Duration of Vasodilatory Action After Intra-arterial Infusions of Calcium Channel Blockers in Animal Model of Cerebral Vasospasm

BACKGROUND

In medically refractory vasospasm, invasive intervention may be required. A commonly used approach is intra-arterial (IA) drug infusion. Although calcium channel blockers (CCBs) have been widely applied in this setting, studies comparing their efficacies and durations of action have been few. This study was performed to compare attributes of three CCBs (nicardipine, nimodipine, and verapamil), focusing on duration of the vasodilatory action based on angiography.

METHODS

Vasospasm was produced in New Zealand white rabbits (N = 22) through experimentally induced subarachnoid hemorrhage and confirmed in each via conventional angiography, grouping them by IA-infused drug. After chemoangioplasty, angiography was performed hourly for 5 h to compare dilated and vasospastic arterial diameters. Drug efficacy, duration of action, and changes in mean arterial pressure (relative to baseline) were analyzed by group.

RESULTS

Effective vasodilation was evident in all three groups immediately after IA drug infusion. The vasodilative effects of nimodipine and nicardipine peaked at 1 h and were sustained at 2 h, returning to initial vasospastic states at 3 h. In verapamil recipients, effects were more transient by comparison, entirely dissipating at 1 h. Only the nicardipine group showed a significant 3-h period of lowered blood pressure.

CONCLUSIONS

Although nimodipine and nicardipine proved longer acting than verapamil in terms of vasodilation, their effects were not sustained beyond 2 h after IA infusion. Further study is required to confirm the vasodilatory duration of IA CCB based on perfusion status, and an effort should be made to find new alternative to extend the duration.

Ca2+ channel dynamics explain the nonlinear neuroplasticity induction by cathodal transcranial direct current stimulation over the primary motor cortex

Transcranial direct current stimulation (tDCS) induces polarity-dependent neuroplasticity: with conventional protocols, anodal tDCS results in excitability enhancement while cathodal stimulation reduces excitability. However, partially non-linear responses are observed with increased stimulation intensity and/or duration. Cathodal tDCS with 2 mA for 20 min reverses the excitability-diminishing plasticity induced by stimulation with 1 mA into excitation, while cathodal tDCS with 3 mA again results in excitability diminution. Since tDCS generates NMDA receptor-dependent neuroplasticity, such non-linearity could be explained by different levels of calcium concentration changes, which have been demonstrated in animal models to control for the directionality of plasticity. In this study, we tested the calcium dependency of non-linear cortical plasticity induced by cathodal tDCS in human subjects in a placebo controlled, double-blind and randomized design. The calcium channel blocker flunarizine was applied in low (2.5 mg), medium (5 mg) or high (10 mg) dosages before 20 min cathodal motor cortex tDCS with 3 mA in 12 young healthy subjects. After-effects of stimulation were monitored with TMS-induced motor evoked potentials (MEPs) until 2 h after stimulation. The results show that motor cortical excitability-diminishing after-effects of stimulation were unchanged, diminished, or converted to excitability enhancement with low, medium and high dosages of flunarizine. These results suggest a calcium-dependency of the directionality of tDCS-induced neuroplasticity, which may have relevant implications for future basic and clinical research.

Calcium channel blocker induced gingival enlargement following implant placement in a fibula free flap reconstruction of the mandible: a case report

Background

Gingival tissue enlargement is a common side effect of antiepileptic medications (e.g. phenytoin and sodium valproate), immunosuppressing drugs (e.g. cyclosporine) and calcium channel blockers (e.g. nifedipine, verapamil, amlodipine) (Murakami et al. 2018, Clin Periodontol 45:S17–S27, 2018). The clinical and histological appearances of lesions caused by these drugs are indistinguishable from one another (Murakami et al. 2018, Clin Periodontol 45:S17–S27, 2018). Drug-induced gingival enlargement is rarely seen in edentulous patients.

Case presentation

This case presents a 72-year-old female with a history of squamous cell carcinoma of the floor of the mouth treated with surgical excision and fibula-free flap reconstruction. Following the uncovering of osseointegrated implants placed in the fibular-free flap, the patient developed gingival enlargement of the floor of the mouth. Cessation of amlodipine and switching to an alternative medication lead to a resolution of the enlarged tissue.

Conclusions

This case illustrates that gingival enlargement can occur around dental implants, most notably in rehabilitation cases in patients who have had head and neck cancer. Clinicians should be aware of the risk of gingival enlargement in hypertensive patients taking calcium channel blockers prior to implant placement.

