Intravenous Nicardipine

Optimizing nicardipine dosage for effective control of pituitrin-induced hypertension in laparoscopic myomectomy undergoing total intravenous anesthesia

BACKGROUND

This study aimed to determine the median effective dose (ED50) and 95% effective dose (ED95) of nicardipine for treating pituitrin-induced hypertension during laparoscopic myomectomy, providing guidance for the management of intraoperative blood pressure in such patients.

METHODS

Among the initial 40 participants assessed, 24 underwent elective laparoscopic myomectomy. A sequential up-and-down method was employed to ascertain the ED50 of nicardipine based on its antihypertensive efficacy. Nicardipine was initially administered at 6 µg/kg following the diagnosis of pituitrin-induced hypertension in the first patient. Dosing adjustments were made to achieve the desired antihypertensive effect, restoring systolic blood pressure and heart rate to within ± 20% of baseline within 120 s. The dosing increment or reduction was set at 0.5 µg/kg for effective or ineffective responses, respectively. The ED50 and ED95 of nicardipine were calculated using Probit regression by Maximum Likelihood Estimation (MLE) to establish dose-response curves and confidence intervals.

RESULTS

24 patients were included for analysis finally. The ED50 and ED95 of nicardipine for blood pressure control after pituitrin injection were determined. The study found that the ED50 of nicardipine for treating pituitrin-induced hypertension was 4.839 µg/kg (95% CI: 4.569-5.099 µg/kg), and the ED95 was estimated at 5.308 µg/kg (95% CI: 5.065-6.496 µg/kg). Nicardipine effectively mitigated the hypertensive response caused by pituitrin without inducing significant tachycardia or hypotension.

CONCLUSIONS

Nicardipine effectively controlled blood pressure after pituitrin injection during laparoscopic myomectomy, with ED50 and ED95 values established. This research highlights the potential utility of nicardipine in addressing hypertensive responses induced by pituitrin, particularly in clinical settings where pituitrin is routinely administered.

A randomized controlled trial: Comparing blood pressure reduction in hyperacute phase of spontaneous intracerebral hemorrhage by continuous nicardipine infusion with or without a preceding nicardipine bolus dose

Objectives

To determine whether addition of an intravenous bolus dose before continuous nicardipine infusion would improve blood pressure reduction in the hyperacute phase in patients with spontaneous intracerebral hemorrhage (ICH).

Design

Double-blind randomized controlled trial.

Setting

One academic emergency department (ED) in Bangkok, Thailand.

Participants

Adult patients with spontaneous ICH presented to the ED between June 30, 2022, and July 15, 2023.

Interventions

The bolus group (n = 31) received an intravenous bolus dose of nicardipine before nicardipine continuous infusion, whereas the non-bolus group (n = 31) was given a placebo and nicardipine continuous infusion.

Main outcomes

Systolic blood pressure (SBP) within the first hour (being measured every 5 min), neurological deterioration, and infusion dosage at 60 min were assessed.

Results

Basic characteristic features including the mean baseline SBP were not significantly different between the two groups. At 10 min after treatment initiation, the bolus group had a significant decrease in SBP (32.1 ± 13.6 vs 22.3 ± 18.5 mmHg; p-value = 0.020). Moreover, the target SBP of 180 mmHg could be achieved within 10 min in the bolus group compared with 15 min in the non-bolus group. However, the overall mean SBPs were not significantly different, with 152 ± 12 mmHg in the bolus group compared with 150 ± 15 mmHg in the non-bolus group (p-value = 0.564). None of the patients in both groups had neurological deterioration over the first hour of the treatment. The infusion dosages of nicardipine at 1 h were 6.2 mg/h (5.9, 7.7 mg/h) and 6.8 mg/h (5.9, 8.4 mg/h) in the bolus and non-bolus groups, respectively (p-value = 0.618).

Conclusions

Administering a 1-mg bolus dose of nicardipine before continuous nicardipine infusion notably reduces SBP at 10 min. However, the overall SBP does not exhibit a significant decline during the hyperacute phase of spontaneous intracerebral hemorrhage.

Nicardipine is a putative EED inhibitor and has high selectivity and potency against chemoresistant prostate cancer in preclinical models

BACKGROUND

It is imperative to develop novel therapeutics to overcome chemoresistance, a significant obstacle in the clinical management of prostate cancer (PCa) and other cancers.

METHODS

A phenotypic screen was performed to identify novel inhibitors of chemoresistant PCa cells. The mechanism of action of potential candidate(s) was investigated using in silico docking, and molecular and cellular assays in chemoresistant PCa cells. The in vivo efficacy was evaluated in mouse xenograft models of chemoresistant PCa.

RESULTS

Nicardipine exhibited high selectivity and potency against chemoresistant PCa cells via inducing apoptosis and cell cycle arrest. Computational, molecular, and cellular studies identified nicardipine as a putative inhibitor of embryonic ectoderm development (EED) protein, and the results are consistent with a proposed mechanism of action that nicardipine destabilised enhancer of zeste homologue 2 (EZH2) and inhibited key components of noncanonical EZH2 signalling, including transducer and activator of transcription 3, S-phase kinase-associated protein 2, ATP binding cassette B1, and survivin. As a monotherapy, nicardipine effectively inhibited the skeletal growth of chemoresistant C4-2B-TaxR tumours. As a combination regimen, nicardipine synergistically enhanced the in vivo efficacy of docetaxel against C4-2 xenografts.

