Perioperative coronary artery spasm after off-pump coronary artery bypass grafting in the non-manipulated coronary artery

BACKGROUND

Perioperative coronary artery spasm (CAS) following coronary artery bypass grafting (CABG) is a severe or lethal condition that is rarely reported. In addition, rare cases with CAS following CABG in the non-manipulated coronary artery are angiographically documented in the perioperative period. We aimed to report our experiences on the diagnosis and treatment of a case with CAS following off-pump CABG in the non-manipulated coronary artery.

METHODS

A 57-year old male with coronary heart disease and unstable angina willing to undergo CABG was admitted to our department. CABG was recommended as he showed 90% stenosis in distal left anterior descending artery, 90% stenosis in intermediate branch, 90% stenosis in left circumflex coronary artery, as well as 50% stenosis in proximal right coronary artery (RCA).

RESULTS

After CABG, the patient showed Adams-Stokes syndrome and ST-segment elevation. Then CPR was conducted and coronary angiography indicated perioperative CAS in the non-manipulated posterior descending artery. For the treatment, the patient received nitroglycerin injection into the coronary artery by catheter and pumping of diltiazem. Finally, the patient was discharged on day 7 after surgery. A comprehensive literature search was conducted to summarize the studies focused on the diagnosis and treatment of such condition, which indicated that all of the CAS cases occurred in the manipulated vessels, except one study showing CAS in the untouched native coronary artery which was similar with our case.

CONCLUSIONS

Perioperative CAS in the non-manipulated coronary artery following CABG is a severe or lethal condition that is rarely reported, which deserves close attention by the clinicians in clinical practice.

Visualization of calcium channel blockers in human adrenal tissues and their possible effects on steroidogenesis in the patients with primary aldosteronism (PA)

Voltage-gated L-type calcium channel (CaV) isoforms are well known to play pivotal tissue-specific roles not only in vasoconstriction but also in adrenocortical steroidogenesis including aldosterone biosynthesis. Alpha-1C subunit calcium channel (CC) (CaV1.2) is the specific target of anti-hypertensive CC blockers (CCBs) and its Alpha-1D subunit (CaV1.3) regulates depolarization of cell membrane in aldosterone-producing cells. Direct effects of CCBs on aldosterone biosynthesis were previously postulated but their intra-adrenal distribution and effects on steroid production in primary aldosteronism (PA) patients have remained virtually unknown. In this study, frozen tissue specimens constituting tumor, adjacent adrenal gland and peri-adrenal adipose tissues of nine aldosterone-producing adenoma (APA) cases were examined for visualization of amlodipine and aldosterone themselves using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). Liquid chromatography-mass spectrometry (LC-MS) analysis was also performed to quantify amlodipine and 17 adrenal steroids in those cases above and compared the findings with immunohistochemical analysis of steroidogenic enzymes and calcium channels (CaV1.2 and CaV1.3). Effects of amlodipine on mRNA level of aldosterone biosynthetic enzymes were also explored using human adrenocortical carcinoma cell line (H295R). Amlodipine-specific peak (m/z 407.1 > 318.1) was detected only in amlodipine treated cases. Accumulation of amlodipine was marked in adrenal cortex compared to peri-adrenal adipose tissues but not significantly different between APA tumors and adjacent adrenal glands, which was subsequently confirmed by LC-MS quantification. Intra-adrenal distribution of amlodipine was generally consistent with that of CCs. In addition, quantitative steroid profiles using LC-MS and in vitro study demonstrated the lower HSD3B activities in amlodipine treated cases. Immunoreactivity of CaV1.2 and HSD3B2 were also correlated. We report the first demonstration of specific visualization of amlodipine in human adrenal tissues by MALDI-MSI. Marked amlodipine accumulation in the adrenal glands suggested its direct effects on steroidogenesis in PA patients, possibly targeting on CaV1.2 and suppressing HSD3B activity.

Association between dihydropyridine calcium channel blockers and ischemic strokes in patients with nonvalvular atrial fibrillation

