The role of existing and newer calcium channel blockers in the treatment of hypertension

Traditional Therapeutics and Potential Epidrugs for CVD: Why Not Both?

Cardiovascular disease (CVD) is the leading cause of death worldwide. In addition to the high mortality rate, people suffering from CVD often endure difficulties with physical activities and productivity that significantly affect their quality of life. The high prevalence of debilitating risk factors such as obesity, type 2 diabetes mellitus, smoking, hypertension, and hyperlipidemia only predicts a bleak future. Current traditional CVD interventions offer temporary respite; however, they compound the severe economic strain of health-related expenditures. Furthermore, these therapeutics can be prescribed indefinitely. Recent advances in the field of epigenetics have generated new treatment options by confronting CVD at an epigenetic level. This involves modulating gene expression by altering the organization of our genome rather than altering the DNA sequence itself. Epigenetic changes are heritable, reversible, and influenced by environmental factors such as medications. As CVD is physiologically and pathologically diverse in nature, epigenetic interventions can offer a ray of hope to replace or be combined with traditional therapeutics to provide the prospect of addressing more than just the symptoms of CVD. This review discusses various risk factors contributing to CVD, perspectives of current traditional medications in practice, and a focus on potential epigenetic therapeutics to be used as alternatives.

An Update on Drug-Nutrient Interactions and Dental Decay in Older Adults

In recent decades, the global demographic landscape has undergone a discernible shift that has been characterised by a progressive increase in the proportion of elderly individuals, indicative of an enduring global inclination toward extended lifespans. The aging process, accompanied by physiological changes and dietary patterns, contributes to detrimental deviations in micronutrient consumption. This vulnerable aging population faces heightened risks, including dental caries, due to structural and functional modifications resulting from insufficient nutritional sustenance. Factors such as physiological changes, inadequate nutrition, and the prevalence of multiple chronic pathologies leading to polypharmacy contribute to the challenge of maintaining an optimal nutritional status. This scenario increases the likelihood of drug interactions, both between medications and with nutrients and the microbiome, triggering complications such as dental decay and other pathologies. Since the drug industry is evolving and new types of food, supplements, and nutrients are being designed, there is a need for further research on the mechanisms by which drugs interfere with certain nutrients that affect homeostasis, exemplified by the prevalence of caries in the mouths of older adults. Infectious diseases, among them dental caries, exert serious impacts on the health and overall quality of life of the elderly demographic. This comprehensive review endeavours to elucidate the intricate interplay among drugs, nutrients, the microbiome, and the oral cavity environment, with the overarching objective of mitigating the potential hazards posed to both the general health and dental well-being of older adults. By scrutinising and optimising these multifaceted interactions, this examination aims to proactively minimise the susceptibility of the elderly population to a spectrum of health-related issues and the consequences associated with dental decay.

Differential Preincubation Effects of Nicardipine on OATP1B1- and OATP1B3-Mediated Transport in the Presence and Absence of Protein: Implications in Assessing OATP1B1- and OATP1B3-Mediated Drug-Drug Interactions

Impaired transport activity of hepatic OATP1B1 and OATP1B3 due to drug-drug interactions (DDIs) often leads to increased systemic exposure to substrate drugs (e.g., lipid-lowering statins). Since dyslipidemia and hypertension frequently coexist, statins are often concurrently used with antihypertensives, including calcium channel blockers (CCBs). OATP1B1/1B3-related DDIs in humans have been reported for several CCBs. To date, the OATP1B1/1B3-mediated DDI potential of CCB nicardipine has not been assessed. The current study was designed to assess the OATP1B1- and OATP1B3-mediated DDI potential of nicardipine using the R-value model, following the US-FDA guidance. IC50 values of nicardipine against OATP1B1 and OATP1B3 were determined in transporter-overexpressing human embryonic kidney 293 cells using [3H]-estradiol 17β-D-glucuronide and [3H]-cholecystokinin-8 as substrates, respectively, with or without nicardipine-preincubation in protein-free Hanks' Balanced Salt Solution (HBSS) or in fetal bovine serum (FBS)-containing culture medium. Preincubation with nicardipine for 30 min in protein-free HBSS buffer produced lower IC50 and higher R-values for both OATP1B1 and OATP1B3 compared to in FBS-containing medium, yielding IC50 values of 0.98 and 1.63 µM and R-values of 1.4 and 1.3 for OATP1B1 and OATP1B3, respectively. The R-values were higher than the US-FDA cut-off value of 1.1, supporting that nicardipine has the potential to cause OATP1B1/3-mediated DDIs. Current studies provide insight into the consideration of optimal preincubation conditions when assessing the OATP1B1/3-mediated DDIs in vitro.

Impaired CaV1.2 inactivation reduces the efficacy of calcium channel blockers in the treatment of LQT8

Mutations in the CaV1.2 L-type calcium channel can cause a profound form of long-QT syndrome known as long-QT type 8 (LQT8), which results in cardiac arrhythmias that are often fatal in early childhood. A growing number of such pathogenic mutations in CaV1.2 have been identified, increasing the need for targeted therapies. As many of these mutations reduce channel inactivation; resulting in excess Ca2+ entry during the action potential, calcium channel blockers (CCBs) would seem to represent a promising treatment option. Yet CCBs have been unsuccessful in the treatment of LQT8. Here, we demonstrate that this lack of efficacy likely stems from the impact of the mutations on CaV1.2 channel inactivation. As CCBs are known to preferentially bind to the inactivated state of the channel, mutation-dependent deficits in inactivation result in a decrease in use-dependent block of the mutant channel. Further, application of the CCB verapamil to induced pluripotent stem cell (iPSC) derived cardiomyocytes from an LQT8 patient demonstrates that this loss of use-dependent block translates to a lack of efficacy in correcting the LQT phenotype. As a growing number of channelopathic mutations demonstrate effects on channel inactivation, reliance on state-dependent blockers may leave a growing population of patients without a viable treatment option. This biophysical understanding of the interplay between inactivation deficits and state-dependent block may provide a new avenue to guide the development of improved therapies.

The Role of Verapamil Toxicity in the Vicious Cycle of Bradycardia, Renal Failure, Atrioventricular Nodal Blockade, Shock, and Hyperkalemia (BRASH) Syndrome: A Case Report

BRASH is an acronym describing the vicious cycle seen in patients taking atrioventricular (AV) nodal blockers who tend to present with bradycardia, renal failure, atrioventricular nodal blockade, shock, and hyperkalemia. Herein, we report the case of an 87-year-old hypertensive patient on verapamil who presented with complaints of fever and shortness of breath. She was found to have bradycardia, hyperkalemia, renal impairment, and borderline hypotension. Differentiating this case from previous case reports on BRASH syndrome, this patient was found to simultaneously have toxic levels of serum verapamil.

Novel Polymeric Nanomaterial Based on Poly(Hydroxyethyl Methacrylate-Methacryloylamidophenylalanine) for Hypertension Treatment: Properties and Drug Release Characteristics

In this study, a novel polymeric nanomaterial was synthesized and characterized, and it its potential usability in hypertension treatment was demonstrated. For these purposes, a poly(hydroxyethyl methacrylate-methacryloylamidophenylalanine)-based polymeric nanomaterial (p(HEMPA)) was synthesized using a mini-emulsion polymerization technique. The nanomaterials were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and zeta size analysis. The synthesized p(HEMPA) nanomaterial had a diameter of about 113 nm. Amlodipine-binding studies were optimized by changing the reaction conditions. Under optimum conditions, amlodipine's maximum adsorption value (Qmax) of the p(HEMPA) nanopolymer was found to be 145.8 mg/g. In vitro controlled drug release rates of amlodipine, bound to the nanopolymer at the optimum conditions, were studied with the dialysis method in a simulated gastrointestinal system with pH values of 1.2, 6.8 and 7.4. It was found that 99.5% of amlodipine loaded on the nanomaterial was released at pH 7.4 and 72 h. Even after 72 h, no difference was observed in the release of AML. It can be said that the synthesized nanomaterial is suitable for oral amlodipine release. In conclusion, the synthesized nanomaterial was studied for the first time in the literature as a drug delivery system for use in the treatment of hypertension. In addition, AML-p(HEMPA) nanomaterials may enable less frequent drug uptake, have higher bioavailability, and allow for prolonged release with minimal side effects.

Effect of Calcium Channel Blockers versus Diuretics for Hypertension

Background

Although calcium channel blockers (CCBs) are recognized as clinical first-line agents for the treatment of hypertension, their use in combination with diuretics in cardiovascular disease caused by hypertension remains controversial.