CONCLUSION

Our findings provided the first preclinical evidence supporting nicardipine as a novel EED inhibitor that has the potential to be promptly tested in PCa patients to overcome chemoresistance and improve clinical outcomes.

Combination Therapy With Nicardipine and Isosorbide Dinitrate to Prevent Spasm in Transradial Percutaneous Coronary Intervention (from the NISTRA Multicenter Double-Blind Randomized Controlled Trial)

Verapamil and nitroglycerin are widely used to prevent radial artery spasm (RAS) during percutaneous cardiovascular procedures. However, these agents are not typically available in most African countries and consequently, isosorbide dinitrate is often the only spasmolytic treatment. Our aim was to compare the efficacy of isosorbide dinitrate alone versus isosorbide dinitrate used together with nicardipine to prevent RAS during transradial coronary procedures. This was a randomized controlled double-blind multicenter trial. Patients (n = 1,523) were randomized to receive either a sole therapy of isosorbide dinitrate (n = 760) or the combination of isosorbide dinitrate and nicardipine (n = 763). Our primary end point was the occurrence of RAS; defined as considerable perceived hindrance of catheter advancement. Our secondary end points were severe RAS; defined as (1) severe arm pain, (2) the need for either morphine or midazolam treatment, and (3) necessity for crossover to the contralateral radial or femoral artery. RAS incidence was reduced with the combination therapy versus isosorbide dinitrate alone (15% vs 25%, p <0.001), with a number needed to treat of 10 patients. There was also a significant reduction in the incidence of the secondary end points with combination therapy (3.6% vs 8.2%, p <0.001), with a number needed to treat of 22 patients. This result was driven by reductions in both femoral crossover (0.5% vs 2.4%, p = 0.003) and the use of morphine or midazolam injections (1.6% vs 3.5%, p = 0.02) with combination therapy. In conclusion, we demonstrated the superiority of the combination therapy of isosorbide dinitrate and nicardipine over isosorbide dinitrate alone in reducing the incidence of RAS.

Use of continuous infusion of nicardipine to control persistent postpartum hypertension: A retrospective study

To evaluate the effect of continuous infusion of nicardipine on the management of uncontrolled blood pressure (BP) during postpartum period. This retrospective study included 209 women diagnosed in hospital with hypertensive disorders during pregnancy and had uncontrolled BP after delivery between January 2018 to December 2020 Uncontrolled BP was defined as persistent elevation of systolic BP ≥ 160 mm Hg or diastolic BP ≥ 110 mm Hg. Patients were divided into 2 groups: nicardipine (N = 53; continuous nicardipine infusion and additional bolus of labetalol or hydralazine) and control (N = 156; consecutive bolus of labetalol or hydralazine). BP data were analyzed using the Mann-Whitney U and χ2 tests by dividing the time interval of 4 hours by the delivery time. The highest BP trends showed that the mean values of both systolic and diastolic BP immediately before delivery were higher in the nicardipine group than in the control. After 8 to 12 hours following delivery, both systolic and diastolic BP were lower in the nicardipine group than in the control. Subsequently, 16 to 20 hours after delivery, both systolic and diastolic BP were significantly lower in the nicardipine group than in the control (137/80 vs 141/84 mm Hg). Initially, the proportions of uncontrolled BP in the nicardipine group were higher than those in the control; however, it then became lower at all time intervals 8 hours after delivery. The proportions of patients who received additional antihypertensive agents and the median cumulative dosages were lower in the nicardipine group than in the control. Continuous infusion of nicardipine can help manage uncontrolled BP during the postpartum period.

High risk and low prevalence diseases: Eclampsia

INTRODUCTION

Eclampsia is a rare partum and puerperal condition that carries a high rate of morbidity and mortality.

OBJECTIVE

This review highlights the pearls and pitfalls of the care of patients with eclampsia, including presentation, evaluation, and evidence-based management in the emergency department (ED).

DISCUSSION

Eclampsia is a hypertensive disease of pregnancy defined by new onset tonic-clonic, focal, or multifocal seizures or unexplained altered mental status in a pregnant or postpartum patient in the absence of other causative etiologies. However, signs and symptoms of preeclampsia and prodromes of eclampsia are often subtle and non-specific, making the diagnosis difficult. Thus, it should be considered in pregnant and postpartum patients who present to the ED. Laboratory testing including complete blood cell count, renal and liver function panels, electrolytes, glucose, coagulation panel, fibrinogen, lactate dehydrogenase, uric acid, and urinalysis, as well as imaging to include head computed tomography, can assist, but these evaluations should not delay management. Components of treatment include emergent obstetric specialist consultation, magnesium administration, and blood pressure control in patients with hypertension. Definitive treatment of eclampsia requires emergent delivery in pregnant patients. If consultants are not in-house, emergent stabilization and immediate transfer are required.

CONCLUSIONS

An understanding of eclampsia can assist emergency clinicians in rapid recognition and timely management of this potentially deadly disease.