Outside of clinical trials, the prophylactic effect of dihydropyridine calcium channel blockers (CCBs) on ischemic events in patients with nonvalvular atrial fibrillation (NVAF) has not been confirmed. We compared the effect of dihydropyridine CCBs on ischemic events in anticoagulated NVAF patients. We conducted a multicenter historical cohort study at 71 centers in Japan. The inclusion criterion was taking vitamin K antagonists for NVAF. The exclusion criteria were mechanical heart valves and a history of pulmonary thrombosis or deep vein thrombosis. Consecutive patients (N = 7826) were registered in February 2013 and were followed until February 2017. The primary outcomes were ischemic events and ischemic strokes; the secondary outcomes were all-cause mortality, major bleeding, and hemorrhagic strokes. The mean patient age was 73 years old, and 67% of the patients were male. Seventy-eight percent of the patients had hypertension, and dihydropyridine CCBs were used by 2693 (34%) patients (CCB group). The cumulative incidences of ischemic events and ischemic strokes at 4 years in the CCB and No-CCB groups were 5.9% vs. 5.2% and 5.6% vs. 4.8%, respectively. The adjusted hazard ratios (HRs) (95% confidence intervals [CIs]) of the CCB group for ischemic events and ischemic strokes were 1.22 (0.95-1.57) and 1.32 (1.02-1.71), respectively; the adjusted HRs (95% CIs) of the CCB group for all-cause mortality, major bleeding, and hemorrhagic strokes were 0.85 (0.69-1.04), 1.12 (0.92-1.35), and 1.08 (0.62-1.88), respectively. Dihydropyridine CCB use by anticoagulated NVAF patients significantly increased ischemic strokes in a real-world setting.

Assessing the role of blood pressure in amyotrophic lateral sclerosis: a Mendelian randomization study

BACKGROUND

Observational studies have suggested a close but controversial relationship between blood pressure (BP) and amyotrophic lateral sclerosis (ALS). It remains unclear whether this association is causal. The authors employed a bidirectional two-sample Mendelian randomization (MR) approach to evaluate the causal relationship between BP and ALS. Genetic proxies for systolic blood pressure (SBP), diastolic blood pressure (DBP), antihypertensive drugs (AHDs), ALS, and their corresponding genome-wide association study (GWAS) summary datasets were obtained from the most recent studies with the largest sample sizes. The inverse variance weighted (IVW) method was adopted as the main approach to examine the effect of BP on ALS and four other MR methods were used for sensitivity analyses. To exclude the interference between SBP and DBP, a multivariable MR approach was used.

RESULTS

We found that genetically determined increased DBP was a protective factor for ALS (OR = 0.978, 95% CI 0.960-0.996, P = 0.017) and that increased SBP was an independent risk factor for ALS (OR = 1.014, 95% CI 1.003-1.025, P = 0.015), which is supported by sensitivity analyses. The use of calcium channel blocker (CCB) showed a causal relationship with ALS (OR = 0.985, 95% CI 0.971-1.000, P = 0.049). No evidence was revealed that ALS caused changes in BP.

CONCLUSIONS

This study provides genetic support for a causal effect of BP and ALS that increased DBP has a protective effect on ALS, and increased SBP is a risk factor for ALS, which may be related to sympathetic excitability. Blood pressure management is essential in ALS, and CCB may be a promising candidate.

A systematic review and meta-analysis of the efficacy of topical sphincterotomy treatments for anal fissure

BACKGROUND

Anal fissure is a common condition that can be treated medically or surgically. Chemical sphincterotomy is often used before surgical intervention. This study aims to evaluate the effectiveness of topical agents for chemical sphincterotomy on healing of anal fissures and side-effects.

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) compliant systematic review was performed using MEDLINE, EMBASE, Scopus, and CENTRAL databases. Eligible studies included randomized controlled trials which compared topical sphincterotomy agents with topical placebo agents or each other. Studies that included surgical treatments were excluded. Overall evidence was synthesized according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.

RESULTS

Thirty-seven studies met the study selection criteria. Seventeen studies show that glyceryl trinitrate (GTN) was significantly more likely to heal anal fissure than placebo (relative risk (RR) = 1.96, 95% confidence interval (95%CI) = 1.35-2.84, I2 = 80%). Eleven studies showed a marginally significant difference between healing rates for diltiazem vs GTN, RR = 1.16, (1.01-1.33) I2 = 48%. There was no significant difference in healing between diltiazem and placebo, RR = 1.65, (0.64-4.23), I2 = 92%. GTN significantly reduced pain on the visual analog scale compared to the placebo group, MD-0.97 (-1.64 to -0.29) I2 = 92%. There was high certainty of evidence that GTN was significantly more likely to cause headache than placebo (RR = 2.73 (1.82-4.10) I2 = 58%) and diltiazem RR = 6.88 (2.19-21.63) I2 = 17%.

CONCLUSION

There is low certainty evidence topical nitrates are an effective treatment for anal fissure healing and pain reduction compared to placebo. Despite widespread use of topical diltiazem, more evidence is required to establish the effectiveness of calcium channel blockers compared to placebo.

