Propranolol
"I was on propranolol for about 18 months and went from approximately 20 migraines a month to five. Unfortunately a side effect I developed was cough-variant asthma. Made several visits to the doctor regarding the cough and his suggested that it might be asthma and put me on a daily inhaler. I did some research as I did not want to take a drug to relieve a condition caused by another drug. The side effect was not listed on my propranolol literature, but I found it as a cause for cough-variant asthma. I had to switch to verapamil, which is not quite as effective for my headaches, but my cough is gone."