Urapidil. A reappraisal of its use in the management of hypertension

Poloxamer based Urapidil Loaded Chitosan Microparticle in Approach to Improve the Mechanical Strength by Tensile Strength and Entrapment Determination

Background:

The literature review highlighted the issues related to the poor mechanical strength of chitosan-based microparticles. In an attempt to resolve the stated drawback, the microparticles are prepared with a suitable combination of poloxamer-188 (pluronic) and chitosan-based hydrogels.

Objective:

The current study deals with urapidil-loaded chitosan microparticles incorporating chitosan-based hydrogels and small polyanionic electrolytes. The mechanical strength was ascertained by entrapment efficiency and texture analyzer.

Method:

Chitosan-based hydrogels and the combination of poloxamer and further microparticles are prepared by counter-ion aggregation technique in polyanionic electrolyte medium (20 % w/v). During the preparation, poloxamer is incorporated to improve the mechanical strength, which is ascertained in terms of adhesive strength (tensile strength) by texture analyzer and entrapment efficiency. The prepared microparticles are also subjected to micrometric studies, swelling index, surface morphology study, drug-polymer interaction study, and zeta analysis.

Result:

It was observed that there is a remarkable increase in entrapment efficiency (maximum of 78.56 % from SSP4) with the progressive increase in poloxamer-188. In addition to that, adhesive strength was also studied by a texture analyzer for all microparticles. Sodium citrate-based products exhibited superior adhesive strength values compared to sodium sulfate and sodium tripolyphosphate-based and signified the incorporation of poloxamer-188. A significant finding was also recorded for the swelling properties to microenvironmental pH attributed to polyanions. It observed Sodium TPP microparticles continued to swell in phosphate buffer pH 6.8. Zeta value was found to be maximum with -5.2 mV; it could further be improved by adding electrolytes. TPP4 showed a comparatively larger particle size of 8.07 µm. Polydispersity index value ascertained homogenous dispersion of microparticles. SEM study revealed prominent porous surfaces for sodium tripolyphosphate microparticles.

Conclusion:

The study revealed that the addition of poloxamer-188 improved the mechanical strength, identified by entrapment efficiency and texture analysis. SCP4 microparticle was found to be the best formulation among all.

In Silico Factorial Screening and Optimization of Chitosan Based Gel for Urapidil Loaded Microparticle using Reduced Factorial Design

OBJECTIVE

Literature study revealed the poor mechanical strength of chitosan-based microparticles. Our research aimed at developing sufficient strength of microparticle with a suitable concentration of chitosan and non-ionic surfactants such as poloxamer-188 (pluronic). It also aimed to develop and study the effect of variables for prepared microparticles utilizing insilico screening methodology, such as reduced factorial design, followed by optimization.

METHODS

Preliminary trial batches were prepared with variable concentration of chitosan and poloxamer-188 utilizing cross-linked ion-gelation technique. A 20% w/v sodium citrate solution was used as a cross-linking solution. The resolution-IV of 24-1 reduced factorial design was selected to screen the possible and significant independent variables or factors in the dosage form design. A total number of eight runs were suggested by statistical software and responses were recorded. The responses such as spreadability, pH, viscosity and percentage of drug released at 12 h were considered in the screening study. Based on the result, selected factors were included in the optimization technique, including graphical and numerical methods.

RESULTS

The signified factors based on reduced two-level factorial screening design with randomized subtype, were identified by Half-normal and Pareto chart. Mathematical fitting and analysis were performed by the factorial equation during the optimization process. The validation and fitting of models were suggested and evaluated by p-value, adjusted R2, and predicted R2 values. The significant and non-significant terms were evaluated, followed by finding the optimal concentration and region with yellow color highlighted in an overlay plot. Based on the data obtained by the overlay study, the final formulation batch was prepared and the observed value was found to be pretty much nearer as compared to predicted values. Drug-polymer interaction study included attenuated total reflectance, differential scanning calorimetry, and X-Ray diffraction study.

CONCLUSION

The principal of the study design was based on finding the prefixed set parameter values utilizing the concept of in-silico screening technique and optimization with a minimal number of trials and study expenses. It concluded that Poloxamer-188 (0.94%), chitosan (2.38%), swelling time (1.81 h), and parts of chitosan (78.51%) in a formulation batch would fulfill the predetermined parameter with specific values.