Methods

We searched the three major databases of the Cochrane Library, EMBASE, and PubMed for the terms “calcium channel blockers,” “thiazide diuretics,” “loop diuretics,” and “hypertension,” “randomized controlled trials” and “meta-analysis trials.” These terms were searched from January 1991 to October 2021.

Results

For the primary outcome, in 5 studies including 35,057 patients, there was no statistically significant difference in all-cause mortality with calcium channel blockers compared with diuretics (RR = 0.98, 95% CI 0.92–1.04, I² = 0). In four studies including 33,643 patients with major cardiovascular events, there was no statistically significant difference in major cardiovascular events with calcium channel blockers compared with diuretics (RR = 1.00, 95% CI 1.04–1.09, I² = 0).

Conclusion

There is no statistically significant difference between calcium channel blockers and diuretics in terms of cardiovascular clinical prognosis in hypertensive patients, but there are positive implications for clinical guidance, which need to be fully validated in new large randomized controlled trials.

A Novel High Content Angiogenesis Assay Reveals That Lacidipine, L-Type Calcium Channel Blocker, Induces In Vitro Vascular Lumen Expansion

Angiogenesis is a critical cellular process toward establishing a functional circulatory system capable of delivering oxygen and nutrients to the tissue in demand. In vitro angiogenesis assays represent an important tool for elucidating the biology of blood vessel formation and for drug discovery applications. Herein, we developed a novel, high content 2D angiogenesis assay that captures endothelial morphogenesis’s cellular processes, including lumen formation. In this assay, endothelial cells form luminized vascular-like structures in 48 h. The assay was validated for its specificity and performance. Using the optimized assay, we conducted a phenotypic screen of a library containing 150 FDA-approved cardiovascular drugs to identify modulators of lumen formation. The screening resulted in several L-type calcium channel blockers being able to expand the lumen space compared to controls. Among these blockers, Lacidipine was selected for follow-up studies. We found that the endothelial cells treated with Lacidipine showed enhanced activity of caspase-3 in the luminal space. Pharmacological inhibition of caspase activity abolished the Lacidipine-enhancing effect on lumen formation, suggesting the involvement of apoptosis. Using a Ca²⁺ biosensor, we found that Lacipidine reduces the intracellular Ca²⁺ oscillations amplitude in the endothelial cells at the early stage, whereas Lacidipine blocks these Ca²⁺ oscillations completely at the late stage. The inhibition of MLCK exhibits a phenotype of lumen expansion similar to that of Lacidipine. In conclusion, this study describes a novel high-throughput phenotypic assay to study angiogenesis. Our findings suggest that calcium signalling plays an essential role during lumen morphogenesis. L-type Ca²⁺ channel blockers could be used for more efficient angiogenesis-mediated therapies.

Antiretroviral Treatment and Antihypertensive Therapy

The presence of hypertension among the population with human immunodeficiency virus (HIV) has become a new threat to the health and well-being of people living with this disease, in particular, among those who received antiretroviral therapy. The estimated prevalence of high blood pressure in HIV-infected patients is significantly higher than the rate observed in HIV-uninfected subjects. The approach to the HIV-positive patient requires the assessment of individual cardiovascular risk and its consideration when designing the individualized target. On the other hand, the numerous pharmacological interactions of antiretroviral (ARV) drugs are essential elements to take into account. Serum levels of any kind of antihypertensive drugs may be influenced by the coadministration of protease inhibitors, non-nucleoside reverse transcriptase inhibitor, or other antiretroviral. Similarly, plasma concentrations of antiretroviral drugs can be increased by the concomitant use of calcium channel blockers or diuretics. In this regard, the treatment of high blood pressure in HIV patients should be preferentially based on ACE inhibitors or thiazide/thiazide-like diuretics or their combination.

Artificial neural network model for predicting changes in ion channel conductance based on cardiac action potential shapes generated via simulation

Many studies have revealed changes in specific protein channels due to physiological causes such as mutation and their effects on action potential duration changes. However, no studies have been conducted to predict the type of protein channel abnormalities that occur through an action potential (AP) shape. Therefore, in this study, we aim to predict the ion channel conductance that is altered from various AP shapes using a machine learning algorithm. We perform electrophysiological simulations using a single-cell model to obtain AP shapes based on variations in the ion channel conductance. In the AP simulation, we increase and decrease the conductance of each ion channel at a constant rate, resulting in 1,980 AP shapes and one standard AP shape without any changes in the ion channel conductance. Subsequently, we calculate the AP difference shapes between them and use them as the input of the machine learning model to predict the changed ion channel conductance. In this study, we demonstrate that the changed ion channel conductance can be predicted with high prediction accuracy, as reflected by an F1 score of 0.985, using only AP shapes and simple machine learning.

Antihypertensive Effects of the Vitex cienkowskii (Verbenaceae) Stem-Bark Extract on L-NAME-Induced Hypertensive Rats

Vitex cienkowskii stem-bark is used in Cameroonian traditional medicine to treat cardiovascular diseases including hypertension. In previous studies, the methanol/methylene chloride stem-bark extract of Vitex cienkowskii (MMVC) showed a preventive activity in L-NAME-induced hypertension and improved blood pressure of spontaneously hypertensive rats. The present study investigated the curative effects in L-NAME-induced hypertensive rats (LNHR). Hypertension was induced in rats by oral administration of L-NAME (40 mg/kg/day) for 28 days. The animals were divided into 2 groups: one group of 5 rats receiving distilled water (10 ml/kg) and another 20 rats receiving L-NAME. At the end of 4 weeks of administration of L-NAME, the animals were divided into 4 groups of 5 rats each: one group of hypertensive rats receiving distilled water, another one receiving captopril (25 mg/kg), and two groups of hypertensive rats receiving MMVC at doses of 200 and 400 mg/kg, respectively. Body weight, food, and water intake were measured weekly. At the end of the treatment, blood pressure and heart rate were recorded by invasive method. Whole heart, left ventricle, kidneys, and liver were weighed. The effects of plant extract on lipid profile and oxidative stress markers, as well as markers of hepatic and renal functions were assessed spectrophotometrically according to well described protocols. Results show that L-NAME significantly increases the mean arterial blood pressure (MABP), atherogenic index, lipid profile, and creatinine and transaminase activities of normotensive rats. MMVC significantly reduced the blood pressure in LNHR. Body weight, food and water intake, left ventricular hypertrophy, antioxidant level, renal and hepatic markers, and lipid profile were improved by the treatment with MMVC. The curative effect of MMVC on L-NAME-induced hypertension is probably related to its antihypertensive, hypolipidemic, and antioxidant properties. These results confirmed the use of Vitex cienkowskii for the treatment of hypertension in traditional medicine.

Calcium channel blockers for people with chronic kidney disease requiring dialysis

BACKGROUND

Calcium channel blockers (CCBs) are used to manage hypertension which is highly prevalent among people with chronic kidney disease (CKD). The treatment for hypertension is particularly challenging in people undergoing dialysis.

OBJECTIVES

To assess the benefits and harms of calcium channel blockers in patients with chronic kidney disease requiring dialysis.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies to 27 April 2020 through contact with the Information Specialist using search terms relevant to this review. Studies in the Specialised Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs that compared any type of CCB with other CCB, different doses of the same CCB, other antihypertensives, control or placebo were included. The minimum study duration was 12 weeks.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. Statistical analyses were performed using a random-effects model and results expressed as risk ratio (RR), risk difference (RD) or mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