Clevidipine as a therapeutic and cost-effective alternative to sodium nitroprusside in patients with acute aortic syndromes

Background:

Sodium nitroprusside is the preferred agent for the treatment of high blood pressure during acute aortic syndrome if blood pressure remains elevated after heart rate control with beta-blockers. The increasing cost of sodium nitroprusside in the USA led us to assess the efficacy and safety of intravenous clevidipine, a calcium channel blocker with quick onset of action, short half-life and significantly lower costs than sodium nitroprusside, in patients presenting with acute aortic syndrome.

Methods:

We performed a retrospective chart review of consecutive patients admitted to the Cleveland Clinic Cardiac Intensive Care Unit from 2013–2016 with a diagnosis of acute aortic syndrome. Patients who received intravenous sodium nitroprusside were compared with those receiving intravenous clevidipine. The primary outcome was a significant difference in blood pressure at one, three and six hours. Secondary outcomes included time to achieving blood pressure target and in hospital mortality with rates of hypotension and bradycardia as safety endpoints.

Results:

A total of 85 patients with suspected acute aortic pathology received clevidipine and 50 received sodium nitroprusside. Clinical and demographic characteristics were similar in both groups, except for a higher incidence of abdominal aortic aneurysm in the clevidipine group and for a trend towards higher use of labetalol in the clevidipine group. There were no significant differences in blood pressure or heart rate at one, three and six hours after starting either infusion. The rates of hypotension, bradycardia and in-hospital mortality did not differ. Time to achieve blood pressure control were also similar between groups.

Conclusion:

Intravenous clevidipine appears to be a safe and effective alternative to sodium nitroprusside for the management of high blood pressure during acute aortic dissection. In the USA, clevidipine could represent a cost effective therapy providing similar outcomes than sodium nitroprusside.

The relaxant effect of nicardipine on the isolated uterine smooth muscle of the pregnant rat

Background

Nicardipine, a calcium channel blocker, is used to treat hypertension in pregnancy or preterm labor. The current study was conducted to investigate the relaxant effects of nicardipine on the isolated uterine smooth muscle of the pregnant rat.

Methods

We obtained uterine smooth muscle strips from pregnant female SD rats. After uterine contraction with oxytocin 10 mU/ml, we added nicardipine (10⁻¹² to 10⁻⁸ M) accumulatively every 20 min. We recorded active tension and frequency of contraction, and calculated EC₅ (effective concentration of 5% reduction), EC₂₅, EC₅₀, EC₇₅, and EC₉₅ of active tension and frequency of contraction using a probit model.

Results

Nicardipine (10⁻¹² to 10⁻⁸ M) decreased active tension and frequency of contraction in a concentration-dependent manner. The EC₅₀ and EC₉₅ of nicardipine in the inhibition of active tension of the uterine smooth muscle were 2.41 × 10⁻¹⁰ M and 3.06 × 10⁻⁷ M, respectively. The EC₅₀ and EC₉₅ of nicardipine in the inhibition of frequency of contraction of the uterine smooth muscle were 9.04 × 10⁻¹¹ and 4.18 × 10⁻⁷ M, respectively.

Conclusions

Nicardipine relaxed and decreased the frequency of contraction of the uterine smooth muscle in a concentration-dependent pattern. It might be possible to adjust the clinical dosage of nicardipine in the obstetric field based on our results, but further clinical studies are needed to confirm them.

Towards precision critical care management of blood pressure in hemorrhagic stroke patients using dynamic linear models

Finding optimal blood pressure (BP) target and BP treatment after acute ischemic or hemorrhagic strokes is an area of controversy and a significant unmet need in the critical care of stroke victims. Numerous large prospective clinical trials have been done to address this question but have generated neutral or conflicting results. One major limitation that may have contributed to so many neutral or conflicting clinical trial results is the "one-size fit all" approach to BP targets, while the optimal BP target likely varies between individuals. We address this problem with the Acute Intervention Model of Blood Pressure (AIM-BP) framework: an individualized, human interpretable model of BP and its control in the acute care setting. The framework consists of two components: one, a model of BP homeostasis and the various effects that perturb it; and two, a parameter estimator that can learn clinically important model parameters on a patient by patient basis. By estimating the parameters of the AIM-BP model for a given patient, the effectiveness of antihypertensive medication can be quantified separately from the patient's spontaneous BP trends. We hypothesize that the AIM-BP is a sufficient framework for estimating parameters of a homeostasis perturbation model of a stroke patient's BP time course and the AIM-BP parameter estimator can do so as accurately and consistently as a state-of-the-art maximum likelihood estimation method. We demonstrate that this is the case in a proof of concept of the AIM-BP framework, using simulated clinical scenarios modeled on stroke patients from real world intensive care datasets.

