L-/T-type Ca channel blockers for kidney protection: ready for sophisticated use of Ca channel blockers

Serum symmetric dimethylarginine concentrations in enalapril- or telmisartan-treated dogs with proteinuric chronic kidney disease

Introduction

Renin-angiotensin-aldosterone system inhibition (RAASi) reduces intraglomerular pressure and is a standard therapy for dogs with proteinuric chronic kidney disease (CKD). RAASi can acutely decrease glomerular filtration rate (GFR); however, its effects on the marker of GFR serum symmetric dimethylarginine (SDMA) concentration in dogs have not been specifically evaluated. The objective of this study was to evaluate changes, relative to pretreatment values, in serum SDMA concentrations in dogs with proteinuric CKD receiving RAASi therapy.

Methods

This retrospective study used banked samples from 29 dogs with proteinuric CKD treated with enalapril (0.5 mg/kg PO q12h; n = 16) or telmisartan (1 mg/kg PO q24h; n = 13) alone (n = 22) or in combination with amlodipine if severely hypertensive (n = 7). Serum SDMA, creatinine, and urea nitrogen (SUN) concentrations were measured before and 7 and 30 days after starting RAASi. Percentage and absolute changes in these biomarkers were calculated for each dog and time point. A linear mixed model was used to test whether changes significantly differed from zero (α < 0.05).

Results

Overall, mean ± SEM Day 7 and 30 percentage change in SDMA were  - 4.8 ± 3.6% and  - 3.2 ± 3.4%, respectively; in creatinine were 7.4 ± 3.3% and 3.0 ± 3.1%, respectively; and in SUN were 22.1 ± 6.8% and 16.7 ± 6.2%, respectively. Mean changes varied according to whether all dogs, those on RAASi alone, or those co-treated with amlodipine were evaluated. In dogs receiving RAASi alone, at day 7, there were significant mean percentual increases in creatinine (9%; p = 0.023) and SUN (23%; p = 0.005), but SDMA was unchanged. In dogs co-treated with amlodipine, a significant absolute decrease in mean SDMA (-2.29 μg/dL; p = 0.026) occurred at days 7 and 30, while mean creatinine was unchanged and mean SUN increased.

Discussion

Proteinuric dogs receiving RAASi had low-magnitude changes in serum SDMA and creatinine, and moderate-magnitude changes in SUN concentrations. The direction of change in SDMA did not consistently match that of creatinine and SUN.

Therapeutic Usefulness of a Novel Calcium Channel Blocker Azelnidipine in the Treatment of Hypertension: A Narrative Review

The prevalence of hypertension and comorbidities such as metabolic syndrome, diabetes mellitus, and chronic kidney disease in India is alarmingly high. Amlodipine, an older-generation calcium channel blocker (CCB), is currently the gold standard for hypertension management in India. However, it has several disadvantages, including reflex tachycardia and pedal edema. Therefore, an effective antihypertensive agent that does not cause these adverse effects and provides end-organ protection is required for the holistic management of hypertension in the country. Azelnidipine is a new-generation CCB that has recently been approved for the treatment of hypertension in India. This review provides an overview of the utility of azelnidipine for hypertension control, including comparisons with traditional CCBs such as amlodipine. It discusses the key antihypertensive effects of azelnidipine as well as its advantages in the prevention of tachycardia and associated complications. In addition, this review highlights the extensive cardio- and renoprotective activities of azelnidipine, including its effects on systolic and diastolic function and urinary albumin excretion. Overall, this substantial body of evidence supports the use of azelnidipine for the treatment of hypertension, especially in India. It suggests that the adoption of azelnidipine as the new gold standard CCB could help India battle its hypertension epidemic.

Pharmacokinetics, Safety and Tolerability of Tylerdipine Hydrochloride, a Novel Dihydropyridine Dual L/T-type Calcium Channel Blocker, after Single and Multiple Oral Doses in Healthy Chinese Subjects

BACKGROUND AND OBJECTIVE

Tylerdipine hydrochloride (KBP-5660) is a novel L/T-type dual calcium channel blocker developed for the treatment of hypertension. We aimed to study the pharmacokinetics, safety and tolerability of tylerdipine in healthy Chinese subjects.

METHODS

Two double-blind, randomized, dose-escalation studies were conducted that included a total of 88 healthy subjects: (1) a single-ascending dose (SAD) study; and (2) a multiple-ascending dose (MAD) study. In the SAD study, 64 subjects were randomly assigned to receive a single dose of 0.5, 2.5, 5, 10, 15, 20, 25, or 30 mg of tylerdipine or placebo. In the MAD study, 24 subjects were randomly assigned to receive 10 or 20 mg of tylerdipine or placebo once daily for 9 days. Blood samples were collected at the designated time points for pharmacokinetic analyses. Safety assessments were conducted throughout the study.

