Daytime-selective antihypertensive activity of celiprolol

Day-activity rhythms of heart rate and blood pressure are thought to be med iated mainly through the sympathetic nervous system and may have greater am plitudes in patients with hypertension owing to increased daytime and large ly normal nighttime values. Drug-induced nighttime hypotension in patients with chronic hypertension has been associated with the precipitation of car diac failure and a fall in cerebral flow. The authors examined the effects of a single dose and of a 4-week treatment with different classes of antihy pertensive drugs on ambulatory blood pressure (ABP) in 10 patients with mil d hypertension. Data were assessed by polynomial analysis (Harvard Graphics 3). A single oral dose of enalapril 10 mg, amlodipine 5 mg, carvedilol 25 mg, and celiprolol 200 mg produced a mean reduction of 24-hour ABP compared to placebo of, respectively, 24/11, 11/5, 13/6, and 12/5 mm Hg (p values b etween < 0.02 and < 0.001). With enalapril, amlodipine, and carvedilol, bet ween-subject variability contributed significantly to the overall variabili ty in the measurements (p values between 0.05 and 0.01 versus zero), wherea s with celiprolol this was not so. Although the beta blockers reduced dayti me blood pressures similarly to the ACE inhibitor or the calcium channel bl ocker, they did not reduce nighttime blood pressures. These results were co nfirmed by an 8-week crossover trial comparing enalapril 10 mg daily with c eliprolol 200 mg daily in the same group of patients. The authors conclude (1) that beta blockers produce a more stable reduction of blood pressure in patients with mild hypertension less affected by presser effects through t he sympathetic nervous system; (2) that beta blockers, unlike ACE inhibitor s and calcium channel blockers, do not give rise to nighttime hypotension i n this category of patients; and (3) that the selective beta blocker celipr olol may even perform better in these respects than the nonselective beta b locker carvedilol.