Comparison between cilnidipine and amlodipine besilate with respect to proteinuria in hypertensive patients with renal diseases

Evaluation of cilnidipine-loaded self-micro-emulsifying drug delivery system (SMEDDS) by quantification of comparative pharmacokinetic parameters using validated LC-ESI-MS/MS bioanalytical method and pharmacodynamic assessment

OBJECTIVE

Regardless of having desired therapeutic properties many of the recently approved drugs are removed from the developmental pipeline for their clinical use due to low solubility and permeability. Conventional dosage forms are found relatively unsuitable for achieving desired pharmacokinetic and pharmacodynamics profiles. Cilnidipine is 1,4 dihydropyridine derivative calcium channel blocker used for the treatment of hypertension.

METHOD

The aim and objective of this study was to develop a precise and significant method in LC-MS/MS for quantification of pharmacokinetic parameters of a cilnidipine-loaded self-micro-emulsifying drug delivery system in rat plasma and simultaneously assessed pharmacodynamic characters in comparison with the marketed cilnidipine tablet. Another potential aim of this study is to reduce the dose of the drug in order to counter the dose-dependent toxicities related to chronic use. In the present study, the parent and product ion of cilnidipine was m/z 491.3\237.1.

RESULT

The plasma was extracted by protein precipitation technique. The calibration standard concentrations were 1.875, 3.75, 7.50, 15.00, 30.00, 60.00ng/mL and LLOQ, low-quality control, middle-quality control and high-quality control were 1.87, 5.62, 22.50, 45.00ng/mL, respectively. The mobile phase composition was 0.1% formic acid in Milli Q water with 10mM Ammonium acetate as an aqueous solvent and 0.1% formic acid in methanol as an organic solvent. Following oral administration of optimized formulation Cmax (peak plasma concentration) was achieved 21.02±3.17ng/mL at 0.866±0.11h (Tmax), whereas in the case of marketed tablet Cmax (peak plasma concentration) was achieved 10.16±0.89ng/mL at 0.93±0.11h (Tmax).

DISCUSSION

The in-vivo characterizations of the optimized SMEDDS showed significantly better pharmacokinetic parameters in Wistar rats and showed almost 2.4 times enhanced relative bioavailability as compared to the marketed tablet of cilnidipine which was observed to be correlating to our findings with noninvasive blood pressure parameter of Wistar rats.

Blood Pressure Reducing Potential and Renoprotective Action of Cilnidipine Among Hypertensive Patients Suffering From Chronic Kidney Disease: A Meta-Analysis

Hypertension is a risk factor for cardiovascular diseases which also causes progressive kidney damage leading to chronic kidney disease (CKD), so the rate of progression of CKD can be controlled by reducing blood pressure (BP). Many anti-hypertensive drugs are available. Cilnidipine is a new-generation calcium channel blocker (CCB). This meta-analysis is aimed to generate pooled evidence about the effectiveness of cilnidipine as an anti-hypertensive and to explore its reno-protective actions. Pubmed, Scopus, Cochrane Library, and Google Scholar were searched from January 2000 to December 2022 to include the studies. The pooled mean difference, along with 95% CI, was computed using Revman 5.4.1 software (Revman International, Inc., New York City, New York). The Cochrane risk-of-bias assessment tool was used for bias assessment. This meta-analysis was registered in PROSPERO with Reg. no. CRD42023395224. This meta-analysis included seven studies with 289 participants in the intervention group and 269 in the comparator group, and were selected from Japan, India, and Korea. Systolic blood pressure (SBP) was significantly reduced in cilnidipine treated group among hypertensives with CKD subjects weighted mean difference (WMD) was 4.33, and the 95% confidence interval (CI) was 1.26 to 7.31 as compared to the other group. Cilnidipine also shows a significant reduction in proteinuria with WMD 0.61 and 95% CI 0.42 to 0.80. Both groups were similar in adverse drug reactions (ADR). Cilnidipine is a more effective anti-hypertensive as compared to Amlodipine or other CCBs, mainly in reducing SBP. Besides this, cilnidipine also shows better reno-protective action because it also significantly reduces proteinuria in such patients.

Renal Function in Hypertensive Patients Receiving Cilnidipine and L-Type Calcium Channel Blockers: A Meta-Analysis of Randomized Controlled and Retrospective Studies

Nearly 65%-95% of chronic kidney disease (CKD) patients have hypertension. Calcium-channel blockers are the first-line drugs for the treatment of hypertension, including hypertension with diabetes. This study aims to estimate the effect of an L-type calcium channel blocker (CCB), cilnidipine, on the renal function of hypertensive patients. Randomized control trials were selected from PubMed, Embase, Google Scholar, China National Knowledge Infrastructure (CNKI), Science Direct, Elton B. Stephens Company (EBSCO), Springer, Ovid, Cochrane Library, Medline, VIP, and Wanfang databases (from the date of databases' establishment till January 2022). Data were independently evaluated following the Cochrane risk-of-bias tool. The changes in serum creatinine (SCr), urinary protein excretion (UPE), urinary protein/creatinine ratio (UPCR), and estimated glomerular filtration rate (eGFR) before and after treatment, in percentages, were extracted for the meta-analysis. The mean difference (MD) and a CI of 95% were determined using RevMan 5.3 software. A total of 11 studies were analyzed. The standardized mean difference (SMD) between cilnidipine and L-type CCBs was -0.022, suggesting a reduced SCr with cilnidipine. For UPCR, the SMD value is 1.28. Although cilnidipine reduced UPCR in all four studies, the L-type CCBs reported a slight increase in UPCR. For eGFR, the SMD value was found to be 0.693. Cilnidipine had a more favorable effect on eGFR when compared to the L-type CCBs. While cilnidipine had similar effects on SCr to that of L-type CCBs, cilnidipine showed greater improvement in UPCR, UPE, and eGFR values.

N-type calcium channel and renal injury

Accumulating evidences indicated that voltage-gated calcium channels (VDCC), including L-, T-, N-, and P/Q-type, are present in kidney and contribute to renal injury during various chronic diseases trough different mechanisms. As a voltage-gated calcium channel, N-type calcium channel was firstly been founded predominately distributed on nerve endings which control neurotransmitter releases. Since sympathetic nerve is distributed along renal afferent and efferent arterioles, N-type calcium channel blockade on sympathetic nerve terminals would bring renal dynamic improvement by dilating both arterioles and reducing glomerular pressure. In addition, large body of scientific research indicated that neurotransmitters, such as norepinephrine, releases by activating N-type calcium channel can trigger inflammatory and fibrotic signaling pathways in kidney. Interestingly, we recently demonstrated that N-type calcium channel is also expressed on podocytes and may directly contribute to podocyte injury in denervated animal models. In this paper, we will summarize our current knowledge regarding renal N-type calcium channels, and discuss how they might contribute to the river that terminates in renal injury.

Efficacy of Cilnidipine (L/N-type Calcium Channel Blocker) in Treatment of Hypertension: A Meta-Analysis of Randomized and Non-randomized Controlled Trials

INTRODUCTION

 Hypertension is one of the most common cardiovascular diseases, and the prevalence of hypertension continues to rise across the globe. National and international guidelines recommend angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), calcium channel blockers (CCBs), diuretics, and beta-blockers for the management of hypertension. CCBs are among the most used antihypertensive medications and Cilnidipine is a newer dihydropyridine CCB shown to have a prolonged antihypertensive property.

OBJECTIVE

 This meta-analysis of comparative randomized and non-randomized clinical trials evaluated the effect of Cilnidipine monotherapy or combination therapy on systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse rate (PR) over 48 weeks of therapy.