Retrospective analysis of risk factors of hypotensive bradycardic events during shoulder arthroscopic surgery under interscalene blockade in the sitting position

Background

Hypotensive bradycardic events (HBEs) are a frequent adverse event in patients who underwent shoulder arthroscopic surgery under interscalene block (ISB) in the sitting position. This retrospective study was conducted to investigate the independent risk factors of HBEs in shoulder arthroscopic surgery under ISB in the sitting position.

Methods

A total of 2549 patients who underwent shoulder arthroscopic surgery under ISB and had complete clinical data were included in the study. The 357 patients who developed HBEs were included in the HBEs group, and the remaining 2192 in the non-HBEs group. The potential risk factors for HBEs, such as age, sex, past medical history, anesthetic characteristics, and intraoperative medications were collected and compared between the groups. Statistically significant variables were included in a logistic regression model to further evaluate the independent risk factors for HBEs in shoulder arthroscopic surgery under ISB.

Results

The incidence of HBEs was 14.0% (357/2549). Logistic regression analysis revealed that the intraoperative use of hydralazine (odds ratio [OR] 4.2; 95% confidence interval [CI] 2.9–6.3), propofol (OR 2.1; 95% CI 1.3–3.6), and dexmedetomidine (OR 3.9; 95% CI 1.9–7.8) before HBEs were independent risk factors for HBEs in patients who received shoulder arthroscopic surgery under ISB.

Conclusions

The intraoperative use of antihypertensives such as hydralazine and sedatives such as propofol or dexmedetomidine leads to increased risk of HBEs during shoulder arthroscopic surgery under ISB in the sitting position.

Peri-operative management of pheochromocytoma with intravenous urapidil to prevent hemodynamic instability: A 17-year experience

Background and Aims

Surgery for pheochromocytoma (PCC) can cause excessive catecholamine release with severe hypertension. Alpha blockade is the mainstay of preoperative management. The aim of this study was to evaluate the efficacy and tolerance of intra-venous (IV) urapidil, a competitive short acting α1 receptor antagonist, in the prevention of peri-operative hemodynamic instability of patients with PCC.

Material and Methods

This retrospective observational study included 75 patients (79 PCC) for PCC removal surgery from 2001 to 2017 at the Bordeaux University Hospital. They received, 3 days before surgery, continuous intravenous infusion of urapidil with stepwise increase to the maximum tolerated dose. Urapidil was maintained during the procedure and stopped after clamping the adrenal vein. Plasma catecholamine concentrations were measured during surgery. Hypertensive peaks (SAP >160 mmHg) and tachycardia >100 beats/min were treated with boluses of nicardipine 2 mg and esmolol 0.5 mg/kg.

Results

We recorded 20/79 (25%) cases with systolic arterial pressure (SAP) >180 mmHg. Only 11/79 (14%) had hypotension with SAP <80 mmHg. Peaks of catecholamine secretions were observed preferentially during peritoneal insufflation and tumor dissection (P < 0.05). A correlation was found between tumor size (mm) and the highest norepinephrine levels [r = 0.288, P = 0.015], and between hypertensive peaks (mmHg) and the highest norepinephrine levels [r = 0.45, P = 0.017]. No mortality was reported. The median [range] postoperative hospital stay was 4 [2-9] days.

Conclusion

IV urapidil limits hypertensive and hypotensive peaks during PCC surgery, and corresponds to surgical imperatives allowing a short hospital stay, due to its "on-off" effect.

Reversal of cardiac, vascular, and renal dysfunction by non-quinazoline α1-adrenolytics in DOCA-salt hypertensive rats: a comparison with prazosin, a quinazoline-based α1-adrenoceptor antagonist