Hyperinflation of Nitroprusside

Sodium nitroprusside (SNP) is a generically available and rapid-acting intravenous (IV) vasodilator that has been used clinically for decades. Prior to 2013, the cost of SNP was relatively low, and SNP was an affordable option for the treatment of acute hypertension. However, from 2013 to 2017, average wholesale prices for SNP rose to as high as $900 per vial, earning the drug its status as a "hyperinflation drug." Hyperinflation drugs such as SNP pose a significant challenge for pharmacy departments. A multidisciplinary effort involving stakeholders from many backgrounds, including pharmacists, physicians, and nurses, is key to developing an effective plan to address the problem. A therapeutic interchange, wherein a drug with similar efficacy is substituted for another, is often an appropriate strategy in this scenario. Fortunately, alternative drugs with a solid evidence base exist for the management of acute hypertension. The dihydropyridine calcium channel blockers, clevidipine and nicardipine, are IV titratable antihypertensive agents with favorable pharmacokinetic and safety profiles. Various studies indicate that clevidipine and nicardipine are effective alternatives to SNP for indications including hypertensive crisis and postoperative hypertension. Some hospitals have reported significant cost savings without adverse outcomes by substituting clevidipine or nicardipine for SNP. This article is intended to serve as a review of the evidence for clevidipine and nicardipine as potential substitutes for SNP and to provide strategies to successfully implement this therapeutic interchange.

Sodium Nitroprusside as a Hyperinflation Drug and Therapeutic Alternatives

Sodium nitroprusside (SNP) is a generically available and rapid-acting intravenous (IV) vasodilator that has been used clinically for decades. Prior to 2013, the cost of SNP was relatively low, and SNP was an affordable option for the treatment of acute hypertension. However, from 2013 to 2017, average wholesale prices for SNP rose to as high as US$900 per vial, earning the drug its status as a "hyperinflation drug." Hyperinflation drugs pose a significant challenge for pharmacy departments. A multidisciplinary effort involving stakeholders from many backgrounds, including pharmacists, physicians, and nurses, is key to developing an effective cost containment strategy. A therapeutic interchange, wherein a drug with similar efficacy is substituted for another, is often an appropriate strategy to address rising drug costs. Fortunately, alternative drugs with a solid evidence base exist for the management of acute hypertension. The dihydropyridine calcium channel blockers, clevidipine and nicardipine, are IV titratable antihypertensive agents with favorable pharmacokinetic and safety profiles. Various studies indicate that clevidipine and nicardipine are effective alternatives to SNP for indications including hypertensive crisis and postoperative hypertension. Some hospitals have reported significant cost savings without adverse outcomes by substituting clevidipine or nicardipine for SNP. This article is intended to serve as a review of the evidence for clevidipine and nicardipine as potential substitutes for SNP and to provide strategies to successfully implement this therapeutic interchange.

Encapsulation of Nicardipine Hydrochloride and Release from Biodegradable Poly(D,L-lactic-co-glycolic acid) Microparticles by Double Emulsion Process: Effect of Emulsion Stability and Different Parameters on Drug Entrapment

Poly(D,L-lactic-co-glycolic acid) (PLGA) is an important material used in drug delivery when controlled release is required. The purpose of this research is to design and characterize PLGA microparticles (PLGA MPs) implants for the controlled release of nicardipine hydrochloride (NCH) in vitro. This study used the water-in-oil-in-water (w₁/o/w₂) double emulsion and solvent diffusion/evaporation approach to prepare PLGA MPs. Optimal processing conditions were found, such as polymer content, surfactant type, stabilizer concentration, inner and outer aqueous phase volumes, and stirring speed. The PLGA MPs for use as nicardipine hydrochloride (NCH) loading and release had spherical morphology, and the average diameter was smaller than 5.20 ± 0.25 μm. The release kinetics were modeled to elucidate the possible mechanism of drug release. In vitro release studies indicated that the NCH release rate is slow and continuous. PLGA MPs are an interesting alternative drug delivery system, especially for use with NCH for biomedical applications.

The effects of anti-hypertensive drugs and the mechanism of hypertension in vascular smooth muscle cell-specific ATP2B1 knockout mice

ATP2B1 is a gene associated with hypertension. We reported previously that mice lacking ATP2B1 in vascular smooth muscle cells (VSMC ATP2B1 KO mice) exhibited high blood pressure and increased intracellular calcium concentration. The present study was designed to investigate whether lack of the ATP2B1 gene causes a higher response to calcium channel blockers (CCBs) than to other types of anti-hypertensive drugs. Both VSMC ATP2B1 KO and control mice were administered anti-hypertensive drugs while monitoring blood pressure shifts. We also examined the association of nitric oxide synthase (NOS) activity in those mice to investigate whether another mechanism of hypertension existed. VSMC ATP2B1 KO mice exhibited significantly greater anti-hypertensive effects with a single injection of nicardipine, but the effects of an angiotensin II receptor blocker (ARB), an α-blocker and amlodipine on blood pressure were all similar to control mice. However, long-term treatment with amlodipine, but not an ARB, significantly decreased the blood pressure of KO mice compared with control mice. Both mRNA and protein expression levels of the L-type calcium channel were significantly upregulated in KO VSMCs. There were no alterations in neural NOS protein expression of VSMCs or in urinary NO production between the two groups. VSMC ATP2B1 KO mice had a higher response to CCBs for blood pressure-lowering effects than other anti-hypertensive drugs. These results mean that increased intracellular calcium concentration in VSMCs due to lack of ATP2B1 and subsequent activation of L-type calcium channels mainly affects blood pressure and suggests increased susceptibility to CCBs in this type of hypertension.

Nicardipine for Hypertension Following Aortic Coarctectomy or Superior Cavopulmonary Anastomosis

BACKGROUND

Literature on the use of nicardipine, a dihydropyridine calcium channel antagonist, in children recovering from cardiac surgery is sparse and, to our knowledge, nonexistent in children with single ventricle anatomy. We aimed to report our experience with nicardipine in these patient populations.

