Atenolol: once-daily cardioselective beta blockade for angina pectoris

The physiology, pharmacokinetics and efficacy of atenolol, a cardioselective beta-adrenergic blocking agent, were evaluated in 10 patients with stable angina pectoris in a single-blind, dose-ranging study. After a 1-month control placebo period, atenolol was administered once daily at dosages of 25, 50, 100 and 200 mg for 2-week periods. All patients had fewer anginal attacks and consumed fewer nitroglycerin tablets than mg for 2-week periods. All patients had fewer anginal attacks and consumed fewer nitroglycerin tablets than during the placebo period. Twenty-four-hour ambulatory ECG recordings showed a decrease in mean hourly heart rate throughout the dosing period, with preservation of diurnal variation. Maximal, symptom-limited, treadmill exercise tests performed 3 hours after drug ingestion showed significantly increased exercise time and decreased double products for all doses, but especially with 100-mg and 200-mg doses. Exercise time 24 hours after drug ingestion continued to show a decrease in maximum heart rate and double product, with 100-mg and 200-mg doses again being most effective. Atenolol serum levels correlated with percent reduction in exercise heart rate and increased exercise time. Serum levels rose linearly, with an average elimination half-life of about 10 hours after chronic oral dosing. Thus, atenolol was an effective antianginal agent and suppressed resting and exercise-stressed heart rate for 24 hours after ingestion when given in a 100-mg or 200-mg dose once daily.