A case of complete atrioventricular block with extremely high blood concentration of azelnidipine

Background

Azelnidipine, a dihydropyridine calcium channel blocker (CCB), has less adverse effects (e.g. hot flushes and reflex tachycardia) compared to other dihydropyridine CCBs. Azelnidipine has been reported to reduce heart rate as opposed to inducing tachycardia. No evidence of bradycardia or complete atrioventricular block (CAVB) with azelnidipine treatment has been reported.

Case presentation

In the present study, a 92-year-old woman was diagnosed with CAVB while taking azelnidipine and simvastatin for an extended period of time, and referred to our medical center. It was thought that the CAVB may have been an adverse effect of azelnidipine treatment. Specifically, it was considered that in this patient, one of the causes might be the concomitant use of simvastatin inhibiting the metabolism of azelnidipine by cytochrome P450 enzyme 3A4. Consequently, it was suggested to the patient’s physician that the patient’s serum azelnidipine levels be measured and treatment with azelnidipine and simvastatin be discontinued. The patient’s serum concentration of azelnidipine at the time of her visit to our center was 63.4 ng/mL, higher than the normal acceptable level. There was no occurrence of CAVB for 4 weeks, to present, following discontinuation of azelnidipine and simvastatin treatment.

Conclusions

Azelnidipine has a different mechanism of action that other CCBs. In very rare cases, it may cause CAVB when combined with CYP3A4 inhibitors. If a patient taking azelnidipine is diagnosed with CAVB, physicians should suspect that the condition may be an adverse effect of azelnidipine and should consider discontinuing azelnidipine. And, in the elderly, it is necessary to avoid concomitant use of CYP3A4 inhibitors.

FDA approved L-type channel blocker Nifedipine reduces cell death in hypoxic A549 cells through modulation of mitochondrial calcium and superoxide generation

As hypoxia is a major driver for the pathophysiology of COVID-19, it is crucial to characterize the hypoxic response at the cellular and molecular levels. In order to augment drug repurposing with the identification of appropriate molecular targets, investigations on therapeutics preventing hypoxic cell damage is required. In this work, we propose a hypoxia model based on alveolar lung epithelial cells line using chemical inducer, CoCl₂ that can be used for testing calcium channel blockers (CCBs). Since recent studies suggested that CCBs may reduce the infectivity of SARS-Cov-2, we specifically select FDA approved calcium channel blocker, nifedipine for the study. First, we examined hypoxia-induced cell morphology and found a significant increase in cytosolic calcium levels, mitochondrial calcium overload as well as ROS production in hypoxic A549 cells. Secondly, we demonstrate the protective behaviour of nifedipine for cells that are already subjected to hypoxia through measurement of cell viability as well as 4D imaging of cellular morphology and nuclear condensation. Thirdly, we show that the protective effect of nifedipine is achieved through the reduction of cytosolic calcium, mitochondrial calcium, and ROS generation. Overall, we outline a framework for quantitative analysis of mitochondrial calcium and ROS using 3D imaging in laser scanning confocal microscopy and the open-source image analysis platform ImageJ. The proposed pipeline was used to visualize mitochondrial calcium and ROS level in individual cells that provide an understanding of molecular targets. Our findings suggest that the therapeutic value of nifedipine may potentially be evaluated in the context of COVID-19 therapeutic trials.

Calcium channel blocker in patients with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is involved in a progressive deterioration in renal function over the years and is now a global public health problem. Currently, reducing the number of patients progressing to end-stage renal failure is urgently necessary. Hypertension and CKD interact with each other, and good control of blood pressure (BP) can improve CKD patients' prognosis. With the current global trend for more strict BP control, the importance of BP management and the need for medication to achieve this strict goal are increasing. Calcium channel blockers (CCBs), which target voltage-dependent calcium channels, are frequently used in combination with renin-angiotensin-aldosterone system inhibitors for CKD patients because of their strong BP-lowering properties and relatively few adverse side effects. Calcium channels have several subtypes, including L, N, T, P/Q, and R, and three types of CCBs, L-type CCBs, L-/T-type CCBs, and L-/N-type CCBs, that are available. Nowadays, the new functions and effects of the CCBs are being elucidated.

CONCLUSION

We should use different types of CCBs properly depending on their pharmacological effects, such as the strength of antihypertensive effects and the organ protection effects, taking into account the pathophysiology of the patients. In this article, the role and the use of CCBs in CKD patients are reviewed.

Trends in Calcium Channel Blocker Use in Patients with Heart Failure with Reduced Ejection Fraction and Comorbid Atrial Fibrillation

BACKGROUND

Heart failure with reduced ejection fraction and atrial fibrillation commonly coexist. Most calcium channel blockers are not recommended in heart failure with reduced ejection fraction, but their use has been seldom evaluated. For patients with heart failure with reduced ejection fraction and comorbid atrial fibrillation, we sought to 1) determine the proportion discharged on contraindicated calcium channel blockers, 2) describe how clinicians' use of these medications at discharge have changed over time, and 3) identify predictors for contraindicated calcium channel blocker prescription at discharge.