METHODS

We performed a retrospective review of children recovering from aortic coarctectomy or superior cavopulmonary anastomoses who received nicardipine for hypertension at our institution between 2007 and 2013. Hemodynamic variables prior to and after nicardipine initiation were compared using paired t tests.

RESULTS

Seven children recovering from aortic coarctectomy (median age 8.6 months, range: 1.5 months-7.9 years) and four children recovering from superior cavopulmonary anastomosis (median age: seven months, range: five-nine months) were reviewed. For all patients, at six hours after initiation of nicardipine, mean systolic blood pressure was significantly decreased, 123 ± 19 versus 103 ± 14 mm Hg (P = .001), as were diastolic blood pressure, 68 ± 20 versus 53.5 ± 10 mm Hg (P = .041), and sodium nitroprusside dose, 4.3 ± 2.9 versus 1.3 ± 1.7 mcg/kg/min (P = .002). Further, within 24 hours, serum lactate decreased from 1.45 ± 0.82 to 0.81 ± 0.29 mg/dL (P = .016). Heart rate, blood urea nitrogen, and serum creatinine measurements were statistically unchanged.

CONCLUSIONS

Nicardipine effectively decreased blood pressure without apparent adverse events in a small cohort of children with postoperative hypertension while recovering from aortic coarctectomy or superior cavopulmonary anastomosis. Further research comparing nicardipine to more conventional titratable antihypertensive agents in these patient populations is warranted.

Hemodynamic effects of intravenous nicardipine in severely pre-eclamptic women with a hypertensive crisis

OBJECTIVE

Nicardipine permits rapid control of blood pressure in women with severe pre-eclampsia (PE) and hypertensive crisis. Our objective was to investigate its maternal and fetal hemodynamic effects.

METHODS

Ten severely pre-eclamptic pregnant women who required intravenous nicardipine for severe hypertension were included in this prospective observational trial. Maternal macrocirculation was assessed by transthoracic echocardiography. Maternal microcirculatory perfusion was examined sublingually with the sidestream dark field imaging technique. Fetal hemodynamics were assessed by Doppler examinations of the uteroplacental and fetal circulations. Maternal cardiac output, total vascular resistance, mitral E/A ratio and capillary heterogeneity index, uterine artery pulsatility index and fetal cerebroplacental ratio were considered primary outcomes. Paired measurements, obtained before administration of nicardipine infusion and after stabilization of blood pressure, were compared.

RESULTS

Administration of nicardipine significantly reduced the mean arterial blood pressure (median difference, 26 mmHg; P = 0.002) and total vascular resistance (median difference, 791 dynes × s/cm(5) ; P = 0.002) in all included women. This induced a reflex tachycardia with consequent increase in cardiac output of 1.55 L/min (P  =  0.004). There were no significant changes in the other determinants of maternal or fetal hemodynamic parameters.

CONCLUSIONS

Nicardipine effectively reduces blood pressure through selective afterload reduction that triggers an increase in cardiac output, without affecting maternal diastolic function, or microcirculatory, uteroplacental or fetal perfusion. This hemodynamic response is uniform and predictable. Fetomaternal cardiovascular profiling can be achieved by combining transthoracic echocardiography with obstetric Doppler.

Bradycardia caused by intravenous nicardipine in an elderly patient with acute ischemic infarct

Nicardipine is a dihydropyridine calcium-channel blocker that is frequently used in the acute treatment of hypertension in the emergency department (ED). Reflex sympathetic tachycardia is a well-described side effect of this medication. Two experimental studies and 1 anesthesia case report, however, have previously described nicardipine-induced bradycardia as a very rare side effect. We report the case of an elderly patient with an acute ischemic stroke who developed nicardipine-induced bradycardia in the ED.

Control of hypertension in the critically ill: a pathophysiological approach

Severe acute arterial hypertension can be associated with significant morbidity and mortality. After excluding a reversible etiology, choice of therapeutic intervention should be based on evaluation of a number of factors, such as age, comorbidities, and other ongoing therapies. A rational pathophysiological approach should then be applied that integrates the effects of the drug on blood volume, vascular tone, and other determinants of cardiac output. Vasodilators, calcium channel blockers, and beta-blocking agents can all decrease arterial pressure but by totally different modes of action, which may be appropriate or contraindicated in individual patients. There is no preferred agent for all situations, although some drugs may have a more attractive profile than others, with rapid onset action, short half-life, and fewer adverse reactions. In this review, we focus on the main mechanisms underlying severe hypertension in the critically ill and how using a pathophysiological approach can help the intensivist decide on treatment options.

Optimizing drug therapy in the surgical intensive care unit

This article provides a review of commonly prescribed medications in the surgical ICU, focusing on sedatives, antipsychotics, neuromuscular blocking agents, cardiovascular agents, anticoagulants, and antibiotics. A brief overview of pharmacology is followed by practical considerations to aid prescribers in selecting the best therapy within a given category of drugs to optimize patient outcomes.

Effectiveness of nicardipine for blood pressure control in patients with subarachnoid hemorrhage

OBJECTIVE

The purpose of the study is to determine the effectiveness and safety of nicardipine infusion for controlling blood pressure in patients with subarachnoid hemorrhage (SAH).

