Role of a third generation calcium antagonist in the management of hypertension

Results of a 14-Week, Multicenter, Prospective, Randomized, Open-Label, Noninferiority Clinical Trial Comparing the Antihypertensive Effect and Edema Incidence of Lacidipine and Amlodipine in Older Korean Patients with Mild-to-Moderate Hypertension

Background

It has been shown that administration of lacidipine markedly reduces systolic blood pressure in elderly patients with hypertension without increasing the incidence of cardiovascular events and total mortality. But in Korea, there were no available data about the effectiveness and safety of lacidipine.

Objectives

The goal of our study was to compare the effect of lacidipine and amlodipine besylate on sitting systolic blood pressure (SBP) and edema regression time as primary parameters, and sitting diastolic blood pressure (DBP) and tolerability as a secondary parameter in patients with hypertension.

Method

This was a prospective, randomized, open-label, noninferiority study in which patients received 14 weeks of treatment with either lacidipine or amlodipine besylate. Patients aged 55 to 80 years having uncomplicated, mild-to-moderate essential hypertension (SBP 140 to <180 mm Hg or DBP ≥90 mm Hg) and receiving no antihypertensive medications during the 2 weeks before randomization were randomly assigned to receive lacidipine or amlodipine. The incidence of adverse events was also assessed.

Results

In total, 315 patients (154 men, mean age 67.6 years) were included in the intent-to-treat analysis and randomly assigned to receive lacidipine (n = 162) or amlodipine besylate (n = 153); 286 patients were included in the per-protocol analysis (n = 150 for lacidipine, n = 136 for amlodipine) (12 in the lacidipine group and 17 in the amlodipine group were excluded from the per-protocol analysis due to consent withdrawal or protocol violation). There were no differences in demographic profiles between the 2 groups. Mean (SD) SBP changes at 14 weeks were −18.9 (12.7) mm Hg in the lacidipine group and −20.6 (12.4) mm Hg in the amlodipine group (P >0.05). Because the 1-sided 95% CI for the difference in mean SBP changes between groups (−4.18 to 0.72) was within the pre-specified lower limit (−5 mm Hg), lacidipine was considered noninferior to amlodipine. There were no differences in mean edema regression time and in mean DBP changes. These results were consistent in the isolated systolic hypertension subgroup analysis. The overall incidence of clinical adverse events was comparable between the 2 groups (ie, 7.4% in the lacidipine group and 11.1% in the amlodipine group [P >0.05]). The most common adverse events were headache and facial flushing (5 out of 162 patients [3.1%] in the lacidipine group and 11 out of 153 patients [7.2%] in the amlodipine group].

Conclusions

Fourteen weeks of lacidipine treatment significantly reduced blood pressure in older Korean patients with mild-to-moderate hypertension. The efficacy of lacidipine was not inferior to that of amlodipine besylate and tolerability was comparable between the 2 treatment groups. ClinicalTrials.gov identifier: NCT00460915.

Design, synthesis, and biological testing of thiosalicylamides as a novel class of calcium channel blockers

The current research aimed to investigate the importance of the heterocyclic ring system in the structure of the cardiovascular drug diltiazem for its calcium channel blocking activity. The manuscript describes the design, synthesis, and biological testing of a total of 10 S-(p-methoxybenzyl), N-substituted thiosalicylamides as a series of non-cyclic compounds derived from diltiazem's structure. The new compounds maintained all diltiazem pharmacophores except the thiazepine ring system. In vitro evaluation of the new series for calcium channel blocking effects revealed moderate activities with IC50 values in the range of 4.8-56.0 microM. The data suggest that the ring system is not essential for activity; however, its absence leads to a considerable drop of activity relative to that of diltiazem (IC50=0.3 microM). Compounds of the current series showed optimum activity when the aliphatic alkyl chain on the salicylamide nitrogen is part of a piperidine or piperazine ring system substituted at the terminal nitrogen with a benzyl group.

Effects of amlodipine and lacidipine on heart rate variability in hypertensive patients with stable angina pectoris and isolated left ventricular diastolic dysfunction

OBJECTIVE

To estimate the influence of therapy with amlodipine (A) or lacidipine (L) on heart rate variability (HRV) time and frequency domain parameters in hypertensive patients with stable angina pectoris and isolated left ventricular diastolic dysfunction.

METHODS

After a 1-week washout period, the patients were randomized to receive amlodipine 10 mg (30 patients) or lacidipine 6 mg (30 patients) once-daily for 4 weeks. HRV parameters were determined over a period of 24 h, echocardiography and exercise test were performed before and after treatment.

