I went from having 2 to 3 migraines/severe nausea, a month to 8 or 9, when I began using Imitrex. My Dr. said it was a coincidence.
That went on for 20 years. I was given 6 shots a month so either suffered in bed, or went to the ER. for an additional shot. Then a cardiologist put me on Cardizem for AFIB (which was caused by a diuretic). My migraines decreased and became less painful and some months I have been headache free so continued taking it. I was taking 250 mg. a day, without any obvious side effects. I have tried to stop taking it a few times and the migraines come back within a week or so. That dose is now taken every other day, and migraines are infrequent, maybe one a month and usually go away with OTC meds.