METHODS

We prospectively evaluated 52 patients with SAH and treated with nicardipine infusion for blood pressure control in a 29 months period. The mean blood pressure of pre-injection, bolus injection and continuous injection period were compared. This study evaluated the effectiveness of nicardipine for each Fisher grade, for different dose of continuous nicardipine infusion, and for the subgroups of systolic blood pressure.

RESULTS

The blood pressure measurement showed that the mean systolic blood pressure / diastolic blood pressure (SBP/DBP) in continuous injection period (120.9/63.0 mmHg) was significantly lower than pre-injection period (145.6/80.3 mmHg) and bolus injection period (134.2/71.3 mmHg), and these were statistically significant (p < 0.001). In each subgroups of Fisher grade and different dose, SBP/DBP also decreased after the use of nicardipine. These were statistically significant (p < 0.05), but there was no significant difference in effectiveness between subgroups (p > 0.05). Furthermore, controlling blood pressure was more effective when injecting higher dose of nicardipine in higher SBP group rather than injecting lower dose in lower SBP group, and it also was statistically significant (p < 0.05). During the infusion, hypotension and cardiogenic problems were transiently combined in five cases. However, patients recovered without any complications.

CONCLUSION

Nicardipine is an effective and safe agent for controlling acutely elevated blood pressure after SAH. A more systemic study with larger patients population will provide significant results and will bring solid evidence on effectiveness of nicardipine in SAH.

Inhibitory effect of the D(3) dopamine receptor on insulin receptor expression and function in vascular smooth muscle cells

BACKGROUND

Vascular smooth muscle cell (VSMC) proliferation is regulated by numerous hormones and humoral factors. Our previous study found that stimulation of D(1)-like dopamine receptors inhibited insulin receptor expression and function in VSMCs. We hypothesize that there is also an interaction between D(3) dopamine and insulin receptors, i.e., stimulation of the D(3) receptor inhibits insulin receptor expression and function.

METHODS

Receptor expression was determined by immunoblotting, immunohistochemisty, and reverse transcriptase-PCR; VSMC proliferation was determined by 3-(4,5-dimethylthiazol-2-yl)-diphenyl-tetrazolium bromide (MTT) assay and cell number.

RESULTS

Insulin receptor protein is increased in the aorta of D(3) receptor deficient mice. Stimulation of the D(3) receptor inhibited insulin receptor mRNA and protein expression and insulin-mediated VSMC proliferation, and increased protein kinase A (PKA) activity, insulin receptor phosphorylation, and degradation in immortalized aortic VSMCs (A10 cells). These effects were blocked by a PKA inhibitor, indicating that the D(3) receptor-mediated decrease in insulin receptor expression was related to a decrease in transcription/post-transcription and increased degradation, involving PKA signaling.

CONCLUSIONS

D(3) receptor stimulation may be a target to reduce the adverse effect of insulin in hypertension by inhibition of insulin receptor expression and function in arterial VSMCs.

The management of hypertensive emergencies in children after stem cell transplantation

AIM OF THE REVIEW

This work presents a short overview on the available data about drugs that are currently used to treat hypertensive emergencies in children with a focus on incidents after stem cell transplantation. It shows that the pediatric use of all hypotensive agents appears to be mainly based on personal experience of the attending physicians rather than on convincing clinical trials.

METHOD

A literature search was performed in MEDLINE, through PubMed, using the medical subject headings (MeSH) hypertensive emergencies, nifedipine, nicardipine, and children. Further articles were identified by checking cross-references of articles and books.

RESULTS

Hypertensive emergencies in children after stem cell transplantation usually have a renal etiology, because of the treatment with the calcineurin inhibitors cyclosporine and tacrolimus. In these severe cases an immediate action is necessary to avoid possible appearance or exacerbation of endorgan damage. Because of their mechanism of action and a potential nephroprotective effect calcium channel blockers may be particularly suitable in cases of hypertensive emergencies. An intravenous application of nifedipine may compensate the difficulties of accurate dosing, but keeping in mind possible severe side effects and the lack of published experience its use in children is at least questionable. Nicardipine appears to be the hypotensive agent of first choice. In adults, the treatment of hypertensive emergencies with intravenous nicardipine is well-documented, but for an evaluation of safety in pediatric use, the published studies and case reports appear to be barely adequate.

CONCLUSION

The actual treatment approaches vary widely, demonstrating the lack of hard science on which current treatment of hypertensive emergencies in children is based. The hypotensive agent for the individual situation should be chosen considering the properties, side effects, the limited experiences with its use and the patient's anamnesis.

Intravenous to Oral Conversion of Antihypertensives: A Toolkit for Guideline Development

Objective:

To provide a toolkit of information for hospitals to use in developing intravenous to oral conversion protocols for antihypertensives.

Data Sources:

Articles describing intravenous to oral conversion protocols for any therapeutic category were identified in an English-language MEDLINE search (1990-April 2010) using a wide variety of MeSH terms. References from selected articles were reviewed for additional material.

Study Selection and Data Extraction:

Experimental and observational English-language studies and review articles that focused on oral transition of intravenous drugs were selected.

