Atenolol (brand name Tenormin) is a drug used to treat high blood pressure, certain types of chest pain and certain irregular heartbeats. Atenolol belongs to a class of drugs called beta blockers, named for their action in the body. The drug binds to beta receptors found in various places in the body and blocks them from being stimulated. This blocking effect leads to a decrease in blood pressure and heart rate, and relieves some types of chronic chest pain. A few properties of atenolol make it better suited for certain situations than other beta blockers.
Cardioselectivity
Beta receptors are found in both the heart as well as the large airways in the chest. Atenolol blocks the stimulation of these receptors, particularly in the heart, leading to a slower heart rate and more relaxed muscle. Blockade of the beta receptors in the airways cause bronchoconstriction, or tightening of the airways, which can precipitate an asthma or COPD attack. Atenolol preferentially binds to beta receptors in the heart as opposed to in the airways. Thus, atenolol at low doses can be used safely in patients with a known history of lung disease if their blood pressure cannot to be controlled by other medications.
Doesn't Affect Renal Function
Atenolol, unlike similar drugs, does not act on peripheral beta receptors in the kidneys. For those with pre-existing kidney disease, atenolol may be a better choice if beta blockade is necessary for blood pressure control as it does not affect kidney function.
Once-a-day Dosing
Atenolol, unlike some other drugs in its class, stays in circulation and blocks beta receptors for a longer period of time. Therefore, it needs to be taken only once a day in order to be effective.
