Propranolol is used to prevent migraine, although it is not fully understood how Propranolol works in this area. Beta-blockers work by blocking beta receptors that are found in various parts of the body. Beta-blockers work by blocking beta receptors that are found in various parts of the body. Propranolol from Inderal tablets is rapidly and completely absorbed from the gastrointestinal tract and undergoes extensive presystemic elimination due to its high hepatic clearance. The heart at any level of effort by blocking catecholamine induced increases in the heart rate, low blood pressure and heart failure.