METHODS

We analyzed 395 patients discharged with heart failure with reduced ejection fraction and atrial fibrillation between 2008 and 2018. Discharge on a contraindicated calcium channel blocker (any calcium channel blocker except amlodipine) was the primary outcome. Changes in calcium channel blocker prescription over time were evaluated with a Cochran-Armitage trend test. Multivariable logistic regression was used to identify predictors of calcium channel blocker prescription at discharge.

RESULTS

Twenty-nine (7.3%) patients were discharged on a contraindicated calcium channel blocker without change over time (P_trend = .38). Of these, 26 (86.7%) were discharged on multiple atrioventricular nodal blocking medications. Hypertension (odds ratio [OR] 7.87; 95% confidence interval [CI], 1.04-59.40) and female sex (OR 3.01; 95% CI, 1.36-6.67) were both associated with contraindicated calcium channel blocker prescription at discharge while diabetes mellitus was negatively associated with this outcome (OR 0.34; 95% CI, 0.14-0.88).

CONCLUSION

One in 14 patients with heart failure with reduced ejection fraction and comorbid atrial fibrillation were discharged on a contraindicated calcium channel blocker, without change over time. Most patients were discharged on multiple atrioventricular nodal blockers, highlighting potential need for greater coordination between discharging physicians, pharmacists, and electrophysiology.

Effectiveness and safety assessment of beta-blockers, calcium channel blockers, and angiotensin receptor blockers in hypertensive patients: a prospective study

BACKGROUND

Hypertension is most common prevailing cardiovascular disease worldwide. In this condition the effectiveness and safety of already available and many time-tested medications should be regularly reviewed.

METHODOLOGY

Ethical approval of study was obtained from human research ethics committee of the hospital. 180 patients were enrolled with three groups of antihypertensive medication groups as calcium channel blocker (amlodipine), beta blocker (metoprolol) and angiotensin receptor blocker (telmisartan) over a span of eight months. The data was obtained from week zero to twelve (SBP: Systolic Blood Pressure and DBP: Diastolic Blood Pressure). Safety of Beta blocker, calcium channel blocker and angiotensin receptor blocker were investigated.

RESULTS

Comparison of efficacy between the beta blocker, calcium channel blocker and angiotensin blocker receptor blocker were shown to be non-significant. It indicated that all drug therapies have the same successful reduction of SBP (P-0.4819). No significant adverse reactions were observed in either class of the medicines.

CONCLUSION

The study showed the efficacy of Calcium Channel Blocker, Beta Blocker and Angiotensin Receptor Blocker in reduction of SBP & DBP was same, while Calcium Channel Blockers were superior to other two medications.

Refractory Shock from Amlodipine Overdose Overcomed with Hyperinsulinemia

Intoxication from calcium channel blockers exhibits almost 50% mortality rates. Amlodipine is a long-acting dihydropyridine and inappropriate dosage poses a great threat for profound vasodilation, hypotension, and refractory vasopressor-resistant shock. A 72-year-old woman with unremarkable medical history presented to the emergency department due to amlodipine overdose after a suicide attempt attributed to COVID-19 pandemic severe anxiety disorder. Vital signs at presentation: heart rate 82 beats/ min, arterial pressure 72/55 mmHg, and oxygen saturation 98%. Resuscitation was initiated with intravenous infusion of normal saline 0,9%, noradrenaline, and calcium chloride, while activated charcoal was orally administrated; however, blood pressure remained at 70/45 mmHg. Abruptly, she experienced acute pulmonary edema and was finally intubated. We commenced high-dose insulin infusion with Dextrose 10% infusion to maintain euglycemic hyperinsulinemia. Hemodynamic improvement occurred after 30 min, systolic blood pressure raised to 95 mmHg, and decongestion was achieved with intravenous furosemide. Insulin effect was dose-dependent and patient’s hemodynamic status improved after insulin uptitration. Eight days later, the patient was weaned from the mechanical ventilation and she was successfully discharged after 14 days. High-dose intravenous infusion of insulin up to 10 units/kg per hour appears as an inotropic agent possibly through alterations in myocardial metabolism of fatty acids and augmentation of insulin secretion and uptake. This regimen possibly exhibits additional vasotropic properties. We conclude that euglycemic hyperinsulinemia is a potentially advantageous treatment in CCB toxicity.