We investigated the therapeutic effect of MH-76 and MH-79, which are non-quinazoline α1-adrenoceptor antagonists with an additional ability to stimulate the nitric oxide (NO)/cyclic guanosine monophosphate (cGMP)/K + pathway, on deoxycorticosterone acetate (DOCA)-salt induced hypertension in rats. Prazosin was used as a reference compound, as quinazoline-based α1-adrenolytics may potentially exert unfavorable proapoptotic and necrotic effects. DOCA-salt hypertension was induced by DOCA (20 mg/kg s.c., twice weekly) administration plus 1% NaCl and 0.2% KCl solutions in drinking water for 12 weeks. The studied compounds MH-76, MH-79 (10 mg/kg i.p.) or prazosin (0.4 mg/kg i.p.) were administered to the DOCA-salt-treated rats, starting from the 6th week of DOCA-salt treatment and continuing for 6 weeks. This study showed that the administration of MH-79 and, to a lesser extent, MH-76 decreased elevated systolic blood pressure and heart rate, reduced heart and kidney hypertrophy, and reversed the histopathological alterations of the heart, kidney, and vessels in DOCA-salt hypertensive rats. MH-79 reversed endothelial dysfunction, which reduced inflammatory cell infiltration, arteriosclerotic alterations in renal and coronary arteries, and tubulointerstitial fibrosis. Prazosin showed a potent hemodynamic effect and reduced cardiac and renal fibrosis but exerted detrimental effects on blood vessels, potentiating fibroplasia of the media of the intrarenal artery and causing calcification of coronary arteries. Prazosin did not reverse endothelial dysfunction. Our results show the beneficial effect of non-quinazoline α1-adrenolytics on cardiac, vascular, and renal dysfunction in DOCA-salt hypertensive rats. Our findings also support the idea that targeting endothelial protection and endothelial integrity would yield beneficial effects against cardiac, blood vessel and renal injury related to hypertension.

Management of Blood Pressure During and After Recanalization Therapy for Acute Ischemic Stroke

Ischemic stroke is a common neurologic condition and can lead to significant long term disability and death. Observational studies have demonstrated worse outcomes in patients presenting with the extremes of blood pressure as well as with hemodynamic variability. Despite these associations, optimal hemodynamic management in the immediate period of ischemic stroke remains an unresolved issue, particularly in the modern era of revascularization therapies. While guidelines exist for BP thresholds during and after thrombolytic therapy, there is substantially less data to guide management during mechanical thrombectomy. Ideal blood pressure targets after attempted recanalization depend both on the degree of reperfusion achieved as well as the extent of infarction present. Following complete reperfusion, lower blood pressure targets may be warranted to prevent reperfusion injury and promote penumbra recovery however prospective clinical trials addressing this issue are warranted.

A multicenter, randomized, trial comparing urapidil and nitroglycerin in multifactor heart failure in the elderly

BACKGROUND

Multifactor heart failure is a common life-threatening event in elderly patients and often complicated by concomitant hypertension and diabetes mellitus (DM). The aim of this study was to evaluate whether α1-blocker, urapidil, provides additional therapeutic benefits compared to nitroglycerin (NG) in treatment of multifactor heart failure complicated by hypertension and DM in elderly patients.

METHODS

Seventy-two elderly consecutive patients were randomized into 2 groups that received treatment with urapidil or NG. All patients were monitored for blood pressure (BP) and heart rate and received tests for metabolic activity and cardiovascular function.

RESULTS

Patients receiving urapidil had significantly lower systolic BP than their counterparts in NG group (P < 0.05). Moreover, patients in urapidil group showed lower N-terminal pro-B-type natriuretic peptide levels but higher ejection fraction (t = 2.206, P < 0.05), cardiac index (t = 3.13, P < 0.05) and left end-diastolic volume (t = -3.104, P < 0.05) compared to NG group. Although both urapidil and NG decreased fasting plasma glucose (FPG) levels, there was no significant difference of FPG levels between these 2 groups.

CONCLUSIONS

Urapidil demonstrated better efficacy than NG on lowering and stabilizing systolic BP, attenuating cardiac afterload and improving cardiac function. Both NG and urapidil significantly reduced FPG levels in multifactor heart failure patients with DM. Urapidil is a therapeutic option for the multifactor heart failure patients complicated with hypertension and DM.

Chronomodulated drug delivery system of urapidil for the treatment of hypertension

Introduction:

Hypertension is a disease which shows circadian rhythm in the pattern of two peaks, one in the evening at about 7pm and other in the early morning between 4 am to 8 am. Conventional therapies are incapable to target those time points when actually the symptoms get worsened. To achieve drug release at two time points, chronomodulated delivery system may offer greater benefits.

Materials and methods:

The chronomodulated system comprised of dual approach; immediate release granules (IRG) and pulsatile release mini-tablets (PRM) filled in the hard gelatin capsule. The mini-tablets were coated using Eudragit S-100 which provided the lag time. To achieve the desired release, various parameters like coating duration and coat thickness were studied. The immediate release granules were evaluated for micromeritical properties and drug release, while mini-tablets were evaluated for various parameters such as hardness, thickness, friability, weight variation, drug content, and disintegration time and in-vitro drug release. Compatibility of drug-excipient was checked by fourier transform infrared spectroscopy and Differential scanning calorimetry studies and pellets morphology was done by Scanning electron microscopy studies.