RESULTS

Following a single oral dose of tylerdipine of 5-30 mg, the mean maximum plasma concentration (C_max) increased from 0.9993 to 10.11 ng/ml; mean area under the plasma-concentration curve (AUC) from time zero to 72 h increased from 4.332 to 73.95 h·ng/ml. AUC increased in a greater than dose-proportional manner, whereas C_max exhibited a rough but non-typical dose-proportionality increase. In the MAD study, steady-state conditions were achieved after 1 week of daily dosing in both dose groups. Accumulation of tylerdipine was low, with accumulation ratios (R_AUC) of less than 1.65. All adverse events were assessed as mild or moderate.

CONCLUSION

Tylerdipine hydrochloride was safe and well tolerated. The exposure (AUC) of tylerdipine over the dose range of 5-30 mg increased in a greater than dose-proportional manner, while C_max exhibited a rough but non-typical dose proportionality increase. A slight accumulation of tylerdipine was observed following multiple dosing.

STUDY REGISTRATIONS

CTR20140862 and CTR20150660.

Effects of Calcium-Channel Blocker Benidipine-Based Combination Therapy on Cardiac Events - Subanalysis of the COPE Trial

BACKGROUND

The Combination Therapy of Hypertension to Prevent Cardiovascular Events (COPE) trial was conducted to compare the effects of regimens combining the dihydropyridine calcium-channel blocker benidipine with each of 3 secondary agent types (an angiotensin-receptor blocker (ARB), a β-blocker and a thiazide) in Japanese hypertensive outpatients who did not achieve target blood pressure (<140/90 mmHg) with benidipine 4 mg/day alone. The analysis included 3,293 patients (ARB, 1,110; β-blocker, 1,089; thiazide, 1,094) with a median follow-up of 3.61 years. The main results of the COPE trial demonstrated that the incidences of hard cardiovascular composite endpoints and fatal or non-fatal strokes were significantly higher in the benidipine/β-blocker group than in the benidipine/thiazide group.

METHODS AND RESULTS

We further evaluated the treatment effects on different cardiac events among the 3 benidipine-based regimens.We observed a total of 50 cardiac events, 4.2 per 1000 person-years. The incidences of total cardiac events and each cardiac event were similarly low among the 3 treatment groups. Unadjusted and multi-adjusted hazard ratios for total cardiac events showed no significant difference among the 3 treatment groups.

CONCLUSIONS

This subanalysis of the COPE trial demonstrated that blood pressure-lowering regimens combining benidipine with an ARB, β-blocker or thiazide diuretic were similarly effective for the prevention of cardiac events in Japanese hypertensive outpatients.

Effects of a benidipine-based combination therapy on the risk of stroke according to stroke subtype: the COPE trial

The Combination Therapy of Hypertension to Prevent Cardiovascular Events (COPE) trial compared the dihydropyridine T/L-type calcium channel blocker benidipine-based therapies when combined with an angiotensin receptor blocker (ARB), a β-blocker (BB) or a thiazide diuretic (TD). The results suggested that benidipine combined with a BB appeared to be less beneficial in reducing the risk of stroke compared with the benidipine-TD combination (hazard ratio (HR): 2.31, P=0.0109). We further evaluated the treatment effects on different stroke subtypes among the three benidipine-based regimens. The COPE trial was an investigator-initiated, multicenter study with PROBE design. Patients with atrial fibrillation or flutter were excluded from the study. All stroke events were subclassified with the Trial of Org 10,172 in Acute Stroke Treatment (TOAST) criteria. The total incidence of stroke was 4.7, hemorrhagic stroke was 1.6 and ischemic stroke was 2.5 per 1000 person-years. The incidence of lacunar stroke was 1.1, large-artery stroke was 0.6, cardioembolic stroke was 0.3, unknown ischemic type was 0.6 and transient ischemic attack was 0.6 per 1000 person-years. Although few differences in stroke subtypes were observed among the three treatment groups, multi-adjusted HRs for the incidence rates of all types of stroke, hemorrhagic stroke and ischemic stroke were significantly higher with the benidipine-BB regimen than with the benidipine-TD regimen. The incidence of both hemorrhagic and ischemic stroke in the benidipine-ARB regimen was not different compared with the other two treatment regimens. This prespecified sub-analysis suggested that a blood pressure-lowering therapy with a benidipine-TD regimen might be beneficial for hypertensive patients to prevent both hemorrhagic and ischemic stroke.