Data Synthesis:

Most of the literature on conversion from intravenous to oral formulations involves antimicrobials. There is considerable evidence documenting reduced costs and improved patient flow through the health-care system following implementing these protocols with drugs like antimicrobials, histamine-2 receptor antagonists, and proton pump inhibitors. Although antihypertensives have not been studied, principles and implementation strategies used for other drug classes can be applied to antihypertensives. Guidance is provided on framing the problem, issues surrounding oral absorption principles, information pertaining to oral conversion in specific disease slates, and implementation and documentation strategies. Detailed tables of oral and intravenous antihypertensives are provided.

Conclusions:

We recommend that hospitals consider developing protocols on conversion of intravenous to oral antihypertensives in an attempt to reduce unnecessarily prolonged intravenous therapy. Information contained in this article can be used as a toolkit to select information specific to the characteristics of individual health-care systems.

Sympathetic Nonadrenergic Transmission Contributes to Autonomic Dysreflexia in Spinal Cord–Injured Individuals

Autonomic dysreflexia is a hypertensive episode in spinal cord–injured individuals induced by exaggerated sympathetic activity and thought to be α-adrenergic mediated. α-Adrenoceptor antagonists have been a rational first choice; nevertheless, calcium channel blockers are primarily used in autonomic dysreflexia management. However, α-adrenoceptor blockade may leave a residual vasoconstrictor response to sympathetic nonadrenergic transmission unaffected. The aim was to assess the α-adrenergic contribution and, in addition, the role of supraspinal control to leg vasoconstriction during exaggerated sympathetic activity provoked by autonomic dysreflexia in spinal cord–injured individuals and by a cold pressure test in control individuals. Upper leg blood flow was measured using venous occlusion plethysmography during supine rest and during exaggerated sympathetic activity in 6 spinal cord–injured individuals and 7 able-bodied control individuals, without and with phentolamine (α-adrenoceptor antagonist) and nicardipine (calcium channel blocker) infusion into the right femoral artery. Leg vascular resistance was calculated. In spinal cord–injured individuals, phentolamine significantly reduced the leg vascular resistance increase during autonomic dysreflexia (8±5 versus 24±13 arbitrary units; P =0.04) in contrast to nicardipine (15±10 versus 24±13 arbitrary units; P =0.12). In controls, phentolamine completely abolished the leg vascular resistance increase during a cold pressure test (1±2 versus 18±14 arbitrary units; P =0.02). The norepinephrine increase during phentolamine infusion was larger ( P =0.04) in control than in spinal cord–injured individuals. These results indicate that the leg vascular resistance increase during autonomic dysreflexia in spinal cord–injured individuals is not entirely α-adrenergic mediated and is partly explained by nonadrenergic transmission, which may, in healthy subjects, be suppressed by supraspinal control.

D1-like receptors inhibit insulin-induced vascular smooth muscle cell proliferation via down-regulation of insulin receptor expression

OBJECTIVE

Vascular smooth muscle cell (VSMC) proliferation is central to the development of vascular diseases, including hypertension, which is regulated by numerous hormones and humoral factors. Our previous study showed that the stimulatory effect of norepinephrine on VSMC proliferation is inhibited by D1-like receptors and the D3 dopamine receptor, a member of the D2-like receptor family. Insulin is a proliferative hormone but it is not known if there is any interaction between insulin and D1-like receptors. We hypothesized that Dl-like receptors may have an inhibitory effect on the insulin-induced VSMC proliferation; aberrant insulin and Dl-like receptor functions could be involved in the pathogenesis of essential hypertension.

METHODS

VSMC proliferation was determined by [H]-thymidine incorporation; insulin receptor mRNA and protein expressions were determined by RT-PCR, immunoblotting, and immunohistochemistry.

RESULTS

Insulin increased VSMC proliferation in immortalized aortic A10 cells, determined by [H]-thymidine incorporation. Although the D1-like receptor, by itself, had no effect on VSMC proliferation, stimulation with fenoldopam, a D1-like receptor agonist, inhibited the stimulatory effect of insulin. The inhibitory effect of fenoldopam on insulin-mediated VSMC proliferation was receptor specific, because its effect could be blocked by SCH23390, a D1-like receptor antagonist. Fenoldopam also inhibited insulin receptor mRNA and protein expression, which was time dependent and concentration dependent. A PKC or MAP kinase inhibitor blocked the inhibitory effect of fenoldopam on insulin receptor expression, indicating that PKC and MAP kinase were involved in the signaling pathway.

CONCLUSION

The inhibitory effect of D1-like receptors on insulin-mediated VSMC proliferation may play an important role in the regulation of blood pressure.