Results:

The in-vitro release profile suggested that immediate release granules gives drug release within 20 min at the time of evening attack while the programmed pulsatile release was achieved from coated mini-tablets after a lag time of 9hrs, which was consistent with the demand of drug during early morning hour attack. Pellets found to be spherical in shape with smooth surface. Moreover compatibility studies illustrated no deleterious reaction between drug and polymers used in the study.

Conclusions:

The dual approach of developed chronomodulated formulation found to be satisfactory in the treatment of hypertension.

Anesthetic considerations on adrenal gland surgery

Adrenal gland surgery needs a multidisciplinary team including endocrinologist, radiologist, anesthesiologist, and surgeon. The indications for adrenal gland surgery include hormonal secreting and non-hormonal secreting tumors. Adrenal hormonal secreting tumors present to the anesthesiologist unique challenges requiring good preoperative evaluation, perioperative hemodynamic control, corrections of all electrolytes and metabolic abnormalities, a detailed and careful anesthetic strategy, overall knowledge about the specific diseases, control and maintaining of postoperative adrenal function, and finally a good collaboration with other involved colleagues. This review will focus on the endocrine issues, as well as on the above-mentioned aspects of anesthetic management during hormone secreting adrenal gland tumor resection.

Biofunctional studies of new 2-methoxyphenylpiperazine xanthone derivatives with α₁-adrenolytic properties

BACKGROUND

The aim of this study was to assess the selectivity of the studied xanthone derivatives for α1-adrenoceptor subtypes (α1A, α1B, α1D, α1L) in functional experiments in order to verify if they possess any selectivity for a distinct subtype of α1-adrenoceptor. Moreover, several pharmacological tests were carried out to assess whether they reveal other than α1-adrenoceptor blocking properties such as: antagonistic for 5-HT2 receptors, vasorelaxant or spasmolytic.

METHODS

The influence on α1A-adrenoceptors was examined in biofunctional studies employing isolated rat vas deferens, on α1B-adrenoceptors in guinea-pig spleen, on α1D-adrenoceptors in rat aorta, and on α1L-adrenoceptors in rabbit spleen. Affinity for 5-HT2 receptors was measured in radioligand binding assay, whereas antagonistic potency for 5-HT2 receptors was studied on isolated rat aorta. Vasorelaxant effect of tested compounds was assessed in functional study employing rat aorta, whereas direct spasmolytic activity was investigated using the isolated rabbit small intestine.

RESULTS

The present study provides evidences that the tested 2-methoxyphenylpiperazine xanthone derivatives are non-selective α1-adrenoceptor blockers. However, at higher concentrations the direct spasmolytic effect could enhance their hypotensive activity. The obtained results indicate that the studied xanthones possessed weak calcium entry blocking activity, as well as antagonistic properties for 5-HT2A receptors.

CONCLUSIONS

The results of the present study support the idea that the hypotensive activity of the studied compounds is related to their α1-adrenolytic properties.

Optimal perioperative management of arterial blood pressure

Perioperative blood pressure management is a key factor of patient care for anesthetists, as perioperative hemodynamic instability is associated with cardiovascular complications. Hypertension is an independent predictive factor of cardiac adverse events in noncardiac surgery. Intraoperative hypotension is one of the most encountered factors associated with death related to anesthesia. In the preoperative setting, the majority of antihypertensive medications should be continued until surgery. Only renin-angiotensin system antagonists may be stopped. Hypertension, especially in the case of mild to moderate hypertension, is not a cause for delaying surgery. During the intraoperative period, anesthesia leads to hypotension. Hypotension episodes should be promptly treated by intravenous vasopressors, and according to their etiology. In the postoperative setting, hypertension predominates. Continuation of antihypertensive medications and postoperative care may be insufficient. In these cases, intravenous antihypertensive treatments are used to control blood pressure elevation.

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.

[Use of injectable urapidil in pregnancy-induced hypertension and preeclampsia]

OBJECTIVE

To evaluate the efficacy and tolerance of injectable urapidil (Eupressyl(®)) for the treatment of severe pregnancy-associated arterial hypertension.

MATERIALS AND METHODS

We carried out a prospective study of 100 cases encompassing the various types of severe pregnancy-associated arterial hypertension, with clinical and biological monitoring of the mother and the collection of neonatal data. Treatment was initiated if the blood pressure was higher than 160/110mmHg and efficacy was defined as a lowering of blood pressure to 150/100mmHg or below.

