Q. Patient suffers from intermittent searing headaches over the left eye with associated rhinorrea and lacrimation and a small pupil. The headaches can last an hour and are so severe that the patient would "do anything" to make the pain go away. They typically occur a few times per day over several weeks at the beginning of the fall. Which of the following is used as a first-line treatment in the abortive management of these headaches?