Association of calcium channel blocker use with clinical outcome of COVID-19: A meta-analysis

AIMS

This meta-analysis aims to analyze the association of calcium channel blocker (CCB) use with COVID-19 clinical outcomes.

METHODS

PubMed, ProQuest, Science Direct, Scopus, and medRxiv databases were searched systematically in a limited period. The primary outcome was mortality.

RESULTS

A total of 119,298 patients from 31 eligible studies were included. Pooled analysis of the random-effect model revealed CCB was not associated with reduced mortality (OR = 1.21 [95%CI: 0.98-1.49], p = 0.08). Interestingly, subgroup analysis in hypertensive patients revealed significantly reduced mortality (OR = 0.69 [95%CI: 0.52-0.91], p = 0.009).

CONCLUSION

CCB usage was not associated with the outcome of COVID-19. However, CCB was associated with a decreased mortality rate in hypertensive COVID-19 patients.

Cardioprotective, hypotensive and toxicological studies of Populus ciliata (Wall. ex Royle)

Populus ciliata Wall ex. Royle has folkloric repute to treat various cardiovascular ailments and related disorders. The current study was designed to evaluate the toxic profile, cardioprotective and hypotensive effects of Populus ciliata (Wall. ex Royle). Populus ciliata crude ethanolic extract (Pc. Cr) and its aqueous (Pc. Aq) & organic (Pc. Dcm) fractions were tested on isolated aorta of rat and rabbit having intact and non-intact endothelium respectively. Pc. Cr & Pc. Aq relaxed the contractions induced by PE (1 µM)-induced and K⁺ (80 mM)-induced on aorta, possibly by mediating endothelium derived relaxing factor (EDRF) in intact endothelium and voltage dependent L-type calcium channels blocking (CCB) mechanism in non-intact endothelium. Pc. Cr showed anti-hypertensive & cardioprotective activity by decreasing force of contraction & heart rate on isolated rabbit paired atria and reduced blood pressure in anesthetized rat. Cardioprotective effect of Pc. Cr was assessed in isoproterenol induced acute myocardial infarction (AMI) and left ventricular hypertrophy (LVH) in Sprague Dawley rats. In LVH, Pc. Cr exerted positive effects by decreasing angiotensin II & renin and increasing cGMP & nitric oxide (NO) with reduced cardiac fibrosis, necrosis and cardiac cell size. In AMI, Pc. Cr responded effectively by decreasing cardiac markers creatinine kinase (CK), creatinine kinase myocardial band (CK-MB) and lactate dehydrogenase (LD) in blood associated with less edema and necrosis. Presence of catechin, vinallic acid, P-coumeric acid and quercitin identified through HPLC support the effectiveness of Pc. Cr in hypertension, AMI and LVH. Pc. Cr showed no significant adverse effects in Sprague Dawley albino rats after acute & sub-acute treatment in histopathological investigation. Extract of Populus ciliata showed vasorelaxant, hypotensive and cardioprotective effect in Sprague Dawley albino rats and white albino rabbit by mediating EDRF and voltage dependent L-type CCB mechanism respectively.

L-type calcium channel blocker use and proteinuria among children with chronic kidney diseases

BACKGROUND

Hypertension is common among children with chronic kidney disease (CKD), and dihydropyridine calcium channel blockers (dhCCBs) are frequently used as treatment. The impact of dhCCBs on proteinuria in children with CKD is unclear.

METHODS

Data from 722 participants in the Chronic Kidney Disease in Children (CKiD) longitudinal cohort with a median age of 12 years were used to assess the association between dhCCBs and log transformed urine protein/creatinine levels as well as blood pressure control measured at annual visits. Angiotensin-converting enzyme inhibitor (ACEi) and angiotensin receptor blocker (ARB) use was evaluated as an effect measure modifier.

RESULTS

Individuals using dhCCBs had 18.8% higher urine protein/creatinine levels compared to those with no history of dhCCB or ACEi and ARB use. Among individuals using ACEi and ARB therapy concomitantly, dhCCB use was not associated with an increase in proteinuria. Those using dhCCBs had higher systolic and diastolic blood pressures.

CONCLUSIONS

Use of dhCCBs in children with CKD and hypertension is associated with higher levels of proteinuria and was not found to be associated with improved blood pressure control.

Postoperative atrial fibrillation in paraesophageal hernia repair: can it be prevented?

