If you are a woman and you take calcium channel blockers like amlodipine (Norvasc) or nicardipine (Cardene) to manage your high blood pressure, you could be putting yourself at serious risk of developing breast cancer. This is according to a new study recently published in the journal, JAMA Internal Medicine, which found that women who take such drugs have about a 250 percent increased risk of developing some of the most common types of breast cancer compared to other women.