This review included 13 studies (24 reports) randomising 1459 participants treated with long-term haemodialysis. Nine studies were included in the meta-analysis (622 participants). No studies were performed in children or in those undergoing peritoneal dialysis. Overall, risk of bias was assessed as unclear to high across most domains. Random sequence generation and allocation concealment were at low risk of bias in eight and one studies, respectively. Two studies reported low risk methods for blinding of participants and investigators, and outcome assessment was blinded in 10 studies. Three studies were at low risk of attrition bias, eight studies were at low risk of selective reporting bias, and five studies were at low risk of other potential sources of bias. Overall, the certainty of the evidence was low to very low for all outcomes. No events were reported for cardiovascular death in any of the comparisons. Other side effects were rarely reported and studies were not designed to measure costs. Five studies (451 randomised adults) compared dihydropyridine CCBs to placebo or no treatment. Dihydropyridine CCBs may decrease predialysis systolic (1 study, 39 participants: MD -27.00 mmHg, 95% CI -43.33 to -10.67; low certainty evidence) and diastolic blood pressure level (2 studies, 76 participants; MD -13.56 mmHg, 95% CI -19.65 to -7.48; I² = 0%, low certainty evidence) compared to placebo or no treatment. Dihydropyridine CCBs may make little or no difference to occurrence of intradialytic hypotension (2 studies, 287 participants; RR 0.54, 95% CI 0.25 to 1.15; I² = 0%, low certainty evidence) compared to placebo or no treatment. Other side effects were not reported. Eight studies (1037 randomised adults) compared dihydropyridine CCBs to other antihypertensives. Dihydropyridine CCBs may make little or no difference to predialysis systolic (4 studies, 180 participants: MD 2.44 mmHg, 95% CI -3.74 to 8.62; I² = 0%, low certainty evidence) and diastolic blood pressure (4 studies, 180 participants: MD 1.49 mmHg, 95% CI -2.23 to 5.21; I² = 0%, low certainty evidence) compared to other antihypertensives. There was no evidence of a difference in the occurrence of intradialytic hypotension (1 study, 92 participants: RR 2.88, 95% CI 0.12 to 68.79; very low certainty evidence) between dihydropyridine CCBs to other antihypertensives. Other side effects were not reported. Dihydropyridine CCB may make little or no difference to predialysis systolic (1 study, 40 participants: MD -4 mmHg, 95% CI -11.99 to 3.99; low certainty evidence) and diastolic blood pressure (1 study, 40 participants: MD -3.00 mmHg, 95% CI -7.06 to 1.06; low certainty evidence) compared to non-dihydropyridine CCB. There was no evidence of a difference in other side effects (1 study, 40 participants: RR 0.13, 95% CI 0.01 to 2.36; very low certainty evidence) between dihydropyridine CCB and non-dihydropyridine CCB. Intradialytic hypotension was not reported.

AUTHORS' CONCLUSIONS

The benefits of CCBs over other antihypertensives on predialysis blood pressure levels and intradialytic hypotension among people with CKD who required haemodialysis were uncertain. Effects of CCBs on other side effects and cardiovascular death also remain uncertain. Dihydropyridine CCBs may decrease predialysis systolic and diastolic blood pressure level compared to placebo or no treatment. No studies were identified in children or peritoneal dialysis. Available studies have not been designed to measure the effects on costs. The shortcomings of the studies were that they recruited very few participants, had few events, had very short follow-up periods, some outcomes were not reported, and the reporting of outcomes such as changes in blood pressure was not done uniformly across studies. Well-designed RCTs, conducted in both adults and children with CKD requiring both haemodialysis and peritoneal dialysis, evaluating both dihydropyridine and non-dihydropyridine CCBs against other antihypertensives are required. Future research should be focused on outcomes relevant to patients (including death and cardiovascular disease), blood pressure changes, risk of side effects and healthcare costs to assist decision-making in clinical practice.

Comparison of amlodipine with cilnidipine on antihypertensive efficacy and incidence of pedal edema in mild to moderate hypertensive individuals: A prospective study

To compare amlodipine with cilnidipine on antihypertensive efficacy and incidence of pedal edema in hypertensive individuals. This was a three months prospective, observational study done at the tertiary care center of Karnataka, India. A total number of 60 (n = 60) newly diagnosed hypertensives (≥140/90) of either gender, attending outpatient department of medicine, were included in the study. Out of 60 patients, 30 patients who have been prescribed tablet amlodipine 5–10 mg/day and the other 30 who have been prescribed tablet cilnidipine 10–20 mg/day orally by the consulting physician, depending upon the severity of hypertension were followed every fortnight, screened for the presence of pedal edema and blood pressure control over a period of 3 months. Antihypertensive efficacy between two groups was compared by unpaired t-test and incidence of pedal edema was compared by Fisher's exact test. Of 30 patients in the amlodipine group, 19 patients presented with pedal edema (63.3%) and 2 patients (6.66%) in cilnidipine group presented with pedal edema during the study period. There was a significant difference in the incidence of pedal edema between amlodipine and cilnidipine group (P < 0.05), but no significant difference was found in the antihypertensive efficacy of amlodipine and cilnidipine (P > 0.05). Both amlodipine and cilnidipine have shown equal efficacy in reducing blood pressure in hypertensive individuals. But cilnidipine being N-type and L-type calcium channel blocker, associated with lower incidence of pedal edema compared to only L-type channel blocked by amlodipine.

Effects of lercanidipine versus amlodipine in hypertensive patients with cerebral ischemic stroke

OBJECTIVE

The aim of this study was to compare the efficacy and safety of lercanidipine and amlodipine in the treatment of hypertensive patients with acute cerebral ischemic stroke.

RESEARCH DESIGN AND METHODS

An open label, controlled, randomized, parallel-group study was conducted on 104 hypertensive patients (blood pressure [BP] >130/80 mmHg) diagnosed with ischemic stroke. Enrolled subjects were randomly assigned to a 4 week treatment with lercanidipine 20 mg/day or amlodipine 10 mg/day. The treatment was administered during the acute phase of the stroke, either immediately after the diagnosis or during an observation period of maximum 6 days.

RESULTS

Both lercanidipine and amlodipine were able to significantly reduce mean clinical systolic BP (SBP)/diastolic BP (DBP), mean 24 h ambulatory BP and day-time and night-time BP. In particular, mean clinical SBP/DBP was reduced from 168.9 ± 21.6/96.2 ± 13.6 mmHg to 147.1 ± 22.0/87.1 ± 14.0 mmHg in the lercanidipine group (p < 0.001 for SBP and p < 0.01 for DBP) and from 167.1 ± 19.9/97.8 ± 14.5 mmHg to 143.3 ± 21.9/82.8 ± 14.1 mmHg in the amlodipine-treated group (p < 0.001 for both SBP and DBP). No statistical difference was observed between the two treatments in the reduction of clinical BP. The response and normalization rates registered in the two groups of patients were also similar, with no significant difference between the two drugs. In addition, both treatments reported comparable results in terms of early morning BP surge reduction and BP stabilization, measured through trough-peak ratio and smoothness index. However lercanidipine showed a better tolerability profile than amlodipine, with fewer adverse events and a lower percentage of patients suffering from side effects.

CONCLUSIONS

Lercanidipine is as effective as amlodipine in the reduction and stabilization of BP in hypertensive patients after a stroke, and presents some advantages in terms of safety. Larger studies are necessary to further evaluate these preliminary findings.

Diltiazem reduces mortality and breakdown of ATP in red blood cell induced by isoproterenol in a freely moving rat model in vivo

The benefit of calcium channel blockers for cardiovascular prevention against heart attack and stroke has not been firmly supported. We investigated the possible cardiovascular protective effect of diltiazem (DTZ) against injury induced by isoproterenol using a freely moving rat model in vivo. Sprague Dawley rats were injected subcutaneously (sc) with either 5 or 10 mg/kg of DTZ, or saline as control, twice daily for five doses. One hour after the last injection, a single dose of isoproterenol (30 mg/kg) was injected sc to each rat. Blood samples were collected serially for 6 h for measurement of adenine nucleotides (ATP, ADP and AMP) in red blood cell (RBC) by a validated HPLC. The study has shown isoproterenol induced 50% mortality and also increased RBC concentrations of AMP from 0.04 ± 0.02 to 0.29 ± 0.21 mM at the end of the experiment (p < 0.05). Treatment with 10 mg/kg of DTZ reduced mortality from 50% to <20% and attenuated the increase of RBC concentrations of AMP from +0.25 ± 0.22 in the control rats to +0.072 ± 0.092 mM (p < 0.05). The study concluded that 10 mg/kg of DTZ reduced mortality and breakdown of ATP induced by isoproterenol in rats.

Time course for blood pressure lowering of dihydropyridine calcium channel blockers

BACKGROUND

Calcium channel blockers are a heterogeneous class of drugs, including dihydropyridine and non-dihydropyridine subgroups, commonly used in the treatment of hypertension. A systematic review of the 24-hour time course of the blood pressure-lowering effect has not been published.

OBJECTIVES

To assess how much variation there is in hourly systolic and diastolic blood pressure lowering by dihydropyridine calcium channel blockers over a 24-hour period in people with hypertension aged 18 years or over, with baseline systolic blood pressure of at least 140 mmHg or diastolic blood pressure of at least 90 mmHg, or both.