Acute ischemic thromboembolic stroke is one of the most feared complications of atrial fibrillation (AF), and the risk increases with higher CHA2DS2-VASc scores. Postoperative atrial fibrillation (POAF) is common after noncardiac surgery, particularly after thoracic surgery, and can result in significant morbidity and mortality. We report the case of an 85-year-old female with a history of untreated hypertension (HTN) and no prior history of AF, who presented 5 days after an elective repair of a paraesophageal hernia with recurrence of a large type III paraesophageal hiatal hernia, AF, and subsequent acute thromboembolic ischemic stroke. Patient’s AF resolved shortly after treatment with calcium channel blocker. The risk of stroke is high in patients who develop AF and a period of 48 h after onset of AF is usually considered safe as the risk of stroke is low in this time period. However, this may not be the case during the perioperative period and preventive measures such as preoperative calcium channel blocker could be considered. Our case highlights that acute ischemic thromboembolic stroke might develop earlier tha 48 h after onset of POAF in patients undergoing paraesophageal hernia repair. Initiation of a calcium channel blocker should be considered during preoperative evaluation for patients undergoing paraesophageal hernia repairs, especially in those with untreated HTN.

Efonidipine Exerts Cerebroprotective Effect by Down-regulation of TGF-β/SMAD-2-Dependent Signaling Pathway in Diabetic Rats

Calcium overload and hyperglycemia are risks of stroke onset in diabetics. Our study was designed to elucidate the beneficial role of calcium channel blockers by targeting voltage-gated calcium channels in diabetes-associated cerebrovascular complications. Diabetes was induced using the neonatal streptozotocin rat model. After confirmation of diabetes, middle cerebral artery occlusion (MCAO) was carried out. The pre-treatment with 1 mg/kg/day efonidipine was administered for the period of 4 weeks. After 24 h of ischemic induction surgery, the neurological score was determined, and blood was collected for determination of biochemical parameters. Treatment with efonidipine showed a significant reduction in post-ischemic brain infract volume, brain hemisphere weight difference, neurological score, Na⁺-K⁺ ATPase activity, serum CK-MB, and LDH levels in normoglycemic and hyperglycemic MCAO-induced animals. While no significant changes in glucose and lipid levels were observed by treatment, efonidipine significantly decreased the levels of malondialdehyde, acetylcholine esterase, and nitrite levels and increased the levels of antioxidant markers in both normoglycemic and hyperglycemic MCAO animals. TGF-β and VEGF were found to be down-regulated after treatment with efonidipine in gene expression study. In conclusion, the study data supports the cerebroprotective role of efonidipine in diabetic animals possibly through TGF-β/SMAD-2 signaling pathway.

Drug-induced gingival overgrowth in cardiovascular patients

Drug-induced gingival overgrowth (DIGO) is a pathological growth of gingival tissue, primarily associated with calcium channel blockers and immunosuppressants. Consequently, it is mainly seen in cardiovascular and transplanted patients. Nifedipine remains the main calcium channel blocker related to the development of this unpleasant side-effect. As for immunosuppressants, cyclosporin is the leading causative agent, whereas other drugs from this drug-group, including tacrolimus, have better safety profiles. Accumulated collagen with inflammatory infiltrates is the histological hallmark of this condition. Several factors are involved in the pathogenesis and can increase the risk, such as male gender, younger age, pre-existing periodontal inflammation, and concomitant use of other DIGO-inducing medications. Patients with DIGO may experience severe discomfort, trouble with speech and mastication, pain, and teeth loss, aside from cosmetic implications. Furthermore, these patients also have an increased risk for cardiovascular diseases. The interdisciplinary approach and cooperation with dental care experts are necessary for patient management. Treatment includes discontinuing the drug and switching to one with a better profile, improving oral hygiene, and surgical removal of enlarged tissue. Recognizing the potential of commonly used medications to cause DIGO and its effect on patients' health is necessary for early detection and adequate management of this complication.

Hypertension in Kidney Transplant Recipients: Where Are We Today?

PURPOSE OF REVIEW

Cardiovascular disease is the leading cause of death and allograft loss among kidney transplant recipients, and hypertension is an independent risk factor for cardiovascular morbidity of this patient population. The etiology of hypertension is multifactorial, including pre-transplant volume overload, post-transplant recipient and donor-associated variables, and transplant-specific causes (immunosuppressive medications, allograft dysfunction and surgical complications such as transplant artery stenosis).

RECENT FINDINGS

No randomized controlled trials have assessed the optimal blood pressure targets and explored the best antihypertensive regimen for kidney transplant recipients. According to the large observational studies, it is reasonable to achieve a blood pressure goal of equal to or less than 130/80 mmHg in the long-term follow-up for minimizing the cardiovascular morbidity. The selection of antihypertensive agents should be based on the patient's co-morbidities; however, the initial choice could be calcium channel blockers especially in the first few months of transplantation. In patients with cardiovascular indications of renin-angiotensin-aldosterone system inhibition, given the well-described benefits in diabetic and proteinuric patients, it is reasonable to consider the use of renin-angiotensin-aldosterone system inhibitors. There is a need for future prospective trials in the transplant population to define optimal blood pressure goals and therapies.

