A 30-year-old man complains of unilateral headaches. He was diagnosed with migraine headaches at age 24. The headaches did not respond to triptan therapy at that time, but after 6 weeks the headaches resolved. He has had three or four spells of severe headaches since then. Currently his headaches have been present for the past 2 weeks. The headaches start with a stabbing pain just below the right eye. Usually the affected eye feels “irritated” (reddened with increased lacrimation). He saw an optometrist during one of the episodes and a miotic pupil was noted. Each pain lasts from 60 to 90 minutes, but he may have several discrete episodes each day. The neurological examination, including cranial nerve examination, is now normal. What is your best approach to treatment at this time?