SEARCH METHODS

We performed electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 1, 2014), MEDLINE (1946 to February 2014), EMBASE (1974 to February 2014), and ClinicalTrials.gov (to February 2014). We also screened references of published studies and reviews to identify additional trials.

SELECTION CRITERIA

We included all randomized, placebo-controlled trials assessing the hourly effects of dihydropyridine calcium channel blockers by ambulatory blood pressure monitoring in adults with hypertension with a follow-up of at least three weeks.

DATA COLLECTION AND ANALYSIS

Two authors independently selected the included trials, evaluated the risk of bias, and analyzed the data.

MAIN RESULTS

We included 16 randomized controlled trials of dihydropyridine calcium channel blockers in this systematic review, with 2768 randomized participants. Drugs studied included amlodipine, lercanidipine, mandipine, nifedipine, and felodipine (all administered once daily) and nicardipine (administered twice daily). We analyzed and presented data by hour post dose. The blood pressure-lowering effect was stable over time; there were no clinically important differences in blood pressure-lowering effect of calcium channel blockers between each hour for either systolic blood pressure (estimated mean hourly differences ranged between 9.45 mmHg and 13.2 mmHg) or diastolic blood pressure (estimated mean hourly differences ranged between 5.85 mmHg and 8.5 mmHg). However, there was a moderate risk of bias for this finding. Once-daily dihydropyridine calcium channel blockers appeared to lower blood pressure by a relatively constant amount throughout the 24-hour dosing interval.

AUTHORS' CONCLUSIONS

Six dihydropyridine calcium channel blockers studied in this review lowered blood pressure by a relatively similar amount each hour over the course of 24 hours. The benefits and harms of this pattern of blood pressure lowering are unknown. Further trials are needed with accurate recording of time of drug intake and with reporting of standard deviation of blood pressure at each hour. We did not attempt to assess adverse effects in this review due to the lack of reporting and the short duration of follow-up.

Point-of-care detection and real-time monitoring of intravenously delivered drugs via tubing with an integrated SERS sensor

We demonstrate an approach for detection, identification, and kinetic monitoring of drugs flowing within tubing, through the use of a plasmonic nanodome array (PNA) surface. The PNA structures are fabricated using a low-cost nanoreplica molding process upon a flexible plastic substrate that is subsequently integrated with a flow cell that connects in series with ordinary intravenous (IV) drug delivery tubing. To investigate the potential clinical applications for point-of-care detection and real-time monitoring, we perform SERS detection of ten pharmaceutical compounds (hydrocodone, levorphanol, morphine, oxycodone, methadone, phenobarbital, dopamine, diltiazem, promethazine, and mitoxantrone). We demonstrate dose-dependent SERS signal magnitude, resulting in detection limits (ng ml(-1)) well below typical administered dosages (mg ml(-1)). Further, we show that the detected drugs are not permanently attached to the PNA surface, and thus our approach is capable of performing continuous monitoring of drug delivery as materials flow through IV tubing that is connected in series with the sensor. Finally, we demonstrate the potential co-detection of multiple drugs when they are mixed together, and show excellent reproducibility and stability of SERS measurements for periods extending at least five days. The capabilities reported here demonstrate the potential to use PNA SERS surfaces for enhancing the safety of IV drug delivery.

Assessment and management of pain, with particular emphasis on central neuropathic pain, in moderate to severe dementia

In patients with dementia, undertreatment of pain, irrespective of its aetiology, is widely recognized; the risk for undertreatment increases with the severity of dementia. We argue, however, that central neuropathic pain is by far the most undertreated type of pain in patients with dementia. Central pain is a type of neuropathic pain that is known to occur in stroke patients and is caused by white matter lesions. Although white matter lesions are also a neuropathological hallmark of dementia, central neuropathic pain has hardly been described in dementia. Therefore, the goal of this review was to address assessment and management of pain, with particular emphasis on central neuropathic pain, in moderate to severe dementia. Concerning pain assessment, the findings of this review suggest that self-report pain rating scales, in particular the Verbal Rating Scale, the Horizontal Visual Analogue Scale and the Faces Pain Scale can be administered to patients in a more advanced stage of dementia. For those who are no longer able to communicate pain, pain observation scales are most appropriate. Self-report and pain observation should be combined, if possible. For an overview of assessment tools to measure pain with older people unable to verbally communicate, we refer readers to the City of Hope Pain and Palliative Care Resource Center ( http://prc.coh.org/PAIN-NOA.htm ). The review further highlights that behavioural disturbances, e.g. agitation and physical inactivity, as well as autonomic responses, e.g. an increase in blood pressure and heart rate, may contribute to a more reliable assessment of pain. With respect to central neuropathic pain in particular, assessment of sensory abilities (touch, pinprick, temperature and vibration), mood (e.g. anxiety) and determination of the presence of a Babinsky reflex, accelerated tendon reflexes, and spasticity may contribute to reliable assessment. Management of pain, not of a central origin, starts with paracetamol (acetaminophen), which, together with opioids, is the most frequently prescribed analgesic drug in dementia. Non-steroidal anti-inflammatory drugs are hardly prescribed in a residential setting. Some authors advise starting treatment with a low dose of opioids. Antidepressants and antiepileptic drugs appear to have a positive effect on central neuropathic pain. In the review, advantages and disadvantages of amitriptyline, carbamazepine, lamotrigine, gabapentin and pregabalin are discussed; a negative effect of these drugs on liver and kidney functions, as well as on cognitive functions in patients who already suffer from cognitive impairment is highlighted. Next to pharmacotherapy, non-pharmacological treatment strategies such as transcutaneous electrical nerve stimulation may be effective as long as afferent pathways transmitting the electrical stimulus are still intact.

Autonomic responses to pain in aging and dementia

Increasing age and dementia are accompanied by an increased risk for undertreatment of pain owing to difficulty in assessing pain. Registration of autonomic responses to pain may contribute to a more reliable pain assessment. The aim of this review was to gain more insight into autonomic responses to pain in older persons with and without dementia. Literature searches were performed in the online databases MEDLINE and Web of Science. Seven studies on autonomic responses to pain in older people with or without dementia were included in the review. Autonomic responses to pain are present in older people with and without dementia, although they may be attenuated. Because no distinction could be made between different dementia subtypes based on these studies, predictions of changes in autonomic responses to pain have been made based on neuropathological changes. It can be concluded that autonomic responses to pain are attenuated in older people with and without dementia. Studies to specify the changes in the different autonomic responses for the different dementia subtypes are needed.

Comparing pharmacokinetics and metabolism of diltiazem in normotensive Sprague Dawley and Wistar Kyoto rats vs. spontaneously hypertensive rats in vivo

BACKGROUND

In order to identify a suitable rodent model for preclinical study of calcium antagonists, the pharmacokinetics and metabolism of one of the prototypes diltiazem (DTZ) in normotensive Sprague Dawley (SDR) was compared with Wistar Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) following 5 mg/kg twice daily for five doses given by subcutaneous injection.

METHODS

Pharmacokinetic data were analyzed by standard procedures assuming a one-compartment model with first-order input using Rstrips(®), and differences between the groups were considered significant when p<0.05.

RESULTS

Plasma concentrations of DTZ were higher in the SHR than the normotensive SDR and WKY rats, although the differences did not reach statistical significance (p>0.05). Plasma concentrations of the active metabolites N-desmethyl DTZ (MA), deacetyl DTZ (M1) and deacetyl N-desmethyl DTZ (M2) were significantly higher in the SHR and WKY rats than the SDR, which was attributed to higher DTZ concentrations and also genetic factors.

CONCLUSIONS

Although the differences were mainly quantitative and very small, the study has shown for the first time that the metabolism profiles of DTZ in SHR and WKY rats were closer to humans than SDR, and they may be more preferable rat models to study pharmacokinetic and metabolism studies of DTZ or similar agents.

Combination therapy with amlodipine/valsartan in essential hypertension: a 52-week, randomised, open-label, extension study

BACKGROUND

A majority of hypertensive patients require > or = 2 agents to achieve target blood pressure (BP).

METHODS

This 52-week, multicentre, open-label, randomised extension trial to a previously reported double-blind, placebo-controlled study evaluated the safety and efficacy of amlodipine/valsartan (Aml/Val) combination. Patients who successfully completed the core study without serious drug-related adverse events (AEs) and mean sitting systolic BP (MSSBP)/mean sitting diastolic BP (MSDBP) < or = 150/95 mmHg were eligible to enter the extension and be treated with Aml/Val 2.5/80 or 5/80 mg. After 4 weeks of treatment, patients underwent force-titration to receive 5/160 mg (low dose) or 10/160 mg (high dose) for 48 weeks. Addition of hydrochlorothiazide (HCTZ) 12.5 mg was permitted if BP was > or = 140/90 mmHg at Week 8 or later. Patients could be down-titrated to the prior lower combination dose with or without HCTZ if an intolerable AE occurred. Safety evaluations included monitoring of AEs. Efficacy variables were change from baseline in MSDBP (primary) and MSSBP (secondary).