STUDY DESIGN

 PubMed (MEDLINE) and Google scholar databases were searched to identify studies designed to evaluate the effects of Cilnidipine in the treatment of hypertensive patients. The study criteria for inclusion into the meta-analysis were all prospective, randomized, and non-randomized clinical studies published till March 2021, studies published in a peer-reviewed journal, the inclusion of patients with hypertension, assessment of blood pressure and heart rate, and a follow-up of four weeks or longer. The initial search identified 82 potential articles; of these, 24 met the inclusion criteria. Studies with <4 weeks treatment period and those not having a CCB were excluded.

OUTCOMES

 Change in SBP, DBP, and PR from baseline at the end of therapy compared between the Cilnidipine and other CCB's.

RESULTS

Cilnidipine caused a significant reduction (p<0.05) in SBP, DBP, and PR at end of therapy, whereas the reduction in SBP, DBP, and PR with Cilnidipine was similar to other CCB's (p>0.05). The results of this meta-analysis revealed that there were no significant differences in the efficacy in the treatment of hypertensive patients with Cilnidipine and the other therapies.

CONCLUSION

 Cilnidipine has similar anti-hypertensive effects compared with other first-line antihypertensive drugs commonly used in practice. We recommend Cilnidipine as a novel first-line CCB for the management of hypertension either as a monotherapy or as a combination therapy.

An N-/L-type calcium channel blocker, cilnidipine, suppresses autonomic, electrical, and structural remodelling associated with atrial fibrillation

AIMS

Autonomic dysfunction can promote atrial fibrillation (AF) and results from AF-related remodelling. N-type Ca2+-channels (NTCCs) at sympathetic nerve terminals mediate Ca2+-entry that triggers neurotransmitter release. AF-associated remodelling plays an important role in AF pathophysiology but the effects of NTCC inhibition on such remodelling is unknown. Here, we investigated the ability of a clinically available Ca2+-channel blocker (CCB) with NTCC-blocking activity to suppress the arrhythmogenic effects of AF-promoting remodelling in dogs.

METHODS AND RESULTS

Mongrel dogs were kept in AF by right atrial tachypacing at 600 bpm. Four groups were studied under short-term AF (7 days): (i) Shams, instrumented but without tachypacing (n = 5); (ii) a placebo group, tachypaced while receiving placebo (n = 6); (iii) a control tachypacing group receiving nifedipine (10 mg orally twice-daily; n = 5), an L-type CCB; and (iv) a cilnidipine group, subjected to tachypacing and treatment with cilnidipine (10 mg orally twice-daily; n = 7), an N-/L-type CCB. With cilnidipine therapy, dogs with 1-week AF showed significantly reduced autonomic changes reflected by heart rate variability (decreases in RMSSD and pNN50) and plasma norepinephrine concentrations. In addition, cilnidipine-treated dogs had decreased extracellular matrix gene expression vs. nifedipine-dogs. As in previous work, atrial fibrosis had not yet developed after 1-week AF, so three additional groups were studied under longer-term AF (21 days): (i) Shams, instrumented without tachypacing or drug therapy (n = 8); (ii) a placebo group, tachypaced while receiving placebo (n = 8); (iii) a cilnidipine group, subjected to tachypacing during treatment with cilnidipine (10 mg twice-daily; n = 8). Cilnidipine attenuated 3-week AF effects on AF duration and atrial conduction, and suppressed AF-induced increases in fibrous-tissue content, decreases in connexin-43 expression and reductions in sodium-channel expression.

CONCLUSIONS

Cilnidipine, a commercially available NTCC-blocking drug, prevents AF-induced autonomic, electrical and structural remodelling, along with associated AF promotion.

Comparison of effects of L/N-type and L-type calcium channel blockers on post-infarct cardiac remodelling in spontaneously hypertensive rats

Hypertension and coronary events are becoming more prevalent in aging societies, and myocardial infarction usually occurs in calcium channel blocker (CCB)-treated hypertensive patients. We herein compared the effects of cilnidipine, an L/N-type CCB and amlodipine, an L-type CCB, on post-infarct left ventricular (LV) remodelling in spontaneously hypertensive rats (SHRs). Male SHRs were subjected to 30 minutes of left coronary artery occlusion followed by reperfusion (MI group). The administration of cilnidipine (10 mg/kg/d; MI + Cil group) or amlodipine (10 mg/kg/d; MI + Aml group) was initiated one week before surgery and continued for five weeks. Both CCBs decreased blood pressure. Four weeks after surgery, cilnidipine, but not amlodipine, attenuated LV dilatation, fractional shortening impairments, end-diastolic pressure elevations, and tau elongation. In the non-infarct region, myocyte hypertrophy and brain natriuretic peptide (BNP) mRNA levels were similarly attenuated by both CCBs. On the other hand, interstitial fibrosis, the mRNA expression of collagen type III and transforming growth factor (TGF) β and immunohistological TGF β protein expression in the non-infarct region were reduced more in the MI + Cil group than in the MI + Aml group. Additionally, elevated angiotensin-converting enzyme activity and interstitial noradrenaline concentrations in the non-infarct region were reduced by cilnidipine. These results suggest that cilnidipine reduced cardiac noradrenaline concentrations and inhibited the renin-angiotensin system, which attenuated post-infarct remodelling more than amlodipine in hypertensive rats.

Reduction in microalbuminuria by calcium channel blockers in patients with type 2 diabetes mellitus and hypertension-A randomized, open-label, active-controlled, superiority, parallel-group clinical trial

BACKGROUND

It has been suggested that renoprotection with calcium channel blockers (CCBs) may differ. This study aimed to compare the anti-proteinuric effect of different CCBs in patients with type 2 diabetes (T2D).

METHODS

A multicentre, randomized, open-label, active-controlled study was performed in seven centres in Korea. A total of 74 patients with T2D and microalbuminuria treated with renin-angiotensin system (RAS) blockers were randomized to a cilnidipine 10 mg treatment (n=38) or amlodipine 5 mg treatment (n=36).

RESULTS

Urine albumin to creatinine ratio (ACR) reduction was similar between the two groups at 12 weeks (-53.0±123.2 mg/g in cilnidipine group and -35.7±83.6 mg/g in amlodipine group, P=.29) or 24 weeks (-57.3±106.9 mg/g in cilnidipine group and -20.0±110.4 mg/g in amlodipine group, P=.24). In a subgroup analysis, cilnidipine treatment showed a larger ACR reduction than amlodipine treatment at 12 weeks (-84.7±106.8 mg/g in cilnidipine group and -9.5±79.2 mg/g in amlodipine group, P=.01) and 24 weeks (-84.0±111.7 mg/g in cilnidipine group and 14.6±119.4 mg/g in amlodipine group, P=.008), particularly in patients with a longer duration of diabetes more than 10 years.

CONCLUSIONS

Cilnidipine did not show any additional anti-albuminuric effect compared with amlodipine in patients with T2D and microalbuminuria treated with an RAS blocker. However, the anti-albuminuric effect of cilnidipine might differ according to the duration of diabetes.

Comparison of Plasma Levels of Renin, Vasopressin and Atrial Natriuretic Peptide in Hypertensive Amlodipine Induced Pedal Oedema, Non-Oedema and Cilnidipine Treated Patients

INTRODUCTION

Amlodipine is a third generation dihydropyridine group of calcium channel blocker and having an excellent antihypertensive profile. Pedal Oedema (PE) is the major drawback of amlodipine therapy and the incidence of Amlodipine Induced Pedal Oedema (AIPE) has been found significantly high. Several neurohumoral factors influence the incidence of oedema.

AIM

We aimed to compare the plasma levels of renin, vasopressin and atrial natriuretic peptide in hypertensive AIPE, non-oedema and cilnidipine treated patients.