Therapeutic Potential of Dihydropyridine Calcium Channel Blockers on Oxidative Injury Caused by Organophosphates in Cortex and Cerebellum: An In Vivo Study

This study was designed to investigate the effects of amlodipine (AM), a dihydropyridine calcium channel blocker, on the oxidative damage induced by diazinon (DZN) in the rat cortex and cerebellum. Forty-two rats were randomly divided into six groups. The rats were treated intraperitoneally with normal saline (group 1), AM (9 mg/kg; group 2), DZN (32 mg/kg; group 3) and different doses of AM (3, 6, and 9 mg/kg; groups 4, 5, and 6, respectively) with DZN. After 14 days, the cerebellum and cortex tissues were removed for biochemical and histological experiments. DZN significantly decreased acetylcholinesterase activity (AChE; 57%, p < 0.001 and 39.1%, p < 0.05), depleted total antioxidant capacity (TAC; 46.2%, p < 0.01 and 44.7%, p < 0.05), and increased lactate dehydrogenase activity (LDH; 96%, p < 0.001 and 202%, p < 0.001), nitric oxide (NO; 130%, p < 0.001 and 74.4%, p < 0.001), and lipid peroxidation levels (LPO; 35.6%, p < 0.001 and 128.7%, p < 0.001), in the cerebellum and cortex tissues, respectively. In addition, DZN induced structural alterations in the cerebellum and cortex. Following AM administration, a remarkable improvement was observed in LDH activity and some of the oxidative markers, such as NO and LPO; however, no significant changes were found in AChE activity when the DZN group was compared with the AM-treated groups. This study suggests that AM may prevent DZN-induced neurotoxicity via improvement of the oxidative/antioxidant balance in the cerebellum and cortex tissues.

Comparison between calcium channel blocker with angiotensin converting enzyme inhibitor or angiotensin II type 1 receptor blocker combination on the development of new-onset diabetes in hypertensive Korean patients

Background and purpose

Rare comparative studies investigated the relationship between combination therapy of antihypertensive drugs and the incidence of new-onset diabetes mellitus (NODM). The aim of this study was to evaluate which combination therapy, calcium channel blocker (CCB) with angiotensin converting enzyme inhibitor (ACEI) or CCB with angiotensin II type 1 receptor blocker (ARB), is best in reducing/preventing the development of NODM during 4-year follow-up periods in non-diabetic hypertensive Korean patients.

Materials and methods

Finally, a total of 1221 consecutive hypertensive patients without a history of diabetes mellitus who had been prescribed CCB were retrospectively enrolled and divided into the two groups, an ACEI group (combination CCB with ACEI, n = 251) and an ARB group (combination CCB with ARB, n = 970). The primary endpoint was NODM, defined as a fasting blood glucose ≥126 mg/dL or hemoglobin A1c ≥ 6.5%. Secondary endpoint was major adverse cardiac events (MACE) defined as total death, non-fatal myocardial infarction (MI) and percutaneous coronary intervention (PCI).

Results

After propensity-score matched (PSM) analysis, two propensity-matched groups (243 pairs, n = 486, C-statistic = 0.696) were generated. During 4-year follow-up periods, there were similar incidence of NODM (Hazard ratio [HR]; 1.198, 95% confidence interval [CI]; 0.591-2.431, P = 0.616), MACE (HR; 1.324, 95% CI; 0.714-2.453, P = 0.373), total death, MI and PCI between the two groups after PSM analysis.

Conclusion

CCB with ACE or CCB with ARB combination strategies are equally acceptable in hypertensive Korean patients regarding the occurrence of NODM.

ST segment elevation in an adult chest pain patient: A case of coronary artery vasospasm

Chest pain is one of the most common symptoms of patients presenting to the emergency department (ED) in the United States, accounting for up to eight million cases annually. We present a 55-year-old male who was brought in to the ED with sudden onset chest pain and was found to have ST-segment elevations in the infero-lateral leads on electrocardiogram (ECG). These changes resolved with nitroglycerin. Coronary artery vasospasm was diagnosed as coronary angiogram was normal. Calcium channel blocker was prescribed with good symptom relief. The most important teaching point is, coronary vasospasm as a cause of ST-segment elevation is missed frequently and should be considered among the differentials in patients presenting with chest pain. Nitrates and/or calcium channel blockers along with avoidance of triggers can help in symptom management.

Antiepileptic effects of cobalt, manganese and magnesium on bicuculline-induced epileptiform activity in hippocampal neurons

BACKGROUND

Calcium signaling is described as a relevant factor in synchronization of neurons and increased excitability in epileptogenesis. Aim of the present investigations was to test the antiepileptic effect of the classical inorganic calcium channel blockers cobalt (Co²⁺), manganese (Mn²⁺) and magnesium (Mg²⁺).