RESULTS

Of 1246 patients randomised, 1075 (86.3%) completed the extension study. At week 52 end-point, change in MSSBP/MSDBP from core study baseline was -22.1/-17.2 mmHg for low-dose regimen and -22.8/-18.1 mmHg for high-dose regimen. For both regimens, reductions in BP were sustained over 52 weeks and mean BP maintained below approximately 135/85 mmHg at all visits. Frequent AEs in the low- and high-dose regimens were peripheral oedema (9.7% and 17.1% respectively), nasopharyngitis (8.1% and 7.2%), and dizziness (5.2% and 7.0%). Incidence of serious AEs was 3.7% with low dose and 4.1% with high dose.

CONCLUSION

The combination of Aml/Val with the optional addition of HCTZ produced clinically significant and persistent reductions in BP over 52 weeks with a favourable tolerability profile.

Cochlospermum vitifolium induces vasorelaxant and antihypertensive effects mainly by activation of NO/cGMP signaling pathway

AIM OF THE STUDY

Cochlospermum vitifolium is a medicinal plant used for the treatment of diabetes, hepatobilary and cardiovascular illnesses. The aim of current study was to determine the in vivo antihypertensive and in vitro functional vasorelaxant mechanism of methanol extract of Cochlospermum vitifolium (MECv) and naringenin (NG).

MATERIALS AND METHODS

Test material was assayed on rat isolated aorta rings test with- and without-endothelium to determine their vasorelaxant mechanism. Also, the in vivo antihypertensive effect was evaluated on spontaneously hypertensive rat (SHR) model. In addition, presence of NG into the extract was confirmed by reverse phase high performance liquid chromatography (RP-HPLC) analysis.

RESULTS

MECv (120 mg/kg) and NG (50 and 160 mg/kg) showed acute antihypertensive effects on SHR when systolic and diastolic pressure were decreased at 1 h and 24 h after administration, respectively. Vasorelaxant effect of MECv and NG was shifted to the right when endothelium-intact aortic rings were pre-incubated with L-NAME (10 microM) and ODQ (1 microM). Also, NG relaxant curves were displaced to the right in the presence of tetraethylammonium (TEA, 1 mM) and 2-aminopyridine (2-AP, 100 microM) on endothelium-denuded aortic rings.

CONCLUSION

Experiments described above showed that MECv play an important role in hypertension regulation through NO synthesis and may be PGI(2) production and potassium channel activation on excessive endothelial dysfunction conditions. Unfortunately, presence of NG into the extract is not significant on bioactivity of the extract; however, this compound could be tested and evaluated as structural scaffold for future drug design for development of antihypertensive agents.

Principal component analysis of HPLC retention data and molecular modeling structural parameters of cardiovascular system drugs in view of their pharmacological activity

Evaluation of relationships between molecular modeling structural parameters and high-performance liquid chromatography (HPLC) retention data of 11 cardiovascular system drugs by principal component analysis (PCA) in relation to their pharmacological activity was performed. The six retention data parameters were determined on three different HPLC columns (Nucleosil C18 AB with octadecylsilica stationary phase, IAM PC C10/C3 with chemically bounded phosphatidylcholine, and Nucleosil 100-5 OH with chemically bounded propanodiole), and using isocratically acetonitrile: Britton-Robinson buffer as the mobile phase. Additionally, molecular modeling studies were performed with the use of HyperChem software and MM+ molecular mechanics with the semi-empirical AM1 method deriving 20 structural descriptors. Factor analysis obtained with the use of various sets of parameters: structural parameters, HPLC retention data, and all 26 considered parameters, led to the extraction of two main factors. The first principal component (factor 1) accounted for 44–57% of the variance in the data. The second principal component (factor 2) explained 29–33% of data variance. Moreover, the total data variance explained by the first two factors was at the level of 73–90%. More importantly, the PCA analysis of the HPLC retention data and structural parameters allows the segregation of circulatory system drugs according to their pharmacological (cardiovascular) properties as shown by the distribution of the individual drugs on the plane determined by the two principal components (factors 1 and 2).

Efficacy and safety of a single-pill combination of amlodipine/valsartan in Asian hypertensive patients inadequately controlled with amlodipine monotherapy

OBJECTIVE

The antihypertensive efficacy of amlodipine/valsartan combination has not been evaluated in Asian patients as previous large-scale studies enrolled very few patients. This multicentre, randomised, double-blind study assessed the efficacy and safety of a single-pill combination of amlodipine/valsartan versus amlodipine in Asian hypertensive patients.

METHODS

After a 1-4-week washout period, patients (mean sitting diastolic BP [msDBP]: >or=95-<110 mmHg) were treated with amlodipine 5 mg for 4 weeks. Patients inadequately controlled on amlodipine (msDBP >or=90 and <110 mmHg) were randomised to receive amlodipine/valsartan 5/80 mg (n = 349) or amlodipine 5 mg (n = 349) for 8 weeks. Efficacy variables were change in msDBP, mean sitting systolic BP (msSBP) from baseline (at randomisation) to week 8 endpoint, and BP control rate (<140/90 mmHg) at week 8 endpoint. Safety assessments included monitoring and recording of adverse events (AEs).

RESULTS

Baseline characteristics were comparable between the groups. Most patients were Chinese (86.4%), men (65.1%), with a baseline BP 139.5/94.5 mmHg. At week 8 endpoint, the least square mean reduction in BP was significantly greater with amlodipine/valsartan combination than amlodipine monotherapy (-11.4/-9.7 vs. -7.4/-7.1 mmHg; p < 0.0001) with a higher BP control rate (69.2 vs. 57.6%; p = 0.0013). Ambulatory BP monitoring in a subgroup of patients (n = 82), showed a significant 24-h mean BP reduction from baseline with amlodipine/valsartan (-7.3/-6.3 mmHg; p < 0.0001), whereas the reduction was not significant with amlodipine (-0.2/+0.3 mmHg; p > 0.05). The overall incidence of AEs was similar in both groups. Peripheral oedema occurred only in the amlodipine group n = 4 (1.1%) and not in the amlodipine/valsartan combination. Hypotension was reported in only one patient in the amlodipine/valsartan combination. Six patients (0.9%) experienced serious AEs, of which only one SAE, i.e. gastric ulcer, was reported to be related to amlodipine treatment.

CONCLUSION

The single-pill combination of amlodipine/valsartan was efficacious and well-tolerated in Asian hypertensive patients who were inadequately controlled on amlodipine alone. As with all clinical trials, the entry criteria may limit the extrapolation of these results to a broader population. ClinicalTrials.gov Identifier: NCT00413049.

Efficacy of amlodipine and olmesartan medoxomil in patients with hypertension: the AZOR Trial Evaluating Blood Pressure Reductions and Control (AZTEC) study

The aim of the present study was to use ambulatory blood pressure (BP) monitoring (ABPM) to determine the efficacy of a fixed-dose combination of amlodipine (AML) and olmesartan medoxomil (OM) over the 24-hour dosing interval. This 12-week, titrate-to-goal study was conducted in 185 patients with hypertension. Patients were initially treated with AML 5 mg/ day and uptitrated to AML/OM 5/20, 5/40, and 10/40 mg/day every 3 weeks if mean seated BP (SeBP) was ≥120/80 mmHg. The primary efficacy endpoint was the change from baseline in mean 24-hour systolic BP at week 12 as assessed by ABPM. At baseline, the mean 24-hour ambulatory BP (±standard deviation [SD]) was 144.8±11.1/85.7±7.9 mmHg. At week 12, the change from baseline in mean 24-hour ambulatory BP (±standard error of the mean [SEM]) was -21.4±0.8/-12.7±0.5 mmHg (p < 0.0001 versus baseline). At baseline, the mean SeBP (±SD) was 158.2±12.6/92.8±8.6 mmHg and at week 12, the mean SeBP change (±SEM) from baseline (last observation carried forward) was -24.1±1.1/-12.1±0.7 mmHg (p < 0.0001 versus baseline). Proportions of patients achieving mean 24-hour ambulatory BP prespecified study targets were 70.9% (<130/80 mmHg), 48.3% (<125/75 mmHg), and 40.7% (<120/80 mmHg). Cumulatively, 76.8% of patients uptitrated to AML/OM 10/40 mg/day attained an SeBP goal of <140/90 mmHg. The study drug was well tolerated with few adverse events (peripheral edema, 2.2%; dizziness, 1.1%). An AML/OM-based titration regimen effectively reduces BP in patients with hypertension.