Identification of novel pregnane X receptor (PXR) agonists by In silico and biological activity analyses and reversal of cigarette smoke-induced PXR downregulation

Cigarette smoke (CS) contains many toxins that collectively harm nearly every organ in the body, and smoking is a key risk factor for many chronic diseases. Aside from its toxic actions, CS may alter expression of the drug- and steroid-binding pregnane X receptor (PXR), which when activated upregulates expression of cytochrome P450 (CYP) enzymes, glutathione transferases (GSTs), and multidrug resistance protein 1 (MDR1), an adaptive metabolic array that mediates clearance of CS component toxins. We sought to identify new PXR agonists that may be useful for restoring PXR activity in conditions wherein it is suppressed, and their mechanisms of PXR binding and activation. PXR has a uniquely larger, hydrophobic, and highly flexible ligand-binding domain (LBD) vs. other nuclear receptors, enabling it to interact with structurally diverse molecules. We tested certain calcium channel blockers (CCBs) as a pharmacological subset of potential PXR ligands, analyzing by molecular docking methods, and identified a putative active site in the PXR LBD, along with the relevant bonds and bonding energies. We analyzed felodipine binding and agonist activity in detail, as it showed the lowest binding energy among CCBs tested. We found felodipine was a potent PXR agonist as measured by luciferase reporter assay, whereas CCBs with higher binding energies were less potent (amlodipine) or nearly inactive (manidipine), and it induced CYP3A4 expression in HepG2 cells, a known target of PXR agonism. Felodipine also both induced PXR mRNA in HepG2 hepatocytes and reduced CS extract-induced diminution of PXR levels, indicating it modulates PXR expression. The results illuminate mechanisms of ligand-induced PXR activation and identify felodipine as a novel PXR agonist.

Calcium Channel blockers are associated with reduced risk of Parkinson's disease in patients with hypertension: A population-based retrospective cohort study

BACKGROUND

The use of dihydropyridine calcium channel blockers (DCCBs) was proposed to reduce the risk of Parkinson's disease (PD). This study aimed to evaluate the association between DCCB and its dose effect and the risk of PD in patients with newly diagnosed hypertension.

METHODS

This population-based retrospective cohort study enrolled 107,207 patients with newly diagnosed hypertension, between 2001 and 2013, from Taiwan's National Health Insurance Research Database. Patients who had PD before hypertension or were taking antipsychotics for more than 30 days in the 6 months prior to the end of the observation period were excluded. A Cox proportional hazard model was used to estimate the risk of PD in different groups. The dose-related effects of DCCB on the risk of PD were evaluated according to the cumulative defined daily dose (DDD).

RESULTS

We observed 832 (1.2%) PD cases in patients treated with DCCB as compared to 950 (2.4%) PD cases in those not treated with DCCB, during a median follow-up duration of 8.3 years and 6.2 years, respectively. The risk of PD in the DCCB-treated group (hazard ratio [HR] = 0.50) was significantly lower than that in the group without DCCB treatment. DCCB reduced the risk of PD in a dose-dependent manner, with HRs ranging from 0.61 to 0.37 for DDDs of 90-180 to >720.

CONCLUSIONS

DCCB treatment was associated with a significantly reduced risk of PD in patients with newly diagnosed hypertension. Further clinical trials are needed to confirm the proposed neuroprotective effects of DCCB in PD.

Effects of intravenous administration of recombinant Phα1β toxin in a mouse model of fibromyalgia

This study investigated the effects of intravenous (iv) administration of recombinant Phα1β toxin, pregabalin, and diclofenac by the intrathecal route using an animal model fibromyalgia (FM). The reserpine administration (0.25 mg/kg s. c) once daily for three consecutive days significantly induced hyperalgesia, immobility time, and sucrose consumption in mice on the 4th day. Reserpine caused hyperalgesia on the mechanical and thermal hyperalgesia on the 4th day was reverted by recombinant Phα1β (0.2 mg/kg iv) and pregabalin (1.25 μmol/site i. t) treatments. In contrast, diclofenac (215 nmol/site i. t) was ineffective. Recombinant Phα1β toxin, pregabalin, and diclofenac did not affect the depressive-like behavioural effect induced by reserpine on mice during the forced swim and sucrose consumption tests. The data confirmed the analgesic effect of the recombinant Phα1β toxin administered intravenously in a fibromyalgia mouse model.