METHODS

Experiments were carried out on hippocampal slices of guinea pigs. Epileptiform field potentials (EFP) were elicited by adding bicuculline (10 µmol/l) to the artificial cerebrospinal fluid (CSF). Kalium was elevated from normal (4 mmol/l) to 8 mmol/l. Co²⁺ (CoCl₂; 2, 1, 0.5 and 0.1 mmol/l), Mn²⁺ (MnCl₂; 2, 1, 0.5 and 0.1 mmol/l) and Mg²⁺ (MgCl₂; 8, 6, 5, 4 and 2 mmol/l) were added to the superfusate.

RESULTS

Concentrations of 2, 1 and 0.5 mmol/l Co²⁺, 2 and 1 mmol/l Mn²⁺ and 8 respectively 6 mmol/l Mg²⁺ were able to suppress EFP sufficient in a dose dependent manner. In concentrations of 0.1 mmol/l Co²⁺, 0.5 mmol/l and 0.1 mmol/l Mn²⁺ and 5 respectively 4 and 2 mmol/l Mg²⁺ suppression was incomplete. With washout of the inorganic calcium channel blockers the EFP reappeared.

DISCUSSION

All tree inorganic calcium channel blockers were able to suppress EFP in a dosage dependent and reversible manner. Weak reappearance of EFP after washout of Co²⁺ might be due to additional cytotoxic effects. The following mechanisms may contribute: i) blockade of voltage-activated calcium channels in the postsynaptic membrane, ii) changes in the activation of voltage-dependent sodium channels, iii) blockade of synaptic transmission.

Effect of U-92032, T-Type Ca2+ Channel Blocker, on Rats with Genetic Absence Epilepsy

INTRODUCTION

Absence epilepsy is associated with diffuse spike-and-wave discharges (SWD) on the electroencephalogram (EEG). Recent studies have demonstrated that the primary somatosensory cortex is also implicated in the generation of the SWDs.

OBJECTIVE

This study investigated the effects of systemic and local administrations of U-92032 into the brain of Genetic Absence Epilepsy Rats from Strasbourg (GAERS).

METHODS

GAERS animals underwent stereotaxic surgery for the placement of EEG recording electrodes and guide cannulas for U-92032 administration into the lateral ventricle (intracerebroventricular [i.c.v.]), upper lips area (S1Ulp) or barrel field area (S1B) of primary somatosensory cortex. Following 7 days of recovery, electrical activity was recorded continuously for 1 h before and 6 h after intraperitoneal (0.25; 1; 5 mg/kg i.p.) or local U-92032 or dimethyl sulfoxide (DMSO) injections.

RESULTS

No changes were detected in the cumulative duration, mean duration, and number of SWDs following i.p. U-92032 injections. Local i.c.v. injections of U-92032 caused a significant decrease in the cumulative duration (i.c.v., 50 and 100 nmol/L), mean duration (i.c.v., 50, 100, and 250 nmol/L), and the number (i.c.v., 250 nmol/L) of SWDs compared to DMSO groups. Intra-cortical (S1Ulp and S1B) U-92032 injections caused a significant decrease in all 3 parameters compared to DMSO groups, as well.

CONCLUSION

Intra-cortical injection of U-92032 caused almost complete removal of SWDs in GAERS and i.c.v. administration resulted in a significant reduction. However, systemic i.p. administration did not cause a significant change with the applied -doses.

To call or not to call: behavioral determinants influencing the decision of intensivists to consult poison centers for calcium channel blocker poisoning

Purpose: This study aimed to define the behavioral determinants influencing the decision of intensivists to consult a poison center (PC) when managing patients with calcium channel blocker (CCB) poisoning.Material and methods: Semi-structured interviews were conducted involving a convenience sample of 18 intensivists. Two independent reviewers analyzed the interview responses using the Theoretical Domains Framework. Based on the impact and frequency of the reported behaviors, we selected the most relevant domains likely to influence intensivists' decision to consult a PC for CCB poisoning.Results: Beliefs influencing physicians positively to consult a PC for CCB poisoning were identified in the following domains: knowledge (e.g., lower level of evidence), social or professional role and identity (e.g., high credibility attributed to the PC), reinforcement (e.g., multiple drug poisoning, infrequent or potentially lethal poisoning, medicolegal considerations), and behavioral regulation (e.g., facilitated access of PC to patient's hospital chart, direct communication with a toxicologist). Beliefs deterring physicians from consulting a PC for CCB poisoning were identified in the following domains: knowledge (e.g., better awareness of recommendations decreases tendency to call), goals (e.g., priority for patient stabilization), and memory, attention, and decision process (e.g., cognitive overload due to an unstable patient).Conclusion: This qualitative study identified potential behavioral targets that future implementation strategies should address to improve collaboration between PCs and intensivists. In light of our results, the Québec PC now asks clinicians if the poisoned patient is unstable prior to collecting any other information. When necessary, a teleconference with the toxicologist is proposed earlier than before.

