It possible to die from on overdose of betablocker. They work on the conduction system of the heart. Too much can cause life threatening slow heart beat and low blood pressure.
If you fell your pulse dropping and your chest feels funny and there is shortness of breath you should seek medical attention. It is important to do so quickly so you don't risk having a heart attack.
Common Uses: This medicine is a beta-adrenergic blocking agent (beta-blocker) used to treat high blood pressure, alone or with other medicines. It is also used for the long-term treatment of chest pain and to treat certain types of heart failure. It may also be used for other conditions as determined by your doctor.