Atenolol

Atenolol is a type of sympatholytic drug. Atenolol is a selective β1 antagonist that is clinically used to treat hypertension, angina and cardiac dysrhythmias. Since atenolol is selective to β1 receptor, it only acts on β1 receptors which are located in the heart. As an antagonist, it opposes the effect of sympathetic nervous system activation. Actions of atenolol include the reduction in myocardial contractility and heart rate, hence producing the effect of lowering blood pressure and cardiac output. Side effects of atenolol include cold extremities and exacerbation of cardiac failure, hence this drug is not suitable for patients with heart failure. Since atenolol does not act on β2 receptors, it does not cause bronchoconstriction, therefore allowing asthma patients to use the drug.