Risk factor analysis of the decrease in gait speed among Japanese older outpatients with polypharmacy

Background

Both polypharmacy and frailty are critical issues faced by the elderly. The decrease in gait speed is an index of frailty, and it is generally associated with falls and fractures, which are risk factors requiring the need for support or long-term patient care. In this study, we assess the risk factors responsible for the decrease in gait speed in older outpatients with polypharmacy.

Methods

Thirty-one persons (13 men, 18 women) aged 65 years or above and regularly taking 5 or more internal medications participated in this study.

Results

Propensity score-adjusted multivariate logistic analysis showed that only number of medications was associated with the risk of decreasing gait speed (odds ratio: 16.00, 95% confidence interval:1.72–149.00, p value = 0.0149). A negative correlation was found between the number of medications and gait speed. In addition, the gait speed of the calcium channel blocker medication group was significantly slower than that of the non-medication group.

Conclusion

These results suggest that not only the number of medications but also the prescription contents is a risk factor for decrease in gait speed and may serve as indexes to identify patients at high risk of requiring support or long-term care.

Cinnarizine and sodium valproate as the preventive agents of pediatric migraine: A randomized double-blind placebo-controlled trial

BACKGROUND

Few migraine preventive agents have been assessed in a pediatric population. We evaluated the safety and efficacy of cinnarizine and sodium valproate for migraine prophylaxis in children and adolescents.

METHODS

We carried out a randomized double-blind placebo-controlled trial in the Children's Medical Center and Sina hospital, Tehran, Iran. Eligible participants were randomly assigned in 1:1:1 ratio via interactive web response system to receive either cinnarizine, sodium valproate, or placebo. The primary endpoints were the mean change in frequency and intensity of migraine attacks from baseline to the last 4 weeks of trial. The secondary endpoint was the efficacy of each drug in the prevention of migraine. The drug was considered effective if it decreased migraine frequency by more than 50% in the double-blind phase compared with the baseline. Safety endpoint was adverse effects that were reported by children or their parents.

RESULTS

A total of 158 children participated. The frequency of migraine attacks significantly reduced compared to baseline in cinnarizine (difference: -8.0; 95% confidence interval (CI): -9.3 to -6.6), sodium valproate (difference: -8.3; 95% confidence interval: -9.3 to -7.2), and placebo (difference: -4.4; 95% confidence interval: -5.4 to -3.4) arms. The decrease was statistically greater in cinnarizine (difference: -3.6; 95% confidence interval: -5.5 to -1.6) and sodium valproate (difference: -3.9; 95% confidence interval: -5.8 to -1.9) arms, compared to placebo group. Children in all groups had significant reduction in intensity of episodes compared to baseline (cinnarizine: -4.6; 95% confidence interval: -5.2 to -4.0; sodium valproate: -4.0; 95% confidence interval: -4.8 to -3.3; placebo: -2.6; 95% confidence interval: -3.4 to -1.8). The decrease was statistically greater in cinnarizine (difference: -2.0; 95% confidence interval: -3.2 to -0.8) and sodium valproate (difference: -1.5; 95% confidence interval: -2.7 to -0.3) arms, compared to the placebo group. Seventy-one percent of individuals in the cinnarizine group, 66% of cases in the sodium valproate group, and 42% of people in the placebo arm reported more than 50% reduction in episodes at the end of the trial. The odds ratio for >50% responder rate was 3.5 (98.3% confidence interval: 1.3 to 9.3) for cinnarizine versus placebo and 2.7 (98.3% confidence interval: 1.0 to 6.9) for sodium valproate versus placebo. Nine individuals reported adverse effects (three in cinnarizine, five in sodium valproate, and one in the placebo group) and one case in the sodium valproate group discontinued the therapy due to severe sedation.

CONCLUSION

Cinnarizine and sodium valproate could be useful in migraine prophylaxis in children and adolescents. Trial registration: IRCT201206306907N4.

Discovery of Michael acceptor containing 1,4-dihydropyridines as first covalent inhibitors of L-/T-type calcium channels

1,4-Dihydropyridines (DHPs) are an important class of blockers targeting different calcium channel subtypes and have great therapeutic value against cardiovascular and neurophysiologic conditions. Here, we present the design of DHP-based hexahydroquinoline derivatives as either selective or covalent inhibitors of calcium channels. These compounds were synthesized via a modified Hantzsch reaction under microwave irradiation and characterized by IR, ¹H NMR, ¹³C NMR and mass spectra. Additionally, the proposed structure of HM12 was resolved by single crystal X-ray analysis. The abilities of the target compounds to block both L- and T-type calcium channels were evaluated by utilizing the whole-cell patch clamp technique. Our results identified covalent inhibitors of calcium channels for the first time, which could be achieved by introducing a Michael acceptor group into the ester side chain of the compounds. The proposed covalent binding between the compounds and the cysteine amino acid (Cys1492) within the DHP binding pocket of L-type calcium channel was supported by docking and pharmacophore analysis as well as a glutathione reactivity assay.