RESULTS

All HRV time domain parameters after applying amlodipine did not change significantly. A reliable decrease only of the root mean square of differences between adjacent normal-to-normal intervals (RMSSD)-32.9 +/- 13 vs. 27.5 +/- 9-was noticed after treatment with lacidipine. In the lacidipine group, the change of RMSSD negatively correlated with the extent of ST segment depression during exercise testing (R = -0.43; P < 0.05). Both drugs reduced total power (A, 2234 +/- 1270 vs. 1813 +/- 889; L, 2205 +/- 1151 vs. 1825 +/- 896; P < 0.01), very low (A, 1451 +/- 733 vs. 1143 +/- 534; L, 1413 +/- 759 vs. 1213 +/- 616; P < 0.05), and low frequency power (A, 610 +/- 459 vs. 447 +/- 321; L, 569 +/- 323 vs. 442 +/- 241; P < 0.01). After amlodipine, high frequency power remained unchanged, whereas low-high frequency ratio decreased (4.54 +/- 1.72 vs. 3.77+/-1.73; P < 0.05). After lacidipine, high frequency power decreased (178.8 +/- 153.2 vs. 132.1 +/- 79.3; P < 0.05), whereas the ratio of low frequency to high frequency did not change.

CONCLUSIONS

Amlodipine and lacidipine reduce the influence of humoral control and sympathetic autonomic nervous system activity. The autonomic balance becomes shifted toward the increased vagal activity only by amlodipine.

Ionization, lipophilicity, and molecular modeling to investigate permeability and other biological properties of amlodipine

This paper uses a recent approach toward drug discovery, in which in silico tools and experimental data are combined together to study the structural features of amlodipine and their relevance in the peculiar pharmacodynamic and pharmacokinetic profiles of this long acting calcium antagonist. Results reveal for amlodipine two families of conformers (folded and extended) but also demonstrate that protonation is the predominant factor governing amlodipine intermolecular interactions among which ionic forces play a major role.

Differential time effect profiles of amlodipine, as compared to valsartan, revealed by ambulatory blood pressure monitoring, self blood pressure measurements and dose omission protocol

Amlodipine and valsartan are once-daily antihypertensive agents. To date, no comparison between these agents given as monotherapies was reported. This study was aimed to evaluate the therapeutic coverage and safety of amlodipine and valsartan in mild-to-moderate hypertensive patients. Multicenter, double-blind, randomized, comparative study. After a 4-week placebo wash-out period, 246 outpatients with office diastolic blood pressure 95 < or = DBP < or =110 mmHg and systolic blood pressure (SBP) < 180 mmHg, in addition to a mean daytime SBP and/or DBP > 135/85 mmHg on 24-h ambulatory blood pressure monitoring (ABPM), were randomly allocated to once-daily amlodipine 5-10 mg or valsartan 40-80 mg, for 12 weeks. In a subgroup of patients, 48-h ABPM were performed at the end of the treatment period. Dose omission was simulated by a single-blind placebo dosing. The primary efficacy end-point was the 24-h trough office BP after 12 weeks of active therapy. The reductions in 24-h trough BP were more pronounced in amlodipine compared with valsartan group as well in office [SBP: -17.8 +/- 10.9 vs. -14.6 +/- 11.2, P = 0.025, DBP: -12.7 +/- 7.2 vs. -10.9 +/- 7.8 mmHg, P = 0.06) as in ambulatory BP (SBP/DBP: -13.0 +/- 13.7/-10.8 +/- 9.1 vs. -7.2 +/- 19.4/-4.9 +/- 13.4 mmHg, P < 0.05). Forty-eight hours after the last active dose, the slope of the morning BP surge (4-9 h) was less steep with amlodipine vs. valsartan [DBP (P < 0.04), SBP (n.s.)]. Ankle edema were more often reported in amlodipine group. These results suggest a superior BP lowering and a longer duration of action with amlodipine compared with valsartan.

Effect of different dihydropyridine-type Ca2+ antagonists on left ventricle hypertrophy and coronary changes in spontaneously hypertensive rats

Effects of treatment with equi-hypotensive doses of first-, second-, and third-generation dihydropyridine-type Ca2+ channel blockers on hypertension-dependent left ventricle hypertrophy and coronary vascular changes were assessed in spontaneously hypertensive rats (SHRs) by quantitative microanatomic techniques. Male SHRs were treated for 12 weeks with equi-hypotensive doses of nifedipine, isradipine, manidipine, amlodipine, and lercanidipine. Untreated age-matched normotensive Wistar-Kyoto rats were used as a reference group. Compounds investigated decreased to a similar extent systolic pressure in SHRs. Increased cardiocyte size (hypertrophy), development of necrosis and fibrosis areas, and increased thickness of coronary arteries with luminal narrowing were observed in control SHRs. Pharmacologic treatment countered hypertension-dependent left ventricle and coronary artery changes in SHRs. Manidipine, amlodipine, and lercanidipine displayed a similar activity, whereas nifedipine and isradipine were less potent. These findings support observations that antihypertensive treatment counters hypertension-related left ventricle and coronary changes. The observation of a different effect of Ca2+ antagonists tested suggests the possibility of a more favorable cardiac profile exerted by some dihydropyridines. The evaluation of specific properties of dihydropyridines on hypertensive end-organ damage may contribute to better choices depending on clinical situations.

