Effects of long-term, once-daily administration of atenolol on ambulatory blood pressure of hypertensive patients.

We measured intraarterial, ambulatory blood pressure over a 24-h period in 12 subjects 24--63 years (mean 47.6) of age with newly diagnosed untreated hypertension. Measurements were performed both before and after 2--9 months of once-daily treatment with atenolol, a cardioselective beta-adrenoceptor antagonist. Significant reductions in arterial pressure (p less than 0.005) during treatment with atenolol (dose range 50--200 mg) were observed over the full 24-h period.