Atenolol 100 MG Tablet provided by us, is also used to treat angina and to help people survive a heart attack. Beta blockers, such as atenolol, are a type of medication. It works by preventing some natural substances in your body from acting on your heart and blood arteries, such as epinephrine. It is very effective and safe to use. Your doctor will check your blood pressure and see how your heart reacts, and if necessary, change your dosage.