MATERIALS AND METHODS

The present prospective, interventional study was conducted on 104 mild to moderate hypertensive patients (52 patients in each group), after due consideration of eligibility criteria. Plasma Renin (PR), Vasopressin (VAS), and the Atrial Natriuretic Peptide (ANP) was estimated by ELISA test and compared between the AIPE, Amlodipine Treated Non-Oedema (ATNE) in Phase I, and AIPE and Cilnidipine Treated (CT) Groups in Phase II.

RESULTS

The clinical and demographic parameters were matched. PR was significantly high in AIPE group than the ATNE, and it was significantly reduced after one month follow up with the substitution of cilnidipine. The median (IQR) value of PR was 4.87 (3.58, 6.63), 3.50 (1.44, 5.47) and 2.66 (1.02, 5.66) ng/ml in AIPE, ATNE, CT group respectively. VAS was significantly high in AIPE group than ATNE, and it significantly reduced after one month follow up with CT group. The median (IQR) value of vasopressin was 6.78 (2.55, 9.16), 2.58 (1.61, 5.73) and 2.50 (1.23, 5.00) ng/ml in AIPE, ATNE and CT groups respectively. There was no significant difference seen in plasma ANP levels between the groups. The p-value was <0.05 which is statistically significant.

CONCLUSION

The AIPE may not be volume overload or fluid retention; it may be due to persistent raise in adrenergic activity followed chronic amlodipine therapy. Cilnidipine relatively suppresses the sympathetic activity, and completely resolves the AIPE by significantly reducing PR and VAS levels. ANP did not show a difference between groups. Cilnidipine is the suitable alternative antihypertensive drug for AIPE patients.

A Comparative Study on Clinical and Biochemical Parameters in Amlodipine and Cilnidipine Treated Hypertensive Patients

INTRODUCTION

Hypertension is a major health issue worldwide. Calcium Channel Blockers (CCBs) are the most commonly used antihypertensive agents. CCBs act on voltage-dependent calcium channels and they were categorized into two subclasses, Dihydropyridine (DHP) and non-Dihydropyridine (non-DHP) derivative. Amlodipine is a third generation L-type of DHP and Cilnidipine is a novel L/N-type of DHP CCB, both drugs have excellent pharmacological profiles with the unique actions.

AIM

To study the clinical and biochemical profile in Amlodipine and Cilnidipine treated mild to moderate hypertensive patients.

MATERIALS AND METHODS

The present study was a cross-sectional study. A total of 140 mild to moderate hypertensive patients (HTN classified according to Joint National Committee-8 (JNC-8) HTN guideline), 70 were in Amlodipine group (Group-A), and other 70 patients were in Cilnidipine group (Group-B). Group-A receiving Tab Amlodac 5 mg/day and Group-B receiving Tab Cilacar 10 mg/day, and both the group receiving respective medications since more than six months. Patients enrolled into the study with due consideration of eligibility criteria. Demographic, clinical and biochemical parameters were noted and compared.

RESULTS

Demographic parameters are matched, there was no significant difference seen between two study groups. Systolic and Diastolic Blood Pressure (SBP and DBP) showed a significant difference (p<0.001). There was no significant difference in pulse rate between the two groups, both QT/QTc showed statistically significant difference (p<0.001). The biochemical parameters like serum creatinine, albumin, globulin, total protein, serum Na⁺, fractional excretion of Na⁺, serum osmolality, vanillyl mandelic acid, were compared between two study groups, there was no significant difference seen between the two groups.

CONCLUSION

The Amlodipine and Cilnidipine both are equally effective antihypertensive drugs. Cilnidipine treated group showed more reduction in blood pressure than the Amlodipine treated group and there was no significant change in heart rate between the two groups. Cilnidipine group showed comparatively shortened QT/QTc interval than the Amlodipine group.

Ablation of the N-type calcium channel ameliorates diabetic nephropathy with improved glycemic control and reduced blood pressure

Pharmacological blockade of the N- and L-type calcium channel lessens renal injury in kidney disease patients. The significance of specific blockade of α1 subunit of N-type calcium channel, Ca_v2.2, in diabetic nephropathy, however, remains to be clarified. To examine functional roles, we mated Ca_v2.2^−/− mice with db/db (diabetic) mice on the C57BLKS background. Ca_v2.2 was localized in glomeruli including podocytes and in distal tubular cells. Diabetic Ca_v2.2^−/− mice significantly reduced urinary albumin excretion, glomerular hyperfiltration, blood glucose levels, histological deterioration and systolic blood pressure (SBP) with decreased urinary catecholamine compared to diabetic Ca_v2.2^+/+ mice. Interestingly, diabetic heterozygous Ca_v2.2^+/− mice also decreased albuminuria, although they exhibited comparable systolic blood pressure, sympathetic nerve activity and creatinine clearance to diabetic Ca_v2.2^+/+ mice. Consistently, diabetic mice with cilnidipine, an N-/L-type calcium channel blocker, showed a reduction in albuminuria and improvement of glomerular changes compared to diabetic mice with nitrendipine. In cultured podocytes, depolarization-dependent calcium responses were decreased by ω-conotoxin, a Ca_v2.2-specific inhibitor. Furthermore, reduction of nephrin by transforming growth factor-β (TGF-β) in podocytes was abolished with ω-conotoxin, cilnidipine or mitogen-activated protein kinase kinase inhibitor. In conclusion, Ca_v2.2 inhibition exerts renoprotective effects against the progression of diabetic nephropathy, partly by protecting podocytes.

Comparison of the cardioprotective and renoprotective effects of the L/N-type calcium channel blocker, cilnidipine, in adriamycin-treated spontaneously-hypertensive rats

Cilnidipine is an L/N-type calcium channel blocker (CCB). The effects of cilnidipine on N-type channels give it unique organ-protective properties via the suppression of hyperactivity in the sympathetic nervous system (SNS) and renin-angiotensin-aldosterone system (RAAS). In the present study, we compared the effects of cilnidipine and amlodipine (an L-type CCB) on cardiac and renal functions in spontaneously-hypertensive rats injected with adriamycin (ADR). After the weekly administration of ADR for 3 weeks, spontaneously-hypertensive rats were orally administered cilnidipine (20 mg/kg per day), amlodipine (3 mg/kg per day), or vehicle once daily for 4 weeks. A control group received saline rather than ADR, followed by vehicle for 4 weeks. Cilnidipine and amlodipine produced similar reductions in blood pressure after 4 weeks. Cilnidipine ameliorated ADR-induced heart and kidney damage, whereas amlodipine slightly improved cardiac echocardiographic parameters, but did not protect against ADR-induced renal damage. Cilnidipine (but not amlodipine) suppressed the reflex SNS and RAAS hyperactivity caused by their antihypertensive effects. Furthermore, cilnidipine and amlodipine treatment decreased the urinary levels of adrenocortical hormones. The protective effects of cilnidipine against ADR-induced renal and cardiac dysfunction might be associated with its blockade of N-type calcium channels, in addition to its pleiotropic actions, which include the inhibition of the RAAS.

Reduction of microalbuminuria in type-2 diabetes mellitus with angiotensin-converting enzyme inhibitor alone and with cilnidipine

The aim of our study was to find out the antiproteinuric effect of enalapril angiotensin-converting enzyme (ACE inhibitor) alone or in combination with cilnidipine in patients with type-2 diabetes mellitus. The study was conducted on 71 patients with type-2 diabetes mellitus patients with hypertension and microalbuminuria. They were divided into two groups randomly as follows: Group I (enalaprilalone, n = 36) and Group II (enalapril with cilnidipine, n = 35). In both the groups, baseline 24 h urinary albumin was estimated and was repeated every 3 months upto 1-year. After 1-year follow-up, reduction in microalbuminuria was found to be greater in Group II. In Group I microalbuminuria came down by 25.68 ± 21.40 while in Group II it reduced by 54.88 ± 13.84 (P < 0.001). We conclude that in diabetic population, cilnidipine has an additive effect in microalbuminuria reduction over and above the well-proven effect of ACE inhibitors.