CaV1.3 L-type Ca2+ channels modulate depression-like behaviour in mice independent of deaf phenotype

Mounting evidence suggests that voltage-gated L-type Ca2+ channels can modulate affective behaviour. We therefore explored the role of CaV1.3 L-type Ca2+ channels in depression- and anxiety-like behaviours using CaV1.3-deficient mice (CaV1.3-/-). We showed that CaV1.3-/- mice displayed less immobility in the forced swim test as well as in the tail suspension test, indicating an antidepressant-like phenotype. Locomotor activity in the home cage or a novel open-field test was not influenced. In the elevated plus maze (EPM), CaV1.3-/- mice entered the open arms more frequently and spent more time there indicating an anxiolytic-like phenotype which was, however, not supported in the stress-induced hyperthermia test. By performing parallel experiments in Claudin 14 knockout mice (Cldn14-/-), which like CaV1.3-/- mice are congenitally deaf, an influence of deafness on the antidepressant-like phenotype could be ruled out. On the other hand, a similar EPM behaviour indicative of an anxiolytic phenotype was also found in the Cldn14-/- animals. Using electroretinography and visual behavioural tasks we demonstrated that at least in mice, CaV1.3 channels do not significantly contribute to visual function. However, marked morphological changes were revealed in synaptic ribbons in the outer plexiform layer of CaV1.3-/- retinas by immunohistochemistry suggesting a possible role of this channel type in structural plasticity at the ribbon synapse. Taken together, our findings indicate that CaV1.3 L-type Ca2+ channels modulate depression-like behaviour but are not essential for visual function. The findings raise the possibility that selective modulation of CaV1.3 channels could be a promising new therapeutic concept for the treatment of mood disorders.

Efficacy and tolerability of amlodipine/valsartan combination therapy in hypertensive patients not adequately controlled on amlodipine monotherapy

ABSTRACT (ARB), in essential hypertensive patients not adequately controlled by amlodipine monotherapy.

METHODS

This was a multi-centre, randomised, double-blind, active-controlled study in patients with essential hypertension. After a washout period followed by a single-blind amlodipine 10 mg run-in period, patients with mean sitting diastolic blood pressure (msDBP) > or =90 mmHg and <110 mmHg were randomised to receive amlodipine/valsartan (10/160 mg o.d.) or amlodipine (10 mg o.d.) for 8 weeks.

TRIAL REGISTRATION NUMBER

NCT00171002.

MAIN OUTCOME MEASURES

The primary efficacy variable was change from baseline in msDBP at study endpoint. Secondary efficacy variables were change from baseline in mean sitting systolic blood pressure (msSBP), responder rate (msDBP <90 mmHg or > or =10 mmHg reduction from baseline) and DBP control rate (msDBP <90 mmHg).

RESULTS

Of the 1283 patients enrolled in single-blind period, 944 were randomised to receive amlodipine/valsartan 10/160 mg (n = 473) and amlodipine 10 mg (n = 471). Statistically significant greater reductions (p < 0.0001) from baseline in msSBP/msDBP were observed with combination therapy (12.9/11.4 mmHg) compared to monotherapy (10.0/9.3 mmHg). Responder rate was significantly greater (p = 0.0011) with combination therapy (79.0%) compared to monotherapy (70.1%). The percentage of patients with controlled DBP was also significantly (p < 0.0001) higher with combination therapy (77.8%) compared to monotherapy (66.5%). Incidence of peripheral oedema was slightly higher with amlodipine monotherapy (9.4%) compared to combination therapy (7.6%).

CONCLUSION

The combination of amlodipine/valsartan in this 8-week double-blind study provided additional BP control and was well tolerated in patients inadequately controlled with amlodipine monotherapy. Results should be interpreted with the knowledge that study entry criteria may limit application to a wider population.

Patient adherence and the choice of antihypertensive drugs: focus on lercanidipine

Despite the development of many effective antihypertensive drugs, target blood pressures are reached in only a minority of patients in clinical practice. Poor adherence to drug therapy and the occurrence of side effects are among the main reasons commonly reported by patients and physicians to explain the poor results of actual antihypertensive therapies. The development of new effective antihypertensive agents with an improved tolerability profile might help to partly overcome these problems. Lercanidipine is an effective dihydropyridine calcium channel blocker of the third generation characterized by a long half-life and its lipophylicity. In contrast to first-generation dihydropyridines, lercanidipine does not induce reflex tachycardia and induces peripheral edema with a lower incidence. Recent data suggest that in addition to lowering blood pressure, lercanidipine might have some renal protective properties. In this review we shall discuss the problems of drug adherence in the management of hypertension with a special emphasis on lercanidipine.

Angiotensin receptor blocker and dihydropyridine calcium channel blocker combinations: an emerging strategy in hypertension therapy

Hypertension is a leading contributor to the burden of cardiovascular disease. The importance of lowering blood pressure (BP) to reduce the risk of cardiovascular events has been demonstrated in numerous clinical trials. Most patients require combination antihypertensive therapy utilizing agents from complementary drug classes to achieve BP goals. A calcium channel blocker (CCB)/angiotensin receptor blocker (ARB) combination is a rational approach for such an antihypertensive strategy. Benefits of CCB/ARB combination therapy include additive BP-lowering effects and lower incidences of adverse events (AEs). These agents demonstrate benefits associated with their respective drug classes. The ARBs confer stroke protection, renal protection, and tolerability similar to placebo, without dose-related symptomatic and metabolic AEs, while CCBs are beneficial in reducing stroke and treating angina and cardiac ischemia. The efficacy of this combination has been recently investigated in clinical trials wherein amlodipine was combined with olmesartan medoxomil or valsartan. This article discusses the rationale for using CCB/ARB combinations in patients with hypertension.

Complementary mechanisms of angiotensin receptor blockers and calcium channel blockers in managing hypertension

Hypertension affects approximately 73 million individuals in the United States. Clinical studies have shown that antihypertensive therapy can reduce blood pressure (BP) and the risk of cardiovascular events. However, the majority of patients with hypertension do not achieve the recommended BP goal of < 140/90 mm Hg (or < 130/80 mm Hg for patients with diabetes) with antihypertensive monotherapy, and require therapy with 2 or more antihypertensive agents. Combination therapy utilizes antihypertensive agents from different drug classes, which act via distinct pharmacologic mechanisms to improve overall efficacy and tolerability. Although combination therapy is superior to monotherapy in achieving BP goals across the entire spectrum of hypertension, the proportion of patients achieving the recommended BP goal can be further improved by the use of new antihypertensive drug combinations. The beneficial antihypertensive characteristics of both angiotensin receptor blockers and calcium channel blockers suggest that combining these classes may result in a highly efficacious antihypertensive therapy with regard to both activity and safety when used as a fixed-dose combination. In particular, a fixed-dose combination of olmesartan medoxomil plus amlodipine besylate has been demonstrated to be an efficacious antihypertensive combination due in part to the benefits associated with each of these agents within their respective drug classes.

The combination of amlodipine/valsartan 5/160 mg produces less peripheral oedema than amlodipine 10 mg in hypertensive patients not adequately controlled with amlodipine 5 mg

AIMS

To demonstrate the benefit of the combination amlodipine/valsartan 5/160 mg over amlodipine 10 mg, in producing a lower incidence of peripheral oedema for a comparable mean sitting systolic blood pressure (MSSBP) reduction.

METHODS

After a 4-week amlodipine 5 mg run-in phase, inadequately controlled hypertension patients (aged > or = 55 years, MSSBP > or = 130 and < or = 160 mmHg) were randomised to receive amlodipine/valsartan 5/160 mg or amlodipine 10 mg for 8 weeks, followed by amlodipine/valsartan 5/160 mg for 4 weeks for all patients. Primary variables were MSSBP change from baseline to week 8 and incidence of peripheral oedema reported as an AE. Resolution of peripheral oedema was assessed 4 weeks after switching patients from amlodipine 10 mg to amlodipine/ valsartan 5/160 mg.

