Effects of the long-acting calcium channel blocker barnidipine hydrochloride on 24-h ambulatory blood pressure

Effects of New Calcium Channel Blocker, Azelnidipine, and Amlodipine on Baroreflex Sensitivity and Ambulatory Blood Pressure

The effect of dihydropyridine calcium channel blocker (CCB) on baroreflex sensitivity (BRS) is not well described. We studied the effect of a new CCB, azelnidipine, compared with amlodipine, on BRS and ambulatory blood pressure (BP) in newly diagnosed untreated hypertension. This study was a prospective, randomized, and open-label study. We randomized patients to either azelnidipine or amlodipine treatment. Azelnidipine 8 to 16 mg (average 14.5 mg) and amlodipine 2.5 to 7.5 mg (average 4.9 mg) were used to lower the clinical BP <140/90 mm Hg. BRS, evaluated by the spontaneous and the Valsalva methods, and clinical and ambulatory BP were evaluated at baseline and after 13 weeks of each treatment. A total of 47 patients (age 53.1 +/- 10.8 years, 51% male), 26 in the azelnidipine group and 21 in the amlodipine group, completed the study. For baseline and after therapy respectively, both Valsalva-BRS (4.8 +/- 1.7 vs. 8.4 +/- 3.1 msec/mm Hg, P = 0.001) and spontaneous-BRS (5.5 +/- 2.5 vs. 8.2 +/- 5.6 msec/mm Hg, P = 0.019) were increased by azelnidipine, but amlodipine did not change them. Clinical and awake BPs were similarly reduced by each drug therapy. In conclusion, BRS was increased by azelnidipine therapy, but not by amlodipine therapy. This differential effect may be important in cardiovascular risk reduction.

Strategies Against High Blood Pressure in the Early Morning

Acute myocardial infarction and cerebrovascular disease reportedly show peak onset in the early morning, when blood pressure increases. The increase of blood pressure, or morning surge, may result from increased sympathetic activity reactive to arousal. The circadian pattern of vascular events is considered to be related to the morning surge in blood pressure, sympathetic activity, and hypercoagulability. Although there is no direct evidence indicating a causal relationship between the morning surge in blood pressure and vascular complications, it may be postulated that morning blood pressure surge is a factor which affects hypertensive complications. There may be two possible approaches to morning blood pressure surge; the pharmacodynamic and pharmacokinetic approach. On the basis of pharmacodynamics, drugs with adrenergic alpha-blocking actions are usually selected. From a pharmacokinetic view, it is essential to maintain blood concentration of a drug at the critical early morning period. On this point, use of long acting agents, changes in drug regimen and the development of a chronobiological system has been studied, with many studies reporting successful results in lowering morning blood pressure. Further study whether such kinds of treatments improve long term outcomes in hypertensive patients are desired.

The Efficacy and Tolerability of Barnidipine Hydrochloride in Thai Patients with Hypertension

This open-label, blinded study was performed to evaluate the efficacy and tolerability of barnidipine at a titrated dose of 10 − 15 mg once daily for 8 weeks in the treatment of essential hypertension in 40 Thai patients. ‘Office’ blood pressure (BP) and 24-h ambulatory BP measurements were recorded. A systolic BP/ diastolic BP (SBP/DBP) reduction of 18.0 ± 13.6/9.1 ± 6.6 mmHg was obtained. The full response rate among patients with systolic and diastolic hypertension was 63% using either SBP or DBP criteria, and 54% using both SBP and DBP criteria. One of the two patients with isolated systolic hypertension had a full response, and the BP in two of the three patients with isolated diastolic hypertension was normalized. The trough-to-peak ratio and smoothness index for SBP/DBP were acceptable (0.76 ± 0.63/0.55 ± 0.26 and 1.2 ± 0.4/1.2 ± 0.3, respectively). In conclusion, once-daily barnidipine monotherapy provides effective 24-h BP control and is generally well tolerated in ambulatory patients.