Atenolol is a selective β1 receptor antagonist, a drug belonging to the group of beta blockers (sometimes written β-blockers), a class of drugs used primarily in cardiovascular diseases. Introduced in 1976, atenolol was developed as a replacement for propranolol in the treatment of hypertension. It works by slowing down the heart and reducing its workload. Unlike propranolol, atenolol does not pass through the blood–brain barrier to a large extent thus decreasing the incidence of various central nervous system side effects.
Atenolol is one of the most widely used β-blockers in the United Kingdom and was once the first-line treatment for hypertension. The role for β-blockers in hypertension was downgraded in June 2006 in the United Kingdom to fourth-line, as they perform less appropriately or effectively than newer drugs, particularly in the elderly.
Atenolol is used for a number of conditions including: hypertension, angina, long QT syndrome, acute myocardial infarction, supraventricular tachycardia, ventricular tachycardia, and the symptoms of alcohol withdrawal.