The organ-protective effect of N-type Ca(2+) channel blockade

The six subtypes of voltage-dependent Ca(2+) channels (VDCCs) mediate a wide range of physiological responses. N-type VDCCs (NCCs) were originally identified as a high voltage-activated Ca(2+) channel selectively blocked by omega-conotoxin (ω-CTX)-GVIA. Predominantly localized in the nervous system, NCCs are key regulators of neurotransmitter release. Both pharmacological blockade with ω-CTX-GVIA and, more recently, mice lacking CNCNA1B, encoding the α1B subunit of NCC, have been used to assess the physiological and pathophysiological functions of NCCs, revealing in part their significant roles in sympathetic nerve activation and nociceptive transmission. The evidence now available indicates that NCCs are a potentially useful therapeutic target for the treatment of several pathological conditions. Efforts are therefore being made to develop effective NCC blockers, including both synthetic ω-CTX-GVIA derivatives and small-molecule inhibitors. Cilnidipine, for example, is a dihydropyridine L-type VDCC blocking agent that also possesses significant NCC blocking ability. As over-activation of the sympathetic nervous system appears to contribute to the pathological processes underlying cardiovascular, renal and metabolic diseases, NCC blockade could be a useful approach to treating these ailments. In this review article, we provide an overview of what is currently known about the physiological and pathophysiological activities of NCCs and the potentially beneficial effects of NCC blockade in several disease conditions, in particular cardiovascular diseases.

The sympathetic nervous system as a target for the treatment of hypertension and cardiometabolic diseases

The regulation of blood pressure by the sympathetic nervous system is reviewed with an emphasis on the role of the sympathetic nervous system in the development and maintenance of hypertension. Evidence from patients and animal models is summarized. Because it is clear that there is a neural contribution to many types of human hypertension and other cardiometabolic diseases, the case is presented for a renewed emphasis on the development of sympatholytic approaches for the treatment of hypertension and other conditions associated with hyperactivity of the sympathetic nervous system.

Additive effects of cilnidipine, an L-/N-type calcium channel blocker, and an angiotensin II receptor blocker on reducing cardiorenal damage in Otsuka Long-Evans Tokushima Fatty rats with type 2 diabetes mellitus

Cilnidipine (Cil), which is an L-/N-type calcium channel blocker (CCB), has been known to provide renal protection by decreasing the activity of the sympathetic nervous system (SNS) and the renin–angiotensin system. In this study, we compared the effects of the combination of Cil and amlodipine (Aml), which is an L-type CCB, with an angiotensin (Ang) II receptor blocker on diabetic cardiorenal damage in spontaneously type 2 diabetic rats. Seventeen-week-old Otsuka Long-Evans Tokushima Fatty rats were randomly assigned to receive Cil, Aml, valsartan (Val), Cil + Val, Aml + Val, or a vehicle (eight rats per group) for 22 weeks. Antihypertensive potencies were nearly equal among the CCB monotherapy groups and the combination therapy groups. The lowering of blood pressure by either treatment did not significantly affect the glycemic variables. However, exacerbations of renal and heart failure were significantly suppressed in rats administered Cil or Val, and additional suppression was observed in those administered Cil + Val. Although Val increased the renin–Ang system, Aml + Val treatment resulted in additional increases in these parameters, while Cil + Val did not show such effects. Furthermore, Cil increased the ratio of Ang-(1–7) to Ang-I, despite the fact that Val and Aml + Val decreased the Ang-(1–7) levels. These actions of Cil + Val might be due to their synergistic inhibitory effect on the activity of the SNS, and on aldosterone secretion through N-type calcium channel antagonism and Ang II receptor type 1 antagonism. Thus, Cil may inhibit the progression of cardiorenal disease in type 2 diabetes patients by acting as an N-type CCB and inhibiting the aldosterone secretion and SNS activation when these drugs were administered in combination with an Ang II receptor blocker.

The fourth-generation Calcium channel blocker: cilnidipine

Several classes of antihypertensive agents have been in clinical use, including diuretics, α-blockers, β-blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin II type 1 receptor blockers (ARB), and organic calcium channel blockers (CCBs). All these drugs are being currently used in the treatment of Hypertension & various disease conditions of the heart either alone or in combination. Cilnidipine is a new antihypertensive drug distinguished from other L-type Ca(2+) channel blockers or even other antihypertensives, which will be useful for selection of antihypertensive drugs according to the pathophysiological condition of a patient.

Switching to an L/N-type calcium channel blocker shows renoprotective effects in patients with chronic kidney disease: the Kyoto Cilnidipine Study

OBJECTIVE

This open-label, randomized controlled trial investigated the effects of cilnidipine, an L/N-type calcium channel blocker (CCB), in patients with chronic kidney disease (CKD).

METHODS

Sixty patients with CKD and well-controlled hypertension being treated with a renin- angiotensin system (RAS) inhibitor and an L-type CCB (L-CCB) were randomly assigned either to switch from the L-CCB to cilnidipine after a 4-week observation period or to continue with L-CCB treatment. Blood pressure, heart rate and renal function were monitored for 12 months. Data were available for analysis from 50 patients: 24 from the cilnidipine group and 26 from the L-CCB group.

RESULTS

Blood pressure was well controlled in both groups. After 12 months, proteinuria and heart rate were significantly decreased in the cilnidipine group, but proteinuria increased and heart rate remained unchanged in the L-CCB group. There was a significant positive correlation between the percentage changes in proteinuria and heart rate.

CONCLUSIONS

Cilnidipine has antihypertensive effects equivalent to those of L-CCBs. In patients with CKD, proteinuria can be decreased by switching from an L-CCB to cilnidipine, thereby improving renal function.

Excellent tolerance to cilnidipine in hypertensives with amlodipine - induced edema

Background:

Ankle edema is a common adverse effect of amlodipine, an L-type calcium channel blocker (CCB). Cilnidipine is a newer L/N-type CCB, approved for treatment of essential hypertension.

Aim:

This study was designed to determine whether cilnidipine can produce resolution of amlodipine-induced edema while maintaining adequate control of hypertension.

Materials and Methods:

A prospective study was performed on 27 patients with essential hypertension with amlodipine-induced edema. Concomitant nephropathy, cardiac failure, hepatic cirrhosis, or other causes of edema, and secondary hypertension were excluded by appropriate tests. Amlodipine therapy was substituted in all the cases with an efficacy-equivalent dose of cilnidipine. Clinical assessment of ankle edema and measurement of bilateral ankle circumference, body weight, blood pressure, and pulse rate were performed at onset of the study and after 4 weeks of cilnidipine therapy.

Results:

At completion of the study, edema had resolved in all the patients. There was a significant decrease in bilateral ankle circumference and body weight (P < 0.001). There was no significant change in mean arterial blood pressure and pulse rate.

Conclusions:

Therapy with cilnidipine resulted in complete resolution of amlodipine-induced edema in all the cases without significant worsening of hypertension or tachycardia. Cilnidipine is an acceptable alternative antihypertensive for patients with amlodipine-induced edema.

Comparison of the antialbuminuric effects of L-/N-type and L-type calcium channel blockers in hypertensive patients with diabetes and microalbuminuria: the study of assessment for kidney function by urinary microalbumin in randomized (SAKURA) trial

OBJECTIVE

To clarify whether the L-/N-type calcium channel blocker (CCB) cilnidipine is more renoprotective than the L-type CCB amlodipine in patients with early-stage diabetic nephropathy.

METHODS

In this prospective, multicenter, open-labeled, randomized trial, the antialbuminuric effects of cilnidipine and amlodipine were examined in renin-angiotensin system (RAS) inhibitor-treated patients with hypertension (blood pressure [BP]: 130-180/80-110 mmHg), type 2 diabetes, and microalbuminuria (urinary albumin to creatinine [Cr] ratio [UACR]: 30-300 mg/g).