Treatment of Hypertensive and Hypercholesterolaemic Patients with the Triple Fixed Combination of Atorvastatin, Perindopril and Amlodipine: The Results of the CORAL Study

INTRODUCTION

Hypertension and hypercholesterolaemia are important contributors to the development and progression of atherosclerosis. The coexistence of these two conditions is rather common: hypercholesterolaemia is present in 40-60% of hypertensive patients. Remarkably, patient compliance with antihypertensive regimens is better than with statin therapy. Thus, the inclusion of statins and blood pressure-lowering agents into a fixed combination might even double the effectiveness of statin therapy, and thereby achieve significantly greater reduction of cardiovascular risk. The CORAL study was a 3-month, prospective, multicentre, observational, non-interventional survey, which evaluated the blood pressure- and lipid-lowering efficacy of the triple fixed combination of atorvastatin/perindopril/amlodipine, administered in various dose combinations.

METHODS

The efficacy of the triple fixed combination was reflected by the changes of the blood pressure readings taken in the office and during 24-h blood pressure monitoring (3 months elapsed between visits 1 and 3). The laboratory parameters obtained during data acquisition were also recorded.

RESULTS

After 3 months of therapy, mean office blood pressure decreased from 158.5 ± 16.7/91.7 ± 9.4 to 132.2 ± 8.3/80.1 ± 6.8 mmHg (p < 0.0001), whereas mean 24-h blood pressure decreased from 146.0 ± 14.5/82.5 ± 12.1 to 132.1 ± 13.2/75.6 ± 9.9 mmHg. With regard to metabolic parameters, the inclusion of pre-existing statin therapy in the fixed combination led to further, significant reduction of lipid parameters as follows: total cholesterol level from 6.18 ± 1.15 to 5.16 ± 0.88 mmol/L, LDL-cholesterol from 3.41 ± 1.01 to 2.80 ± 0.82 mmol/L and triglyceride level from 2.26 ± 1.17 to 1.82 ± 0.83 mmol/L (all p < 0.0001).

CONCLUSION

Treatment with the fixed triple combination of atorvastatin, perindopril and amlodipine might take us closer to the optimal therapy for hypertensive patients with hypercholesterolaemia. The expected improvement of patient adherence to treatment may result in an increase of the percentage patients who achieve both blood pressure control and the LDL-cholesterol targets recommended in guidelines. Moreover, this may translate into the further decline of the risk of prospective cardiovascular events.

FUNDING

Egis Pharmaceuticals.

Calcium channel blocker monotherapy versus combination with renin-angiotensin system inhibitors on the development of new-onset diabetes mellitus in hypertensive Korean patients

BACKGROUND

In real practice, two or more antihypertensive drugs are needed to achieve target blood pressure. We investigated the comparative beneficial actions of combination therapy of renin-angiotensin system inhibitors (RASI), with calcium channel blockers (CCB) over CCB monotherapy on the development of new-onset diabetes mellitus (NODM) in Korean patients during four-year follow-up periods.

METHODS

A total of 3208 consecutive hypertensive patients without a history of diabetes mellitus who had been prescribed CCB were retrospectively enrolled from January 2004 to December 2012. These patients were divided into the two groups according to the additional use of RASI (the RASI group, n = 1221 and the no RASI group, n = 1987). Primary endpoint was NODM, defined as a fasting blood glucose ≥ 126 mg/dL or hemoglobin A1c ≥ 6.5%. Secondary endpoint was major adverse cardiac events (MACE) defined as total death, myocardial infarction (MI) and percutaneous coronary intervention (PCI).

RESULTS

After propensity score-matched (PSM) analysis, two propensity-matched groups (939 pairs, n = 1878, C-statistic = 0.743) were generated. The incidences of NODM (HR = 1.009, 95% CI: 0.700-1.452, P = 0.962), MACE (HR = 0.877, 95% CI: 0.544-1.413, P = 0.589), total death, MI, PCI were similar between the two groups after PSM during four years.

CONCLUSIONS

The use of RASI in addition to CCB showed comparable incidences of NODM and MACE compared to CCB monotherapy in non-diabetic hypertensive Korean patients during four-year follow-up period. However, large-scaled randomized controlled clinical trials will be required for a more definitive conclusion.