RESULTS

At week 8, MSSBP showed greater reduction with amlodipine/valsartan 5/160 mg than amlodipine 10 mg (least square mean: -8.01 vs.-5.95 mmHg, p < 0.001 for non-inferiority and p = 0.002 for superiority). Systolic control, overall BP control and systolic response rate at week 8 were significantly higher with combination than amlodipine 10 mg (34 vs. 26%; 57 vs. 50%; 36.57 vs. 27.77%, respectively). Incidence of peripheral oedema was significantly lower with the combination than amlodipine 10 mg (6.6 vs. 31.1%, p < 0.001). Peripheral oedema resolved in 56% patients who switched from amlodipine 10 mg to the combination, without the loss of effect on BP reduction.

CONCLUSION

In non-responders to amlodipine 5 mg, treatment with amlodipine/valsartan 5/160 mg induced significantly less peripheral oedema than amlodipine 10 mg for similar BP reduction. Peripheral oedema resolved in > 50% patients switching from amlodipine 10 mg to the combination.

Efficacy and tolerability of amlodipine/valsartan combination therapy in hypertensive patients not adequately controlled on valsartan monotherapy

OBJECTIVE

To demonstrate additional BP-lowering effects of amlodipine/valsartan combination in patients whose BP was not adequately controlled on valsartan alone.

METHODS

This was a multi-centre, randomised, double-blind, active-controlled study in patients with essential hypertension. After a washout period followed by a single-blind valsartan 160 mg run-in period, patients with mean sitting diastolic blood pressure (DBP) >or= 90 mmHg and < 110 mmHg were randomised to receive amlodipine/valsartan (10/160 mg or 5/160 mg o.d.) or valsartan (160 mg o.d.) for 8 weeks.

TRIAL REGISTRATION

NCT00170963 MAIN OUTCOME MEASURES: Primary efficacy variable was change from baseline in mean DBP at study end. Secondary efficacy variables included change from baseline in mean sitting systolic blood pressure (SBP), responder rate (mean DBP < 90 mmHg or >or= 10 mmHg reduction from baseline), and DBP control rate (mean DBP < 90 mmHg). Safety was also assessed.

RESULTS

Of 1136 patients enrolled in single-blind phase, 947 (mean age: 54.6 years) were randomised. Statistically significantly greater reductions in mean SBP/DBP were observed in both amlodipine/valsartan combinations (10/160 mg: 14.3/11.5 mmHg, 5/160 mg: 12.2/9.6 mmHg; both p < 0.0001) compared to valsartan 160 mg (8.3/6.7 mmHg). The 10/160 mg combination (p < 0.05) showed statistically significantly greater reductions in mean SBP/DBP compared to 5/160 mg (p < 0.001). Responder rates were higher in both combination therapy groups (10/160 mg: 81% [p < 0.0001]; 5/160 mg: 68% [p = 0.0018], respectively) compared to monotherapy (57%). Peripheral oedema was the most frequent adverse event, reported in amlodipine/valsartan 10/160 mg (9.1%), 5/160 mg (0.9%), and valsartan 160 mg (1.3%).

CONCLUSIONS

The combination of amlodipine/valsartan in this 8-week double-blind study provided additional BP control and was well-tolerated in patients inadequately controlled with valsartan monotherapy.

Olmesartan/Amlodipine: combination therapy for the treatment of hypertension [corrected]

Hypertension is a highly prevalent disease and one of the most important modifiable risk factors for cardiovascular disease. Hypertension remains the leading cause of mortality and the third largest cause of disability in both developed and developing countries. Although recent guidelines and advisory statements are recommending lower thresholds and goals for antihypertensive treatment, approximately two thirds of patients do not achieve the goals. In the United States only 36.8% of hypertensive patients achieve the goal of <140/90 mmHg. Poor adherence to antihypertensive medication regimens contributes to the practice-outcome gap. In most hypertensive patients it is difficult or impossible to control blood pressure with one drug, thus current guidelines have recommended the use of combination therapy as first-line treatment, or early in the management of hypertension. Blocking two or more blood pressure regulatory systems provides a more effective and more physiologic reduction in blood pressure. Fixed-dose combinations offer many advantages over free-drug combinations, such as convenience of use, fewer adverse events, and greater antihypertensive potency. Similar to other combinations, fixed-dose combination tablets containing the dihydropyridine calcium channel blocker amlodipine and the angiotensin receptor blocker olmesartan bring together two distinct and complementary mechanisms of action, resulting in improved blood pressure control and potential for improved target organ protection relative to either class of agent alone.

Effective and safe reduction of blood pressure with the combination of amlodipine 5 mg and valsartan 160 mg in hypertensive patients not controlled by calcium channel blocker monotherapy

INTRODUCTION

The addition of an angiotensin II receptor blocker to calcium channel blocker-based antihypertensive therapy may be associated with enhanced efficacy and reduced risk of adverse events.

METHODS

This 8-week, open-label, single-arm trial evaluated the efficacy and tolerability of the combination of amlodipine and valsartan in patients not responding adequately to treatment with amlodipine or felodipine alone. Patients aged > or =18 years with moderate essential hypertension (defined as mean sitting systolic blood pressure [MSSBP] > or =160 and <180 mmHg) were treated for 4 weeks with once-daily amlodipine 5 mg or felodipine 5 mg. At week 4, patients not adequately responding were treated for an additional 4 weeks with once-daily amlodipine 5 mg plus valsartan 160 mg. Of 214 patients treated for 4 weeks with amlodipine 5 mg or felodipine 5 mg, 181 failed to achieve MSSBP <140 mmHg. These non-responders were treated for an additional 4 weeks with amlodipine 5 mg and valsartan 160 mg.

RESULTS

A clinically and statistically significant additional reduction in MSSBP of 13.1 mmHg (95% confidence interval [CI]: 11.4, 14.7; P<0.0001) and a mean sitting diastolic blood pressure of 5.3 mmHg (95% CI: 4.3, 6.3; P<0.0001) were observed. Of patients treated with amlodipine 5 mg and valsartan 160 mg, 51.1% achieved target blood pressure levels (<140/90 mmHg) after 4 weeks. Adverse event rates were low in both treatment phases, and most were mild or moderate in severity.

CONCLUSION

The combination of amlodipine/valsartan was effective and well tolerated.

Pharmacokinetics and metabolism of diltiazem in rats: comparing single vs repeated subcutaneous injections in vivo

The objective of the study was to determine the effect of repeated administration on the pharmacokinetics and metabolism of diltiazem (DTZ) using an in vivo rat model. Male SD rats (n = 6-10 per group) weighing 350-450 g were used. Each rat received either a single 20 mg/kg dose of DTZ by subcutaneous (s.c.) injection or 5 mg/kg s.c. twice daily for five doses. Plasma concentrations of DTZ and its major metabolites were determined by HPLC for up to 8 h. Compared with the single dose, repeated administration resulted in higher dose normalized plasma concentrations of DTZ (AUC 26.4+/-14.2 vs 13.9+/-11.5 microg-h/ml), longer apparent half-life (t(1/2) = 12.5+/-14.6 vs 3.7+/-1.4 h) and lower systemic clearance (CL = 1.1+/-1.0 vs 2.9+/-2.7 l/h/kg). Higher dose normalized plasma concentrations, longer t(max), but shorter apparent t(1/2) of the major metabolites were observed following the repeated administration. The results also suggest that possible binding of DTZ may occur at the site of injection when administered subcutaneously in the higher dose.

Fixed combinations in the management of hypertension: patient perspectives and rationale for development and utility of the olmesartan-amlodipine combination

Although the awareness and control of hypertension has increased, only 37% of hypertensive patients in the US achieve the conservative goal of <140/90 mmHg. Achieving optimal blood pressure (BP) control is the most important single issue in the management of hypertension, and in most hypertensive patients, it is difficult or impossible to control BP with one drug. Blocking two or more BP regulatory systems provides a more effective and more physiologic reduction in BP, and current guidelines have recommended the use of combination therapy as first-line treatment, or early in the management of hypertension. Fixed combination therapy is an efficacious, relatively safe, and may be cost-effective method of decreasing BP in most patients with essential hypertension. Similar to other combinations, fixed-dose combination tablets containing the dihydropyridine calcium channel blocker amlodipine and the angiotensin II receptor blocker olmesartan bring together two distinct and complementary mechanisms of action, resulting in improved BP control and potential for improved target organ protection relative to either class of agent alone.