RESULTS

Patients received cilnidipine (n = 179, final dose: 10.27 ± 4.13 mg/day) or amlodipine (n = 186, 4.87 ± 2.08 mg/day) for 12 months. Cilnidipine and amlodipine equally decreased BP. The UACR values for the cilnidipine and amlodipine groups were 111.50 ± 138.97 and 88.29 ± 63.45 mg/g, respectively, before treatment and 107.93 ± 130.23 and 89.07 ± 97.55 mg/g, respectively, after treatment. The groups showed similar changes for the natural logarithm of the UACR, serum Cr, and estimated glomerular filtration rate.

CONCLUSIONS

Cilnidipine did not offer greater renoprotection than amlodipine in RAS inhibitor-treated hypertensive patients with type 2 diabetes and microalbuminuria.

Comparison of the effects of cilnidipine and amlodipine on cardiac remodeling and diastolic dysfunction in Dahl salt-sensitive rats

OBJECTIVE

The L/N-type calcium channel blocker (CCB) cilnidipine suppresses sympathetic nerve activity and has a superior renoprotective effect compared with L-type CCBs such as amlodipine. The cardioprotective action of cilnidipine has remained largely uncharacterized, however. We have now investigated the effects of cilnidipine, in comparison with amlodipine, on cardiac pathophysiology in rats with salt-sensitive hypertension.

METHODS

Dahl salt-sensitive rats fed a high-salt diet from 6 weeks of age were treated with vehicle (LVH group), amlodipine (3 mg/kg per day), or cilnidipine (3 mg/kg per day) from 7 to 11 weeks.

RESULTS

The salt-induced increase in SBP apparent in LVH rats was attenuated to a similar extent by treatment with amlodipine or cilnidipine. The two drugs also similarly inhibited the development of left ventricular (LV) hypertrophy. However, cilnidipine attenuated the increase in relative wall thickness as well as ameliorated LV perivascular and interstitial fibrosis and diastolic dysfunction to a greater extent than did amlodipine. In addition, cilnidipine treatment was associated with greater inhibition of cardiac oxidative stress, inflammation, and renin-angiotensin system (RAS) gene expression. The decrease in cardiac norepinephrine content apparent in LVH rats was similarly inhibited by both drugs.

CONCLUSIONS

Cilnidipine attenuated LV fibrosis and diastolic dysfunction as well as LV concentricity to a greater extent than did amlodipine in Dahl salt-sensitive rats. The superior cardioprotective action of cilnidipine is likely attributable, at least in part, to the greater antioxidant and anti-inflammatory effects associated with inhibition of cardiac RAS gene expression observed with this drug.

Renoprotective and antioxidant effects of cilnidipine in hypertensive patients

Cilnidipine, an L/N-type calcium channel blocker (CCB), has been reported to have more beneficial effects on proteinuria progression in hypertensive patients than amlodipine, an L-type CCB. The N-type calcium channel blockade that inhibits renal sympathetic nerve activity might reduce glomerular hypertension by facilitating vasodilation of the efferent arterioles. However, the precise mechanism of the renoprotective effect of cilnidipine remains unknown. Because cilnidipine exerted significantly higher antioxidant activity than amlodipine in cultured human mesangial cells, we hypothesized that cilnidipine might exert a renoprotective effect by suppressing oxidative stress. A total of 35 hypertensive patients receiving a renin-angiotensin system inhibitor were randomly assigned to a cilnidipine (n=18; 10 mg per day cilnidipine titrated to 20 mg per day) or amlodipine (n=17; 5 mg per day amlodipine titrated to 10 mg per day) group; the target blood pressure (BP) was set at 130/85 mmHg. After 6 months of treatment, systolic and diastolic BPs were significantly reduced in both of the groups, without any significant difference between the groups. The urinary albumin, 8-hydroxy-2'-deoxyguanosine (OHdG) and liver-type fatty-acid-binding protein (L-FABP) to creatinine ratios significantly decreased in the cilnidipine group (P<0.05) compared with those in the amlodipine group. The reductions in urinary albumin, 8-OHdG and L-FABP were not correlated with the change in systolic BP. In conclusion, cilnidipine, but not amlodipine, ameliorated urinary albumin excretion and decreased urinary 8-OHdG and L-FABP in the hypertensive patients. Cilnidipine probably exerts a greater renoprotective effect through its antioxidative properties.

Antialbuminuric advantage of cilnidipine compared with L-type calcium channel blockers in type 2 diabetic patients with normoalbuminuria and microalbuminuria

We evaluated the antialbuminuric advantage of cilnidipine, an N/L-type calcium channel blocker (CCB), compared with L-type CCBs in diabetic patients with normoalbuminuria and microalbuminuria. The study was a multicenter, non-randomized crossover trial. Participants were 90 type 2 diabetic patients exhibiting either normo- or microalbuminuria, and undergoing CCB treatment for ≥6 months prior to study entry. The CCB at the time of entry was continued for the first 6 months (Period 1). Treatment was subsequently switched from cilnidipine to an L-type CCB, or vice versa, for the second 6-month observation period (Period 2). During Period 1, the L-type CCB group showed a significant increase of urinary albumin excretion (UAE) over time, while the cilnidipine group showed no significant elevation. During Period 2, switching of the treatment from the L-type CCB to cilnidipine resulted in significant reduction of the UAE, whereas switching from cilnidipine to the L-type CCB resulted in no significant change in the UAE. This study demonstrated that the antialbuminuric effect of Cilnidipine, but not the L-type CCBs, was sustained even in patients treated for a long time. In addition, the antialbuminuric effect can be anticipated after switching from an L-type CCB to cilnidipine, but not vice versa.

Design and rationale of the study of assessment for kidney function by urinary microalbumin in randomized (SAKURA) trial

Recently, it has been demonstrated that L-/N-type calcium channel blockers (CCBs), cilnidipine, but not L-type CCB, decreased urinary protein in renin-angiotensin system (RAS), inhibitor-treated hypertensive patients with macroproteinuria. However, the antiproteinuric effect of cilnidipine was weaker in diabetic patients than in nondiabetic patients with macroproteinuria. This may be due to the fact that diabetic neuropathy was also developed in patients with advanced diabetic nephropathy because L-/N-type CCB has been considered to exert its renoprotetive effects through sympatholytic action. If so, the antiproteinuric effect of cilnidipine may be potent in patients with early stages of diabetic nephropathy. To elucidate our hypothesis, we designed a multi-center, open-labeled, randomized trial to compare the antialbuminuric effect between cilnidipine and amlodipine in RAS inhibitor-treated hypertensive (blood pressure [BP]: 130-180/80-110 mmHg) patients with type 2 diabetes and microalbuminuria (urinary albumin/creatinine [Cr] ratio: 30-300 mg/g). The primary study endpoint is the change in the urinary albumin/Cr ratio after a 1-year treatment. Enrollment began in April 2008 and was completed in March 2010. A total of 367 patients were randomly allocated to receive cilnidipine or amlodipine. At baseline, study subjects had 63.3± 8.5 years of age, 145.9 ± 12.2/80.8 ± 10.0 mmHg of BP, 101.0 ± 111.6 mg/g of urinary albumin/Cr. The trial is expected to show whether cilnidipine can exert an antialbuminuric effect in RAS inhibitor-treated hypertensive patients with early stages of diabetic nephropathy.

