Aten 100 Tablet works by blocking the effects of some chemicals on your heart and blood vessels. It slows down your heart rate and helps the heartbeat with less force. This lowers your blood pressure and helps in reducing your risk of having a stroke, a heart attack, other heart problems, or kidney problems in the future. This medicine needs to be taken regularly to be effective, so keep taking it even if you feel well. Do not stop without talking to your doctor.