A prospective evaluation of persistence on antihypertensive treatment with different antihypertensive drugs in clinical practice

Persistence on treatment affects the efficacy of antihypertensive treatment. We prospectively investigated the persistence on therapy and the extent of blood pressure (BP) control in 347 hypertensive patients (age 59.4 +/- 6 years) randomly allocated to a first-line treatment with: angiotensin-converting enzyme (ACE) inhibitors, calcium-channel blockers (CCBs), beta-blockers, angiotensin-II receptor blockers (ARBs), or diuretics and followed-up for 24-months. Persistence on treatment was higher in patients treated with ARBs (68.5%) and ACE inhibitors (64.5%) vs CCBs (51.6%; p < 0.05), beta-blockers (44.8%, p < 0.05), and diuretics (34.4%, p < 0.01). No ARB, ACE inhibitor, beta-blocker, or diuretic was associated with a higher persistence in therapy compared with the other molecules used in each therapeutic class. The rate of persistence was significantly higher in patients treated with lercanidipine vs others CCBs (59.3% vs 46.6%, p < 0.05). Systolic and diastolic BP was decreased more successfully in patients treated with ARBs (-11.2/-5.8 mmHg), ACE inhibitors (-10.5/-5.1 mmHg), and CCBs (-8.5/-4.6 mmHg) compared with beta-blockers (-4.0/-2.3 mmHg p < 0.05) and diuretics (-2.3/-2.1 mmHg, p < 0.05). No ARB, ACE inhibitor, beta-blocker, or diuretic was associated with a higher BP control compared with the other molecules used in each therapeutic class. A trend toward a better BP control was observed in response to lercanidipine vs other CCBs (p = 0.059). The present results confirm the importance of persistence on treatment for the management of hypertension in clinical practice.

Two multicenter, 8-week, randomized, double-blind, placebo-controlled, parallel-group studies evaluating the efficacy and tolerability of amlodipine and valsartan in combination and as monotherapy in adult patients with mild to moderate essential hypertension

BACKGROUND

Patients with hypertension may require combination therapy to attain the blood pressure targets recommended by US and European treatment guidelines. Combination therapy with a calcium channel blocker and an angiotensin II-receptor blocker would be expected to provide enhanced efficacy.

OBJECTIVES

Two studies were conducted to compare the efficacy of various combinations of amlodipine and valsartan administered once daily with their individual components and placebo in patients with mild to moderate essential hypertension (mean sitting diastolic blood pressure [MSDBP] >/=95 and < 110 mm Hg). A secondary objective was to evaluate safety and tolerability.

METHODS

The 2 studies were multinational, multicenter, 8-week, randomized, double-blind, placebo-controlled, parallel-group trials. In study 1, patients were randomized to receive amlodipine 2.5 or 5 mg once daily, valsartan 40 to 320 mg once daily, the combination of amlodipine 2.5 or 5 mg with valsartan 40 to 320 mg once daily, or placebo. In study 2, patients were randomized to receive amlodipine 10 mg once daily, valsartan 160 or 320 mg once daily, the combination of amlodipine 10 mg with valsartan 160 or 320 mg once daily, or placebo. The primary efficacy variable in both studies was change from baseline in MSDBP at the end of the study. Secondary variables included the change in mean sitting systolic blood pressure (MSSBP), response rate (the proportion of patients achieving an MSDBP <90 mm Hg or a >/= 10-mm Hg decrease from baseline), and control rate (the proportion of patients achieving an MSDBP <90 mm Hg). Safety was assessed in terms of adverse events (spontaneously reported or elicited by questioning), vital signs, and laboratory values.

RESULTS

A total of 1911 patients were randomized to treatment in study 1 (1022 amlodipine + valsartan; 507 valsartan; 254 amlodipine; 128 placebo); 1250 were randomized to treatment in study 2 (419, 415, 207, and 209, respectively). In all treatment groups in both studies, the majority of patients were white (79.5% study 1, 79.4% study 2) and male (53.5% and 50.3%, respectively). The overall mean age was 54.4 years in study 1 and 56.9 years in study 2. The mean weight of patients in study 1 was higher than that in study 2 (88.8 vs 79.7 kg). The overall baseline mean sitting BP was 152.8/99.3 mm Hg in study 1 and 156.7/99.1 mm Hg in study 2. With the exception of a few combinations that included amlodipine 2.5 mg, the combination regimens in both studies were associated with significantly greater reductions in MSDBP and MSSBP compared with their individual components and placebo (P < 0.05). A positive dose response was observed for all combinations. The highest response rate in study 1 was associated with the highest dose of combination therapy (amlodipine 5 mg + valsartan 320 mg: 91.3%). Amlodipine 5 mg, valsartan 320 mg, and placebo were associated with response rates of 71.9%, 73.4%, and 40.9%, respectively. In study 2, the 2 doses of combination therapy were associated with similar response rates (amlodipine 10 mg + valsartan 160 mg: 88.5%; amlodipine 10 mg + valsartan 320 mg: 87.5%). Amlodipine 10 mg was associated with a response rate of 86.9%; valsartan 160 and 20 mg were associated with response rates of 74.9% and 72.0%, respectively; and placebo was associated with a response rate of 49.3%. Control rates followed a similar pattern. The incidence of peripheral edema with combination therapy was significantly lower compared with amlodipine monotherapy (5.4% vs 8.7%, respectively; P = 0.014), was significantly higher compared with valsartan monotherapy (2.1%; P < 0.001), and did not differ significantly from placebo (3.0%).

CONCLUSIONS

In these adult patients with mild to moderate hypertension, the combination of amlodipine + valsartan was associated with significantly greater blood pressure reductions from baseline compared with amlodipine or valsartan monotherapy or placebo. The incidence of peripheral edema was significantly lower with combination therapy than with amlodipine monotherapy.

Modified-release nifedipine: a review of the use of modified-release formulations in the treatment of hypertension and angina pectoris

Nifedipine is a dihydropyridine calcium channel antagonist with predominantly vasodilatory activity. Modified-release formulations of nifedipine are effective antihypertensive and antianginal therapies and are generally well tolerated. Among the available formulations, those that produce a gradual increase in plasma nifedipine concentration, which is then sustained over a 24-hour period, are preferred, as they cause a gradual onset of vasodilatation and avoid baroreflex sympathetic activation (for example, nifedipine gastrointestinal therapeutic system [GITS] and a Japanese controlled-release formulation). Modified-release nifedipine had beneficial effects on a number of markers of vascular function, and nifedipine GITS reduced the need for coronary procedures in patients with coronary artery disease. In patients with hypertension, nifedipine GITS and nifedipine retard had beneficial effects on the overall incidence of major cardiovascular events, as did nifedipine retard in patients with concurrent hypertension and coronary artery disease.

The ASCOT trial: clarifying the role of ACE inhibition in the reduction of cardiovascular events in patients with hypertension

Hypertension remains one of the primary causes of preventable death in developed countries. Universally accepted clinical practice guidelines based on well designed trials are needed to ensure standardized treatment for these patients. It has been hypothesized that agents such as calcium channel antagonists and ACE inhibitors may be more effective than beta-adrenoceptor antagonist (beta-blocker)- or diuretic-based regimens. However, until recently, there have been limited data on the efficacy of 'newer' antihypertensive regimens, particularly combination therapy, relative to standard therapeutic options. The ASCOT-BPLA (Anglo-Scandinavian Cardiac Outcomes Trial-Blood Pressure Lowering Arm), a prospective, randomized, controlled trial in >19 250 patients with hypertension, highlights the benefit of a combined amlodipine plus perindopril regimen over an atenolol plus diuretic-based combination in terms of significant reductions (p < 0.05) in all-cause mortality, total cardiovascular events and procedures, and fatal and nonfatal stroke. The ASCOT-BPLA trial underlines the cardiovascular benefit of ACE inhibitors, specifically perindopril, beyond that provided by BP reduction, and potentially reflects a mechanistic feature of the ACE inhibitors. It also suggests that the combination of amlodipine plus perindopril may provide broad-spectrum cardiovascular protection, as well as reduce the incidence of new-onset diabetes mellitus and renal impairment, in addition to its efficacy in lowering BP. The ASCOT-BPLA trial provides evidence of the need to reconsider traditional prescribing recommendations in patients with hypertension, particularly conclusions reached in the US after the publication of the ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial) study. The recently published National Institute for Health and Clinical Excellence (NICE) guidelines in the UK emphasize the efficacy of ACE inhibitors as first-line agents for hypertensive patients <55 years of age and recommend ACE inhibitor therapy at any stage of hypertension management.