If you are taking a calcium channel blocker for high blood pressure, please be aware that there is evidence that long-term use may increase the risk of breast cancer. This does NOT mean that you should stop your medication–but DO ask your doctor if there may be alternative medications, conduct your monthly breast-self-exams (BSEs). annual gynecological examinations and mammograms. Calcium channel blockers include amlodipine (Norvasc), diltiazem (Cardizem, Tiazac), felodipine (Plendil), isradipine (Dynacirc), nifedipine (Adalat, Procardia), nicardipine (Cardene), nimodipine (Nimotop), nisoldipine (Sular) and verapamil (covera-HS, Verelan PM, Calan). Read more here.