These drugs work to dilate the blood vessels so the blood circulates more freely. They are the same medications given to people with high blood pressure. There are side effects such as headaches and dizziness but these usually go away after the body adjusts to the drug.
CCB’s help with the frequency and severity of attacks as well as reduce the cold feeling. I take the extended release nifedipine, one pill a day. This has been shown to have fewer side effects than the singe dose nifedipine.