If I could only have one drug in my pharmacopeia, what would it be?

An antibiotic? A pain reliever? A happy pill? Keep guessing…

During my Saturday clinic, I saw a man I had done a physical on two weeks before.

He told me he had suffered from daily headaches for several years and was popping over-the-counter medications just about daily to no avail; he clearly had developed rebound headaches on top of his frequent migraines.