Beneficial effects of L- and N-type calcium channel blocker on glucose and lipid metabolism and renal function in patients with hypertension and type II diabetes mellitus

It has been proved that cilnidipine has N-type calcium channels inhibitory activity as well as L-type calcium channels and inhibits excessive release of norepinephrine from the sympathetic nerve ending. This study was undertaken to compare the efficacy of amlodipine (an inhibitor of L-type calcium channels) and cilnidipine (an inhibitor of both L-type and N-type calcium channels) in patients with hypertension and type II diabetes mellitus. Seventy-seven hypertensive patients were divided into two groups according to presence/absence of type II diabetes mellitus. In these two groups of patients, the effects of amlodipine and cilnidipine on glucose and lipid metabolism and renal function were compared. As for glucose and lipid metabolism, homeostasis model assessment insulin resistance (HOMA-R) level in the non-diabetic group and triglyceride in the diabetes group were significantly lower with cilnidipine than with amlodipine. As regards renal function in the diabetic group, estimated glomerular filtration rate (eGFR) was significantly higher and urinary albumin/creatinine ratio was significantly lower with cilnidipine than with amlodipine. Cilnidipine which inhibits N-type calcium channels is more useful for patients with hypertension and diabetes mellitus from its effects on glucose and lipid metabolism and renal function.

Effects of an N-type calcium antagonist on angiotensin II-renin feedback

BACKGROUND

Interrupting the renin-angiotensin system (RAS) with an angiotensin II receptor blocker (ARB) has been found to induce RAS overactivation. In this study, we investigated the effect of 2 calcium channel blockers (CCBs), cilnidipine (L-/N-type CCB) and amlodipine (L-type CCB), on the RAS activation induced by an ARB in a strain of spontaneously hypertensive rats (SHR/Izm, 10 weeks of age).

METHODS

Rats intravenously catheterized for blood collection were randomly divided into groups that were administered the vehicle, the ARB valsartan or valsartan combined with one of the 2 CCBs. Their blood and kidneys were collected 270 min after administration.

RESULTS

Valsartan increased the plasma angiotensin II (Ang II) level in a dose-dependent manner. Cilnidipine suppressed the increase in plasma renin activity and plasma Ang II levels induced by valsartan, but amlodipine did not. Combined administration of cilnidipine, but not amlodipine, and valsartan significantly reduced the noradrenaline content in the renal cortex.

CONCLUSIONS

The results of this study suggest that the suppressive effect of cilnidipine on the valsartan-induced increase in RAS activity can be partly explained by its sympatholytic action mediated by N-type calcium channel blockade, and that combined administration of cilnidipine and valsartan might provide a synergistic therapeutic effect.

Comparison between the antiproteinuric effects of the calcium channel blockers benidipine and cilnidipine in combination with angiotensin receptor blockers in hypertensive patients with chronic kidney disease

AIMS

Benidipine, an L-/T-type calcium channel blocker, dilates renal efferent and afferent arterioles and reduces glomerular pressure; therefore, it may exert renoprotective effects. We conducted an open-labeled randomized trial to compare the effects of benidipine with cilnidipine in hypertensive patients with chronic kidney disease (CKD).

METHODS

The patients who were already being treated with angiotensin receptor blockers (ARBs) received one of the following treatment regimens: benidipine at a dose of 2 mg/day that was increased up to a dose of 8 mg/day (benidipine group; n=118) or cilnidipine at a dose of 5 mg/day that was increased up to a dose of 20 mg/day (cilnidipine group; n=115).

RESULTS

After 12 months of treatment, we observed a significant and comparable reduction in the systolic and diastolic blood pressure in both groups. The urinary protein:creatinine ratio was significantly decreased in both groups after 3 months of treatment and thereafter; however, the difference between both groups was not significant after 12 months of treatment. Benidipine exerted an antiproteinuric effect to a greater extent than cilnidipine in patients with diabetes.

CONCLUSION

The addition of benidipine as well as cilnidipine reduces urinary protein excretion in hypertensive patients with CKD who are already being administered ARBs.

L/N-type calcium channel blocker cilnidipine ameliorates proteinuria and inhibits the renal renin-angiotensin-aldosterone system in deoxycorticosterone acetate-salt hypertensive rats

Cilnidipine, an N/L-type calcium channel blocker, has been reported to inhibit sympathetic nerve activity and has a greater renoprotective effect than L-type calcium channel blockers. To investigate the hypothesis that cilnidipine might ameliorate advanced hypertensive nephropathy and inhibit the renal renin-angiotensin-aldosterone system, cilnidipine (1 mg per kg per day) or amlodipine (1 mg per kg per day) was administered to uninephrectomized deoxycorticosterone (DOCA)-salt hypertensive rats (DOCA-salt) for 4 weeks by gavage. Although the blood pressure in the DOCA-salt group was higher than that of control, neither cilnidipine nor amlodipine had any effect on the increase in blood pressure in the DOCA-salt group. The DOCA (40 mg per kg per week, subcutaneously (s.c.)) and salt (1% NaCl in drinking water) treatment significantly aggravated the levels of urinary protein excretion and creatinine clearance and increased glomerulosclerosis and collagen deposition in the tubulointerstitial area of the kidney. These effects were attenuated by cilnidipine treatment. Reverse transcription-polymerase chain reaction analysis revealed that the renal expression of mRNA for collagen I/IV and transforming growth factor-β was enhanced in the DOCA-salt group and that the overexpression of these molecules was suppressed by cilnidipine. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-derived superoxide production in the kidney and urinary norepinephrine excretion, which were enhanced in the DOCA-salt group, were suppressed by cilnidipine. Cilnidipine also decreased the activity and expression of angiotensin-converting enzyme (ACE) and the aldosterone concentration in the renal homogenate. Although neither cilnidipine nor amlodipine had any effect on the increased blood pressure in the DOCA-salt group, these renal changes were not induced by treatment with amlodipine. In conclusion, cilnidipine inhibited renal dysfunction, sympathetic nerve activity and renal renin-angiotensin-aldosterone system in the DOCA-salt group.

The N-type and L-type calcium channel blocker cilnidipine suppresses renal injury in Dahl rats fed a high-salt diet

The aims of the present study were to compare the effects of cilnidipine [L-type/N-type calcium channel blocker (CCB)] and amlodipine (L-type CCB) alone or in combination with the angiotensin II receptor blocker (ARB), valsartan, on blood pressure (BP), kidney function in Dahl salt-sensitive (DS) rats. DS rats fed a high-salt diet were divided into six groups; control (n = 13), two CCB (cilnidipine or amlodipine) groups at 1 mg/kg/day (n = 10), ARB (valsartan) at 10 mg/kg/day (n = 12), cilnidipine + valsartan (CV, n = 12), and amlodipine + valsartan (AV, n = 12). BPs were lower in the combination therapy groups than in those given either drug alone, but only CV inhibited the increase in urinary albumin excretion (UAE) and lowered the glomerular sclerosis score. In addition, AV elevated plasma renin activity and the angiotensin II concentration, and thus failed to inhibit increases in UAE and to lower glomerular sclerosis score. In conclusion, combination therapy with CCB and ARB decreases BP more effectively than either drug alone. When used in combination with valsartan, cilnidipine is more effective than amlodipine for preventing kidney injury.

