-counter (OTC) agents. However, in the last 6 months the attacks have become more frequent—they occur at
least twice a month—and are so severe that she misses work.