SMART Syndrome Identification and Successful Treatment

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare late complication of brain irradiation. Patients commonly present recurrent attacks of headaches, seizures, and paroxysmal focal neurological deficits including aphasia, negligence, or hemianopsia. We report a 41-year-old male patient admitted to our emergency room with a reduced level of consciousness and global aphasia. One month prior to admission, he started with frequent headache attacks of moderate intensity and paroxysmal behavioral alterations, advancing to confusion, gait instability, language impairment, and somnolence. He had a history of medulloblastoma treated with surgical resection followed by craniospinal irradiation 21 years before symptom onset. After excluding more frequent causes for the patient's symptoms along with a suggestive image pattern, we started treatment for SMART syndrome with high-dose corticosteroid and calcium channel blocker verapamil. The patient gradually improved his level of consciousness and recovered from aphasia and gait instability without new seizures or neuropsychiatric symptoms. Follow-up brain magnetic resonance imaging showed resolution of the typical findings. This case displays a successful clinical evolution of a patient treated for SMART syndrome in which identification of previous radiation treatment, exclusion of other etiologies, and prompt treatment institution were key for effectively tackling this disease.

Bioenergetics impairment of Trypanosoma cruzi by the antihypertensive manidipine: A drug repurposing strategy

Considering the lack of effective and safe therapy for the treatment of Chagas disease, the antihypertensive drug manidipine (MDP) was in vitro evaluated against Trypanosoma cruzi. The bioenergetics of trypomastigotes was studied in the presence of the drug using fluorimetric and luminescent assays. Manidipine showed a potent antiparasitic activity, with IC₅₀ values of 0.1 μM (intracellular amastigotes) and 3 μM (trypomastigotes), resulting in a promising selectivity index against the amastigotes (>1459). Using fluorimetric analysis, the drug showed depolarisation of the electric potential of the plasma membrane with no alteration of the permeability. A decrease in ATP levels suggested a bioenergetic alteration of the mitochondria, which was confirmed by the depolarisation of the mitochondrial membrane potential and a slight increase of the ROS levels. This is the first study to show the promising in vitro effectiveness of the antihypertensive MDP against T. cruzi, which may represent a candidate for future investigations in animal models.

Finger blood flow after the cold challenge with primary Raynaud's syndrome: a case report

Background 

Raynaud’s syndrome is a commonly encountered disorder. The relationship between the grade of Raynaud’s phenomenon and severity of vasoconstriction is unclear. Recently, various methods including colour Doppler ultrasonography have been used for assessment of vascularity of the extremities including fingers.

Case summary 

A 53-year-old man had a 6-year history of Raynaud’s phenomenon with typical tri-coloured changes proceeding from white, blue to red and slight pain and slight paresthaesia in the fingers of both hands when his fingers were exposed to cold. He was diagnosed with primary Raynaud’s syndrome. After treatment with the calcium channel blocker amlodipine (5 mg once daily), a cold challenge did not induce Raynaud’s phenomenon on the fingers in the present patient. After the cold challenge, colour Doppler ultrasonography showed that vascularity was markedly decreased or was absent, whereas there was little difference in skin colour of the fingers.

Discussion 

In Raynaud's phenomenon, vasospasm may occur even if the symptoms are well-controlled with a calcium channel blocker. It is unlikely that clinical symptoms in patients with Raynaud’s syndrome always reflect the severity of vasoconstriction in their fingers.

Rapid reversal of vasoplegia with methylene blue in calcium channel blocker poisoning

INTRODUCTION

Calcium channel blockers (CCBs) are a potent class of medications that exert its action by blocking 'L-type' calcium channels. CCB overdose can be fatal even with appropriate and aggressive therapy. Death ensues from heart block, myocardial suppression, vasoplegia, and shock. Early use of methylene blue (MB) might provide additional means to improve outcomes.

CASE PRESENTATION

A 25-year-old female presented after an attempted suicide. The patient ingested a substantial amount of diltiazem, promethazine, and trazodone. Seven hours following the ingestion, she became profoundly vasoplegic and hypotensive. Despite guideline-based therapy and high doses of vasopressors, she suffered from worsening lactic acidosis and multiorgan failure. Administration of an intravenous bolus dose of MB resulted in a rapid and sustained improvement of vasoplegia, and the patient subsequently went on to make a complete recovery.

DISCUSSION

In addition to calcium channel blockade, CCBs cause vascular smooth muscle relaxation by the production of nitric oxide (NO). In cases of overdose, NO production can be significant. MB is a safe and inexpensive medication with the potential to reverse NO-mediated vasoplegia that is responsible for CCB induced shock state. In parts of the world where access to advanced medical care is not readily available, early use of MB might have a significant role in the management of CCB overdose.