Nicardipine: a hypotensive dihydropyridine-type calcium antagonist with a peculiar cerebrovascular profile

Control of blood pressure protects against the development of cerebrovascular lesions, stroke, and vascular dementia (VaD). Cerebrovascular disease is increasingly recognized as a cause of cognitive impairment and dementia primarily in the elderly. Nicardipine is a dihydropyridine-type calcium channel blocker (CCB) with a peculiar cerebrovascular profile developed approximately 30 years ago. This study has reviewed the main controlled clinical studies investigating the use of nicardipine in pathologies associated with cerebrovascular injury, such as subarachnoid haemorrhage (SAH), acute stroke, and VaD. SAH is a main cerebrovascular indication of CCBs. In this indication, CCBs prevent vasospasm and improve clinical outcomes. Nimodipine represents the CCB more investigated in this indication. Former studies did not demonstrate a clear advantage of nicardipine versus nimodipine in SAH. A more recent approach using implants of nicardipine prolonged-release showed a decreased incidence of vasospasm, delayed ischemic deficits, and improved clinical outcome after severe SAH. Controlled trials have shown the effectiveness of the drug in preventing stroke. Increasing evidence suggests some benefit of some CCBs in VaD or mixed degenerative and vascular dementia. In this setting, nicardipine has been investigated in approximately 6,000 patients, with an improvement of cognitive deterioration in more than 60% of patients treated. The pronounced anti-hypertensive activity of nicardipine and its safety and effectiveness in cognitive domain suggest its reconsideration in the treatment of cognitive impairment of vascular origin as well as for reducing the risk of recurrent stroke in patients at high risk of it.

PROSPECTIVE RANDOMIZED COMPARISON OF SAFETY AND EFFICACY OF NICARDIPINE AND NITROPRUSSIDE DRIP FOR CONTROL OF HYPERTENSION IN THE NEUROSURGICAL INTENSIVE CARE UNIT

OBJECTIVE

The calcium channel blocker nicardipine (NC) is effective for acute control of hypertension. However, efficacy and safety in neurosurgical patients have not been evaluated. We sought to compare NC with the most commonly used agent, sodium nitroprusside (SNP), in patients with subarachnoid or intracerebral hemorrhage.

METHODS

We performed a prospective randomized comparison of the safety and efficacy of NC and SNP in patients with subarachnoid or intracerebral hemorrhage. We assessed the number of dose adjustments per patient day, proportion of time within set blood pressure parameters, use of additional medications for blood pressure control, clinical outcome, and drug-related complications.

RESULTS

Two hundred patients were screened and 163 patients were randomized, including 89 in the SNP group and 74 in the NC group. In 107 patients, intravenous blood pressure control was started; 60 of these patients received SNP and 47 received NC. When analyzed by intent to treat, patients randomized to NC had fewer dose adjustments per day: 5.7 versus 8.8 in the nitroprusside group (P = 0.0012, Wilcoxon rank-sum test). There were fewer additional medications per day to maintain blood pressure control in the NC group: 1.4 versus 1.9 for SNP (P = 0.043, Wilcoxon rank-sum test). Blood pressure control was similar (NC, 66% of the time within parameters; SNP, 69%). “As-treated” analysis maintained the apparent advantage of NC.

CONCLUSION

When used for control of hypertension in patients with subarachnoid or intracerebral hemorrhage, NC and SNP were both safe and effective, but patients on an NC drip required fewer dose adjustments and fewer additional medications.

Diagnosis and management of labile blood pressure during acute cerebrovascular accidents and other hypertensive crises

It is estimated that with more than 40 million adults in the United States having uncontrolled hypertension, the risk of developing ischemic or hemorrhagic stroke in this population is significant. In addition, roughly 1 of 100 patients with essential hypertension will experience a hypertensive crisis during their lifetime, and these accelerated hypertensive emergencies and urgencies complicate more than 27% of all acute medical problems in patients presenting to emergency departments (EDs) in the United States. Arterial hypertension, a prominent feature of acute stroke syndrome, usually declines spontaneously within a few days, but its presence at hospital admission or its acute development during hospitalization is often associated with worsening stroke outcome and early mortality. Control of hypertension in patients with subarachnoid and intracerebral hemorrhage, both forms of acute stroke, is directed at maintaining adequate cerebral blood flow to minimize ischemic damage and control intracerebral pressure while reducing the risk of rebleeding and developing cerebrovasospasm. Inappropriate lowering of the blood pressure in acute stroke may increase neurologic damage. However, adequate blood flow around the central area of the acute ischemic stroke or penumbra may result in ischemic cells being salvaged. Clinicians must be mindful that accelerated hypertension is associated with other types of patients seen in the ED, such as perioperative patients and patients with traumatic head injuries.

New therapeutic perspectives with clevidipine: an ultra-short-acting intravenous Ca2+channel blocker

Intravenous antihypertensive agents are used in clinical situations in which the immediate, precise control of blood pressure is a clinical necessity. Clevidipine is a new, vascular-selective, dihyrdopyridine Ca(2+) channel blocker, which exerts its hemodynamic effects through selective arterial vasodilation without effects on the venous circulation. Because it is a potent coronary vasodilator, reduction in mean arterial pressure does not impair coronary perfusion. The unique properties of clevidipine include an ultra-short pharmacodynamic duration of action and a half-life after intravenous administration of approximately 2 min, resulting in very rapid onset and offset of antihypertensive effects. In clinical trials performed in patients undergoing cardiac surgery, clevidipine proved superior to nitroprusside and nitroglycerin in maintaining blood pressure within predetermined ranges during the perioperative period. Its safety profile is comparable to nicardipine and nitroglycerin and, in one study, was associated with reduced 30-day mortality compared with nitroprusside. Clevidipine constitutes a useful addition to available intravenous agents and could prove particularly valuable in circumstances that require the ability to rapidly terminate the blood pressure-lowering effects of administered agents.