When coming off beta-blockers, you need to do so gradually and not suddenly stop taking them, for they can cause more harm than help. If you let go of them suddenly, the beta-blocker withdrawal can result in a rise in blood pressure and in patients with heart disease, chest pain, heart attack, and even sudden death. The side effects might last for a week when you stop taking it. But if done under the guidance of a doctor, you can prevent most side effects and gradually get this drug out of your system.