Antiproteinuric effect of cilnidipine in hypertensive Japanese treated with renin-angiotensin-system inhibitors - a multicenter, open, randomized trial using 24-hour urine collection

Sustained proteinuria is an important risk factor for not only renal but also cardiovascular morbidity and mortality. Although inhibitors of the renin-angiotensin system (RAS) have been shown to reduce proteinuria. Monotherapy with those drugs is often insufficient for optimal blood pressure (BP)-lowering and therefore, combined therapy is needed. Recent reports suggested that cilnidipine, a dual L-/N-type calcium channel blocker, has renoprotective effect by dilating both efferent and afferent arterioles. In this study, a multicenter, open, randomized trial was designed to compare the antiproteinuric effect between cilnidipine and amlodipine when coupled with RAS inhibitors in hypertensive patients with significant proteinuria. Proteinuria was evaluated by 24-h home urine collection for all patients. A total of 35 proteinuric (>0.1 g/day) patients with uncontrolled BP (>135/85 mmHg) were randomized to receive either cilnidipine (n = 18) or amlodipine (n = 17) after a 6-month treatment with RAS inhibitors and were followed for 48 weeks. At baseline, the cilnidipine group was older and had lower body mass index (BMI) compared to the amlodipine group. After 32 weeks of treatment, diastolic blood pressure (DBP) was slightly, but significantly reduced, in the cilnidipine group, although systolic blood pressure (SBP) and mean BP did not differ. The urinary protein did not differ at baseline (cilnidipine group 0.48 g/day, amlodipine group 0.52 g/day); however, it significantly decreased in the cilnidipine group (0.22 g/day) compared to the amlodipine group (0.50 g/day) after 48 weeks of treatment. Our findings suggest that cilnidipine is superior to amlodipine in preventing the progression of proteinuria in hypertensive patients even undergoing treatment with RAS inhibitors.

Effect of cilnidipine on normal to marginally elevated urine albumin-creatinine ratio in asymptomatic non-diabetic hypertensive patients: an exponential decay curve analysis

BACKGROUND

High-normal urinary albumin excretion has been reported to have clinical significance with respect to progression of proteinuria and hypertension.

OBJECTIVE

We analysed the effect of cilnidipine (10 mg/day) on morning systolic blood pressure (SBP) and urine albumin-creatinine ratio (UACR) in 16 non-diabetic hypertensive patients with a normal to marginally elevated UACR (mean +/- SD 29.4 +/- 21.7; range 7.5-72.9 mg/g creatinine).

METHODS

Sequential home BP and UACR data were fitted to a simple exponential function as follows: where y is SBP (mmHg) or UACR (mg/g creatinine); alpha is the extent of the SBP (mmHg)- or UACR (mg/g creatinine)-lowering effect; beta (days) is the time-constant for SBP or UACR decrease; t is the number of days after the start of cilnidipine administration; and gamma is the finally stabilized SBP (mmHg) or UACR (mg/g creatinine).

RESULTS

Mean +/- SD morning SBP and UACR decreased by 20.4 +/- 11.4 mmHg and 15.2 +/- 13.1 mg/g creatinine, respectively, as determined by coefficient alpha. The mean +/- SD time-constant for UACR decrease was significantly longer than that for BP decrease (43.5 +/- 22.9 vs 15.4 +/- 7.1 days). UACR reduction correlated with pre-treatment UACR values (correlation coefficient [R] = 0.88, p < 0.01) but not with BP decrease.

CONCLUSIONS

The present study demonstrated that cilnidipine reduced UACR in hypertensive patients with normal to marginally elevated UACR independent of its BP-lowering effect.

Cilnidipine suppresses podocyte injury and proteinuria in metabolic syndrome rats: possible involvement of N-type calcium channel in podocyte

OBJECTIVES

Clinical studies have indicated the beneficial effect of an L/N-type calcium channel blocker (CCB), cilnidipine, on the progression of proteinuria in hypertensive patients compared with an L-type CCB, amlodipine. In the present study, we examined the effects of cilnidipine and amlodipine on the renal injury in spontaneously hypertensive rat/ND mcr-cp (SHR/ND) and their underlying mechanism.

METHODS AND RESULTS

SHR/ND were treated with vehicle (nU10), cilnidipine [33 mg/kg per day, orally (p.o.); nU11] or amlodipine (20 mg/kg per day, p.o.; nU9) for 20 weeks. SHR/ND developed proteinuria in an age-dependent manner. Cilnidipine suppressed the proteinuria greater than amlodipine did. The immunohistochemical analysis showed that N-type calcium channel and Wilm's tumor factor, a marker of podocyte, were co-expressed. SHR/ND had significantly greater desmin staining, an indicator of podocyte injury, with lower podocin and nephrin expression in the glomeruli than Wistar-Kyoto rat or SHR. Cilnidipine significantly prevented the increase in desmin staining and restored the glomerular podocin and nephrin expression compared with amlodipine. Cilnidipine also prevented the increase in renal angiotensin II content, the expression and membrane translocation of NADPH oxidase subunits and dihydroethidium staining in SHR/ND. In contrast, amlodipine failed to change these renal parameters.

CONCLUSION

These data suggest that cilnidipine suppressed the development of proteinuria greater than amlodipine possibly through inhibiting N-type calcium channel-dependent podocyte injury in SHR/ND.

Antiproteinuric Effect of an N-Type Calcium Channel Blocker, Cilnidipine

The objective of the present study was to determine anti-proteinuric effect of an N-type calcium channel blocker-cilnidipine. Subjects were 43 essential or renal hypertensive subjects who had been taking calcium channel blockers other than cilnidipine for at least 6 months. All patients had proteinuria greater than 0.2 g/day in spite of fair blood pressure control (<150/90 mmHg). Calcium channel blockers in 25 patients (62+/-3 years) were switched to cilnidipine (cilnidipine group), whereas other 18 patients (58+/-3 years) continued to take originally prescribed calcium channel blockers (control group). The 24-hr urine collections were done at baseline and after 6 months of the follow-up period. Baseline characteristics including age, blood pressure levels, body mass index and creatinine clearance were similar between cilnidipine and control groups. Urinary protein excretion also was comparable between cilnidipine (0.61+/-0.10 g/day) and control (0.86+/-0.17 g/day) groups. Urinary protein significantly decreased after 6 months in cilnidipine group (- 0.21+/- 0.11 g/day, - 36%, p< 0.01), whereas it did not change in control group (+ 0.01+/- 0.15 g/day, 0.4%, ns). There were no significant changes in blood pressure, serum creatinine, creatinine clearance, estimated protein intake, and urinary salt excretion during the follow-up period in either group. The reduction of urinary protein by cilnidipine was evident in essential hypertensives (- 54+/-9%, n=18, p<0.01) but not in renal hypertensives (+10+/-35%, n=7, ns). Results suggest that cilnidipine has an anti-proteinuric effect especially in patients with essential hypertension.

Comparison of renal and vascular protective effects between telmisartan and amlodipine in hypertensive patients with chronic kidney disease with mild renal insufficiency

The present study was conducted to compare the renal and vascular protective effects of telmisartan and amlodipine in untreated hypertensive chronic kidney disease (CKD) patients with moderate renal insufficiency. Thirty hypertensive CKD patients were randomly assigned to receive telmisartan 40 mg (n = 15) or amlodipine 5 mg (n = 15) once daily for 12 months. Changes in blood pressure, serum creatinine, 24-h creatinine clearance (Ccr), proteinuria, brachial-ankle pulse wave velocity (baPWV), intima-media thickness (IMT), plasma interleukin-6 (IL-6), plasma matrix metalloproteinase (MMP)-9 and lipid profiles were monitored in all patients. Before treatment, there were no significant differences in these parameters between the telmisartan and amlodipine groups. Over the 12 month observation period, blood pressure decreased equally in both groups. However, serum creatinine, proteinuria, baPWV, IMT, plasma levels of IL-6 and MMP-9 and total cholesterol decreased and 24-h Ccr increased more strikingly in the telmisartan group than the amlodipine group. These data suggest that telmisartan is more effective than amlodipine for protecting renovascular functions, and potentially for ameliorating atherosclerosis, in hypertensive CKD patients with moderate renal insufficiency.