Manidipine: a review of its use in hypertension

Manidipine is a dihydropyridine calcium antagonist, which causes systemic vasodilation by inhibiting the voltage-dependent calcium inward currents in smooth muscle cells. The resulting reduction in blood pressure (BP) in patients with hypertension is maintained over 24 hours. Manidipine 10 to 40 mg once daily for 4 weeks significantly lowered office BP from baseline and compared with placebo, and significantly reduced 24-hour BP compared with placebo in patients with essential hypertension in a well controlled trial. The decline in BP was maintained over 24 hours (trough to peak BP ratios were >50%) without disturbing the circadian BP pattern. BP reductions with therapeutic dosages of manidipine were maintained for up to 1 year in noncomparative trials. The BP-lowering capacity of manidipine 5 to 20 mg/day appears to be similar to that of other calcium antagonists with which it has been compared in randomised double-blind and nonblind trial. In a well controlled short term trial, manidipine 10 mg daily significantly decreased trough sitting BP compared with placebo in elderly patients with mild to moderate essential hypertension. Decreases in BP were maintained for up to 3 years of treatment. The drug (10 or 20 mglday) also significantly lowered sitting BP from baseline in patients with hypertension and type 2 diabetes mellitus in randomised, long term comparative trials. In general, the observed reduction in BP with manidipine was similar to that observed with amlodipine, enalapril or delapril. The effects of manidipine on urinary albumin excretion (UAE) have not been clearly demonstrated in clinical trials in this patient group. BP was also reduced with manidipine in patients with impaired glucose tolerance. Manidipine was well tolerated in clinical trials, with most adverse effects related to vasodilation. Commonly reported events included ankle oedema, headache. palpitation. flushing, dizziness, rash and fatigue. Manidipine appears to have less potential for pedal oedema than amlodipine.

CONCLUSIONS

Manidipine has shown antihypertensive efficacy and appears to be well tolerated in adult and elderly patients with mild or moderate essential hypertension. The BP-lowering effects of the drug in patients with hypertension and type 2 diabetes mellitus or impaired glucose tolerance were not associated with any adverse metabolic effects. The effects of manidipine on UAE in this patient group remain unclear. Manidipine provides an additional treatment option for patients for whom dihydropyridine calcium antagonists are appropriate. Manidipine is a dihydropyridine calcium antagonist, which causes systemic vasodilation by inhibiting the voltage-dependent calcium inward currents in smooth muscle cells. The resulting reduction in blood pressure (BP) in patients with hypertension is maintained over 24 hours. Manidipine 10 to 40mg once daily for 4 weeks significantly lowered office BP from baseline and compared with placebo, and significantly reduced 24-hour BP compared with placebo in patients with essential hypertension in a well controlled trial. The decline in BP was maintained over 24 hours (trough to peak BP ratios were >50%) without disturbing the circadian BP pattern. BP reductions with therapeutic dosages of manidipine were maintained for up to 1 year in non-comparative trials. The BP-lowering capacity of manidipine 5 to 20 mg/day appears to be similar to that of other calcium antagonists with which it has been compared in randomised double-blind and nonblind trial. In a well controlled short term trial, manidipine 10 mg daily significantly decreased trough sitting BP compared with placebo in elderly patients with mild to moderate essential hypertension. Decreases in BP were maintained for up to 3 years of treatment. The drug (10 or 20 mg/day) also significantly lowered sitting BP from baseline in patients with hypertension and type 2 diabetes mellitus in randomised, long term comparative trials. In general, the observed reduction in BP with manidipine was similar to that observed with amlodipine, enalapril or delapril. The effects of manidipine on urinary albumin excretion (UAE) have not been clearly demonstrated in clinical trials in this patient group. BP was also reduced with manidipine in patients with impaired glucose tolerance. Manidipine was well tolerated in clinical trials, with most adverse effects related to vasodilation. Commonly reported events included ankle oedema, headache. palpitation. flushing, dizziness, rash and fatigue. Manidipine appears to have less potential for pedal oedema than amlodipine.

CONCLUSIONS

Manidipine has shown antihypertensive efficacy and appears to be well tolerated in adult and elderly patients with mild or mo