Calcium Channel Blockers Possibly Delay the Elimination of Plasma Methotrexate in Patients Receiving High-Dose Methotrexate Therapy

Delayed elimination of plasma methotrexate (MTX), which leads to elevated toxicity, is often observed in patients receiving high-dose methotrexate (HD-MTX) therapy, despite of the preventive measures. In this study, we investigated the factors that delay elimination of plasma MTX in patients on HD-MTX therapy. Fifteen patients who received HD-MTX therapy (21 cycles) were classified into two groups: delayed elimination of plasma MTX (38.1%, 8/21) and normal elimination of plasma MTX (61.9%, 13/21). Patient characteristics, plasma MTX concentrations, laboratory values, and adverse reactions were compared between the two groups using Fisher's exact test. Univariate analysis showed that co-administration of calcium channel blockers was significantly associated with delayed elimination of plasma MTX (p = 0.042). This is the first report demonstrating that co-administration of calcium channel blockers may be a predictive factor of delayed elimination of plasma MTX in patients receiving HD-MTX therapy.

Amlodipine-induced gingival enlargement: A case report

Gingival enlargements (GEs) can be caused by local, systemic diseases or drugs. Three molecules can be responsible of GEs: ciclosporin, phenytoin and calcium channel blockers (CCBs). We report the case of a 56-year-old male treated by Amlodipine, a CCB, for hypertension for many years and who recently developed a severe GE affecting both mandibular and maxillary arches inducing dental malposition. The histological examination showed non-specific inflammation with a predominance of lymphocytes. Amlodipine was suspected and suspended in agreement with his physician. One month later, the enlargement significantly reduced but GE was so severe and dental malposition so marked that all the teeth but the canines were extracted. No recurrence was noted one year later. This exceptional case should encourage every practitioner to be vigilant with patient treated with CCBs and their potential side effects and consequences.

Effect of Switching to Azilsartan From Fixed-Dose Combination of an Angiotensin II Receptor Blocker and Calcium Channel Blocker or a Thiazide in Patients With Hypertension

Background

Despite the availability of antihypertensive treatments, fewer than half of patients who receive treatment successfully achieve blood pressure (BP) goals. The purpose of this study was to evaluate the effect of switching to azilsartan 40 mg from a fixed-dose combination tablet of an angiotensin II receptor blocker (ARB) and amlodipine at 5 mg or azelnidipine at 16 mg (ARB/CCB) or an ARB and hydrochlorothiazide (HCT) at 6.25 mg or 12.5 mg (ARB/HCT) on BP.

Methods

This prospective, multicenter, open-labeled, single-arm study included 40 patients treated with a fixed-dose combination tablet of an ARB/CCB or an ARB/HCT, which was switched to azilsartan 40 mg after enrollment. The primary outcome was the change in BP from baseline to the 24-week follow-up.

Results

Of the 40 patients who completed this study, 33 did not require changes in their antihypertensive medications after switching to azilsartan, and their BP did not change from baseline to follow-up. However, the systolic BP in seven patients was elevated at 12 weeks, and amlodipine at 5 mg was therefore added; these patients’ baseline medications were an ARB/CCB (n = 6) and an ARB/HCT (n = 1). In all patients, the serum potassium level was slightly increased after switching to azilsartan at 6 months, while the serum creatinine, hemoblobinA1c, and lipid profile did not change.

Conclusions

Azilsartan at 40 mg did not result in a greater decrease in BP than a fixed-dose combination tablet of an ARB/CCB or an ARB/HCT. However, our findings suggest a substantial BP-lowering effect of azilsartan at 40 mg in patients with hypertension.

Intravenous sustained-release nifedipine ameliorates nonalcoholic fatty liver disease by restoring autophagic clearance

Obesity and overweight, the most serious health problems, are associated with chronic metabolic complications such as type 2 diabetes, insulin resistance, and nonalcoholic fatty liver disease (NAFLD). However, current pharmacological therapies for obesity are challenged by potential side effects, low effectiveness, and low aqueous solubility, which limit their clinical application. Here, we develop nifedipine-loaded nanoparticles (NFD-NPs) that alleviate obesity-related metabolic dysfunction to be used as instruments for translational medicine. Nanoparticles (NPs) composed of poly (lactic-co-glycolic acid) (PLGA) not only enhance water solubility of hydrophobic nifedipine (NFD), a calcium channel blocker, without modifying the chemical structure of NFD for intravenous administration, but also allow prolonged release of NFD in vivo. NFD-NPs do not show cytotoxicity and reduce palmitate-induced protein inclusions and endoplasmic reticulum stress in human hepatoma HepG2 cells. Importantly, tail-vein injection of NFD-NPs into diet-induced obese mice results in sustained retention of NFD-NPs in the liver and suppression of metabolic derangements associated with NAFLD by enhancing autophagic clearance through Ca2+/calmodulin-dependent kinase II (CaMKII) phosphorylation, consequently decreasing diet-induced insulin resistance and improving glucose tolerance. Our findings offer new clinical tools for NP-mediated pharmaceutical strategies to treat NAFLD and its related metabolic dysfunction.