Renal and vascular protective effects of cilnidipine in patients with essential hypertension

OBJECTIVES

Cilnidipine is a calcium channel blocker that blocks both L and N-type calcium channels. L/N-type calcium channel blockers exhibit sympatholytic action and a renal protective effect via dilation of afferent and efferent arterioles of the renal glomerulus, and afford more potent protection against hypertension-related organ damage than L-type calcium channel blockers. Few studies, however, have directly compared the organ protective effects of L-type calcium channel blocker monotherapy and L/N-type calcium channel blocker monotherapy. This study compares the effects on renal and vascular endothelial functions and arterial stiffness of monotherapy regimens of amlodipine, an L-type calcium antagonist, and cilnidipine, in patients with essential hypertension.

METHODS

Fifty patients with untreated essential hypertension were randomized to receive 5 mg of amlodipine (n = 25) or 10 mg of cilnidipine (n = 25) once daily in the morning for 24 weeks. The patients were evaluated before and after the therapy to assess changes in renal function, flow-mediated vasodilation (a parameter of vascular endothelial function), and brachial-ankle pulse wave velocity (a parameter of arterial stiffness).

RESULTS

Before treatment, the above parameters showed no significant differences between groups. After treatment, urinary albumin excretion was decreased significantly in the cilnidipine group compared with the amlodipine group, and the decrease of brachial-ankle pulse wave velocity was significantly larger in the cilnidipine group than in the amlodipine group.

CONCLUSIONS

These results suggest that cilnidipine is more effective than amlodipine at improving renal function and arterial stiffness in patients with essential hypertension.

Improvement of blood pressure control in hypertensive patients with renal diseases

For hypertensive patients with renal diseases (RD), strict blood pressure (BP) control has been recommended in recent hypertension guidelines, such as JNC VI, JNC 7, WHO/ISH 1999 and ESH-ESC 2003. We assessed the current status of BP control and the changes of BP control before and after the publication of these guidelines in 489 hypertensive patients with or without RD (age, 19-89 years, mean 59+/-13 years) who visited the hypertension and kidney outpatient clinic at Kyushu University Hospital. The clinical characteristics of RD and non-RD patients were assessed (RD patients: age, 20-89 years, mean 60+/-13 years, n=311; non-RD patients: age, 19-86 years, mean 58+/-13 years, n=178). In addition, we compared the BP control status in 2003 to that in 1996. In 2003, the BP in RD patients was 134+/-16/78+/-10 mmHg and that in non-RD patients was 138+/-12/83+/-9 mmHg. When strict BP control was defined as <130/80 mmHg, the frequency of strict BP control in RD patients was 28.9% in 2003. In addition, the BP levels of RD patients in 2003 were significantly lower than those in 1996 (134+/-16/78+/-10 mmHg vs. 141+/-17/85+/-10 mmHg, p<0.05 for both systolic blood pressure [SBP] and diastolic blood pressure [DBP]), and the frequency of strict BP control in RD patients was higher in 2003 than in 1996 (28.9% vs. 11.8%, p<0.01). The BP levels of non-RD patients in 2003 tended to be lower than those in 1996 (138+/-12/83+/-9 mmHg vs. 141+/-13/85+/-9 mmHg, n.s.). In 2003, angiotensin II receptor blockers (ARBs) were more frequently prescribed to RD patients than to non-RD patients. Furthermore, the use of ARBs was markedly increased in 2003 compared with 1996. In conclusion, in our outpatient clinic, BP levels in hypertensive patients with RD have improved in recent years, and were lower than those in hypertensive patients without RD, which may in part reflect the physicians' awareness of the importance of strict BP control in RD patients, as suggested by several recent hypertension guidelines.

Renoprotective effect of N-type Ca channel blockade in diabetic nephropathy

OBJECTIVE

This study aimed to investigate the renoprotective effect on diabetic nephropathy of a novel class of Ca(2+) channel blocker, cilnidipine, that inhibits both L-type and N-type Ca(2+) channels; a conventional L-type Ca(2+) channel blocker was substituted with cilnidipine in type 2 diabetic patients with albuminuria.

METHODS

Urinary albumin index (UAI), serum creatinine, and blood pressure were measured in 38 outpatients with type 2 diabetes receiving amlodipine, an L-type Ca(2+) channel blocker, in addition to an angiotensin I converting enzyme inhibitor and/or an angiotensin type 1 receptor blocker. Amlodipine was then substituted with cilnidipine, and the same parameters were measured after 3 months.

RESULTS

Although blood pressure was not significantly changed after substitution with cilnidipine, log-transformed UAI was significantly decreased (P=.004) with a mean reduction of 28% [95% confidence interval (CI)=11-42]. Serum creatinine was significantly (P=.04) increased (from 0.82+/-0.22 to 0.86+/-0.23 mg/dl). When the subjects were divided into two groups according to the change in serum creatinine, UAI change was significant only in those with an increase in serum creatinine, who exhibited a mean reduction of UAI of 39% (95% CI=16-56, P=.005), but not in those without an increase in serum creatinine, whose mean reduction of UAI was 18% (95% CI=-12 to 40, P=.2).

CONCLUSIONS

In patients with diabetic nephropathy, blocking N-type Ca(2+) channels with a new class of Ca(2+) channel blocker resulted in a significant reduction in albuminuria, suggesting a renoprotective effect of N-type Ca(2+) channel blockade, even when combined with renin-angiotensin inhibition.

Comparison of the effects of cilnidipine and amlodipine on ambulatory blood pressure

Cilnidipine is a novel and unique 1,4-dydropyridine derivative calcium antagonist that exerts potent inhibitory actions not only on L-type but also on N-type voltage-dependent calcium channels. Blockade of the neural N-type calcium channel inhibits the secretion of norepinephrine from peripheral neural terminals and depresses sympathetic nervous system activity. The purpose of this study was to assess the effect of cilnidipine and amlodipine on ambulatory blood pressure (BP) levels. We performed 24-h ambulatory BP monitoring before and after once-daily use of cilnidipine (n=55) and amlodipine (n=55) in 110 hypertensive patients. Both drugs significantly reduced clinic and 24-h systolic BP (SBP) and diastolic BP (DBP) (p < 0.005). However, the reductions of 24-h (-1.19+/-6.78 vs. 1.55+/-6.13 bpm, p=0.03), daytime (-1.58+/-6.72 vs. 1.68+/-7.34 bpm, p=0.02) and nighttime (-1.19+/-5.72 vs. 1.89+/-6.56 bpm, p=0.01) pulse rate (PR) were significantly greater in the cilnidipine group than the amlodipine group. There was no correlation between the degree of daytime SBP change and that of daytime PR change after amlodipine treatment (r=-0.08, n.s.), but there was a significant negative correlation between the degree of daytime SBP change and that of day-time PR change after cilnidipine treatment (r=-0.27, p<0.05). N-type calcium channel blockade by cilnidipine may not cause reflex tachycardia, and may be useful for hypertensive treatment.

New Generation Calcium Channel Blockers in Hypertensive Treatment

During a couple of decades, a number of antihypertensive drugs have been developed, and the choice of hypertension treatment has been expanded. Among antihypertensive drugs, calcium channel blockers, which inhibit L-type voltage-gated calcium channels, are potent vasodilators, and have been used as a first- or second-line drug. Dihydropyridine-class calcium channel blockers are categorized into three generations according to the length of activity, and long-acting calcium channel blockers cause less activation of sympathetic nervous system, and are reported to offer beneficial action compared with short-action agents. Furthermore, novel types of calcium channel blockers have been developed that possess the blocking action on other calcium channel subtypes (T- and N-type), and exert agent-specific action apart from their class effects, such as the effects on heart rate and renin/aldosterone release. These additional benefits conferred by T/N-type calcium channel blockade are anticipated to provide organ protective actions in the treatment of hypertension, in addition to the blood pressure-lowering effect of L-type calcium channel blockade. In conclusion, novel calcium channel blockers with sustained activity and T/N-type calcium channel blocking action could provide more beneficial effects than classical blockers, and may expand the clinical utility of these agents.