THE BEDTIME DOSING OF BARNIDIPINE HYDROCHLORIDE RESTORES CIRCADIAN RHYTHM IN NONDIPPER HYPERTENSIVE PATIENTS: PP.33.303

Abstract

Nondipper pattern (blunted or absent nocturnal decrease of blood pressure) is associated with increased cerebral, cardiovascular and renal events. Therefore, the normalization of blood pressure (BP) circadian rhythm is an important goal of antihypertensive treatment. Aim of this study was the evaluation of the effect of a bedtime administration of the calcium channel blocker (CCB) barnidipine hydrochloride on blood pressure dipping status of treated hypertensive subjects. Patients were selected according to the presence of a nighttime fall in systolic BP < 10% of daytime systolic BP on a previous ambulatory BP monitoring (ABPM). The reproducibility of non-dipping status was confirmed through a second 24-h ABP monitoring in 48 patients (mean age 59 ± 16 years, 20 females), whose treatment did no include a CCB. On top of the previous stable treatment regimen, a bedtime (10.00–11.00 pm) 10 mg dosing of barnidipine was added to all subjects. At study entry, mean daytime ABP was 135/83 ± 7/8 mmHg, while mean nighttime was ABP 131/82 ± 7/7 mmHg. After 12 weeks of add-on treatment with barnidipine a 24-h ABPM was repeated. At study end, mean daytime ABP resulted slightly reduced (126/79 ± 7/6, −9/4 mmHg), while mean nighttime ABP decreased in overt fashion (115/74 ± 6/6, −16/8 mmHg). The decrease in systolic and diastolic mean ABP induced by barnidipine bedtime administration resulted statistically significant (daytime systolic p < 0.05, daytime diastolic p < 0.05; nigttime systolic p < 0.025, nighttime diastolic p < 0.025; Student's t test for paired data; two-sided p, α level p < 0.05). Among the 48 nondipper patients 27 (56%) of them showed complete normalization of circadian rhythm. Add-on treatment with barnidipine resulted generally well tolerated. Two patients developed mild symptomatic diurnal hypotension and 4 individuals presented mild leg oedema. In conclusion, in treated hypertensive patients presenting nondipper pattern, bedtime dosing of the CCB barnidipine (added to previous stable treatment regimen) significantly reduced nighttime systolic and diastolic mean ABP and, in 56% of the subjects restored the previously altered circadian rhythm.