Relationship Between Patterns in Antihypertensive Drugs Medication and Mortality in Incident Dialysis Patients: A Multicenter Prospective Cohort Study

Hypertension is common in patients with chronic kidney disease. Whether blood pressure management before dialysis initiation influences prognosis during maintenance dialysis remains unclear. Hence, we surveyed the status of antihypertensive drug use in incident dialysis patients. Moreover, we examined the association between antihypertensive drug use patterns at the time of dialysis initiation and mortality. We used a database derived from the multicenter prospective Aichi Cohort Study of Prognosis in Patients Newly Initiated into Dialysis, which included 1520 incident dialysis patients in Aichi prefecture, Japan. The baseline in the present study was set as the time of dialysis initiation. We examined antihypertensive drug prescription patterns at baseline, as well as the association between use of antihypertensive drugs and mortality after dialysis initiation. Among all participants, 1440 were taking at least one antihypertensive drug. The rate of calcium channel blocker (CCB) use was highest, accounting for 74.3%. CCB use was significantly associated with lower all-cause and cardiovascular-related mortality (hazard ratio [HR]: 0.62 and 0.57, 95% confidence interval [CI]: 0.46-0.85 and [0.35-0.91], respectively). Compared with no use of either drug, combination therapy with a renin angiotensin system blocker (RASB) and CCB was significantly associated with lower mortality (HR: 0.51, 95% CI: 0.34-0.76). The present study demonstrated that antihypertensive drugs were used in 95% of incident dialysis patients. In addition, use of a CCB and combination therapy with a CCB and RASB at the time of dialysis initiation was associated with lower mortality during maintenance dialysis.

Vascular mechanisms underlying the hypotensive effect of Rumex acetosa

CONTEXT

Rumex acetosa L. (Polygonaceae) is well known in traditional medicine for its therapeutic efficacy as an antihypertensive.

OBJECTIVE

The study investigates antihypertensive potential of crude methanol extract (Ra.Cr) and fractions of Rumex acetosa in normotensive and hypertensive rat models and probes the underlying vascular mechanisms.

MATERIALS AND METHODS

Ra.Cr and its fractions were tested in vivo on normotensive and hypertensive Sprague-Dawley rats under anaesthesia for blood pressure lowering effect. In vitro experiments on rat and Oryctolagus cuniculus rabbit aortae were employed to probe the underlying vasorelaxant mechanism.

RESULTS

In normotensive rats under anaesthesia, Ra.Cr caused fall in MAP (40 mmHg) at 50 mg/kg with % fall of 27.88 ± 4.55. Among the fractions tested, aqueous fraction was more potent at the dose of 50 mg/kg with % fall of 45.63 ± 2.84. In hypertensive rats under similar conditions, extract and fractions showed antihypertensive effect at same doses while aqueous fraction being more potent, exhibited 68.53 ± 4.45% fall in MAP (70 mmHg). In isolated rat aortic rings precontracted with phenylephrine (PE), Ra.Cr and fractions induced endothelium-dependent vasorelaxation, which was partially blocked in presence of l-NAME, indomethacin and atropine. In isolated rabbit aortic rings pre-contracted with PE and K⁺-(80 mM), Ra.Cr induced vasorelaxation and shifted Ca²⁺ concentration-response curves to the right and suppressed PE peak formation, similar to verapamil, in Ca²⁺-free medium.

DISCUSSION AND CONCLUSIONS

The data indicate that l-NAME and atropine-sensitive endothelial-derived NO and COX enzyme inhibitors and Ca²⁺ entry blocking-mediated vasodilator effect of the extract explain its antihypertensive potential.

Lifestyle Modification and Medical Management of Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy is a heterogenous condition associated with a myriad of symptoms. Just as in other disease states, the aim of medical therapy is the alleviation of suffering, improvement of longevity, and the prevention of complications. This article focuses on the associated comorbidities seen in patients with hypertrophic cardiomyopathy, potential lifestyle interventions, and conventional medical treatments for symptomatic hypertrophic cardiomyopathy.

Randomized trial of an increased dose of calcium channel blocker or angiotensin II type 1 receptor blocker as an add-on intensive depressor therapy in type 2 diabetes mellitus patients with uncontrolled essential hypertension: the ACADEMIE Study

