hi i am 47year old woman and recently been diagnosed with coronary artery spasm, the cardiologist has put me on tildiem channel blocker, and to take a nitrate, half a tablet every day, i have only took them for 6 days and my side effects are horrendous, the pain in my head, and chest throughout the dat, mainly my head, i have tried to go to work but by three pm i am in agony with the worst headache, can you help and explain why these symptoms are arising and the background to coronary artery spam thank you