There is a lack of data on how to treat hypertensive patients with diabetes when treatment with medium doses of calcium channel blocker and angiotensin II type 1 receptor blocker (ARB) is insufficient to achieve the target blood pressure (BP). A total of 121 participants with type 2 diabetes and uncontrolled essential hypertension, who were receiving medium doses of amlodipine (5 mg/day) and ARB, were enrolled. Participants were randomized to receive either a high dose of amlodipine (10 mg/day) plus a medium dose of ARB (high-AML) or a medium dose of amlodipine (5 mg/day) plus a high dose of ARB (high-ARB). The depressor effects of these two regimens were monitored using a telemonitoring home BP-measuring system. Fifty-four patients were excluded after an observation period, and the remaining 67 eligible participants were randomized into the two groups; 42 which had a record of their home BP for analysis. The change in morning home systolic and diastolic BP was greater in the high-AML than in the high-ARB (systolic BP; - 7.9 mmHg vs. + 2.7 mmHg; p = 0.0002, diastolic BP; - 3.9 mmHg vs. + 0.6 mmHg; p = 0.0007). In addition, the home systolic and diastolic BP before going to bed and office systolic BP were significantly reduced from week 0 only in the high-AML. An increased dose of amlodipine, but not ARB, reduced home morning BP in hypertensive patients with type 2 diabetes who were already receiving combination therapy with medium doses of amlodipine and ARB.

An Update on Calcium Channel Blocker Toxicity in Dogs and Cats

The widespread use and availability of calcium channel blockers in human and veterinary medicine pose a risk for inadvertent pet exposure to these medications. Clinical signs of toxicosis can be delayed by many hours after exposure, with lethargy, hypotension, and cardiac rhythm changes as the predominant signs. Prompt decontamination and aggressive treatment using a variety of modalities may be necessary to treat patients exposed to calcium channel blockers. The prognosis of an exposed patient depends on the dose of the ingested calcium channel blockers, promptness of decontamination and other treatment measures, severity of clinical signs, and response to treatment.

Effect of Anti-Hypertensive Medication History on Arteriovenous Fistula Maturation Outcomes

BACKGROUND

The arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis. However, approximately half of AVFs fail to mature. The use of angiotensin converting enzyme inhibitors (ACE-Is), angiotensin receptor blockers (ARBs), and calcium channel blockers (CCBs) exerts favorable endothelial effects and may promote AVF maturation. We tested associations of ACE-I and ARBs, CCBs, beta-blockers, and diuretics with the maturation of newly created AVFs.

METHODS

We evaluated 602 participants from the Hemodialysis Fistula Maturation Study, a multi-center, prospective cohort study of AVF maturation. We ascertained the use of each medication class within 45 days of AVF creation surgery. We defined maturation outcomes by clinical use within 9 months of surgery or 4 weeks of initiating hemodialysis.

RESULTS

Unassisted AVF maturation failure without intervention occurred in 54.0% of participants, and overall AVF maturation failure (with or without intervention) occurred in 30.1%. After covariate adjustment, CCB use was associated with a 25% lower risk of overall AVF maturation failure (95% CI 3%-41% lower) but a non-significant 10% lower risk of unassisted maturation failure (95% CI 23% lower to 5% higher). ACE-I/ARB, beta-blocker, and diuretic use was not significantly associated with AVF maturation outcomes. None of the antihypertensive medication classes were associated with changes in AVF diameter or blood flow over 6 weeks following surgery.

CONCLUSIONS

CCB use may be associated with a lower risk of overall AVF maturation failure. Further studies are needed to determine whether CCBs might play a causal role in improving AVF maturation outcomes.

Barriers and Facilitators of Intensivists' Adherence to Hyperinsulinemia-Euglycemia Therapy in the Treatment of Calcium Channel Blocker Poisoning

INTRODUCTION

Adherence to poison center (PC) recommendations for the management of calcium channel blocker (CCB) poisoning is inconsistent. This study aimed to identify behaviors that determine adherence to hyperinsulinemia-euglycemia therapy (HIET) for CCB poisoning.

METHODS

Semistructured interviews were conducted involving a convenience sample of 18 intensivists. Interview responses were analyzed using the theoretical domains framework (TDF) to identify relevant domains influencing physician adherence to HIET. Two independent reviewers performed qualitative content analysis of the interview transcripts to identify beliefs influencing decisions to initiate HIET. Initially, beliefs were classified and frequencies reported as being likely to facilitate, likely to decrease, or unlikely to affect adherence. Subsequently, beliefs were linked to a domain within the TDF. Based on the potential impact on physician behavior and frequency of reported behavior, we selected the most relevant domains likely to influence physician adherence to HIET for CCB poisoning.

RESULTS

Positive beliefs were identified in the following domains: "behavioral regulation" (e.g., algorithm for adjustment of perfusions), "belief about capabilities" (e.g., confidence about being able to manage HIET), "belief about consequences" (e.g., fear of clinical deterioration), and "reinforcement" (e.g., clinical instability). Negative beliefs were identified in the following domains as "nature of behavior" (e.g., preference for vasopressors over HIET) and "environmental context and resources" (e.g., accessing dextrose 50% and increased nurse workload).

CONCLUSION

This qualitative study identified potential behavioral targets for future implementation strategies to address to improve adherence to HIET.