RESULTS

Treatment with urapidil alone was effective in 80 cases (80%). In 20% of cases, essentially the most severe forms of preeclampsia, efficacy was achieved only if urapidil was associated with labetalol or if urapidil was replaced with nicardipine. We observed no material complications other than two cases of hypotension due to excessively rapid administration of a bolus of nicardipine to replace urapidil treatment.

CONCLUSION

Injectable urapidil seems to be an antihypertensive agent that is easy to use and effective in 80% of cases and that has very few secondary effects on the mother or the foetus. Further comparative studies are required to determine the potential of this drug for use in the management of pregnancy-associated hypertension.

Pharmacological management of hypertensive emergencies and urgencies: focus on newer agents

INTRODUCTION

Hypertensive crises are categorized as hypertensive emergencies and urgencies depending on the presence of acute target-organ damage; the former are potentially life-threatening medical conditions, requiring urgent treatment under close monitoring. Although several short-acting intravenous antihypertensive agents are approved for this purpose, until recently little evidence from proper trials on the relative merits of different therapies was available.

AREAS COVERED

This article discusses in brief the pathophysiology, epidemiology and diagnostic approach of hypertensive crises and provides an extensive overview of established and emerging pharmacological agents for the treatment of patients with hypertensive emergencies and urgencies.

EXPERT OPINION

Agents such as sodium nitroprusside, nitroglycerin and hydralazine have been used for many years as first-line options for patients with hypertensive emergencies, although their potential adverse effects and difficulties in use were well known. With time, equally potent and less toxic alternatives, including nicardipine, fenoldopam, labetalol and esmolol are increasingly used worldwide. Recently, clevidipine, a third-generation dihydropyridine calcium-channel blocker with unique pharmacodynamic and pharmacokinetic properties was added to our therapeutic armamentarium and was shown in clinical trials to reduce mortality when compared with nitroprusside. In view of such evidence, a change in pharmacological treatment practices for hypertensive crises toward newer and safer agents is warranted.

Urapidil, a dual-acting antihypertensive agent: Current usage considerations

Despite the availability of a wide range of effective blood pressure (BP)-lowering agents, a substantial proportion of patients with hypertension fail to achieve target BP levels. The majority of patients with hypertension need a combination of two or more drugs to achieve BP targets and choice of second-line or subsequent-line therapy is an important consideration in hypertension management. Alpha-1-adrenoreceptor antagonists (alpha-blockers) have a BP-lowering effect broadly similar to the other antihypertensive drug classes and are effective as add-on therapy in patients with inadequately controlled hypertension. Alpha-blockers may also have therapeutic benefits that go beyond BP control, including improvements in lipid profile and glucose metabolism, as well as reducing the symptoms of benign prostatic hyperplasia. Urapidil has an alpha-blocking effect but, unlike other alpha-blockers, also has a central sympatholytic effect mediated via stimulation of serotonin 5HT(1A) receptors in the central nervous system. Several studies have suggested that oral urapidil is effective and well tolerated when used as second-line therapy in patients with BP inadequately controlled with other agents. Urapidil has also been shown to improve glucose and lipid metabolism in hypertensive patients with concomitant diabetes and/or hyperlipidemia. Intravenous urapidil is effective in the treatment of hypertensive crises, perioperative hypertension, and pre-eclampsia and may have a potential role in the management of acute stroke. In this review, the use of alpha-blockers in hypertension is discussed, with particular focus on urapidil for the lowering of BP in a variety of clinical settings.

Severe hypertension in children and adolescents: pathophysiology and treatment

Severe, symptomatic hypertension occurs uncommonly in children, usually only in those with underlying congenital or acquired renal disease. If such hypertension has been long-standing, then rapid blood pressure reduction may be risky due to altered cerebral hemodynamics. While many drugs are available for the treatment of severe hypertension in adults, few have been studied in children. Despite the lack of scientific studies, some agents, particularly continuous intravenous infusions of nicardipine and labetalol, are preferred in many centers. These agents generally provide the ability to control the magnitude and rapidity of blood pressure reduction and should--in conjunction with careful patient monitoring--allow the safe reduction of blood pressure and the avoidance of complications. This review provides a summary of the underlying causes and pathophysiology of acute severe hypertension in childhood as well as a detailed discussion of drug treatment and the optimal clinical approach to managing children and adolescents with acute severe hypertension.

Adverse drug reactions in patients with phaeochromocytoma: incidence, prevention and management

The dangers of phaeochromocytomas are mainly due to the capability of these neuroendocrine tumours to secrete large quantities of vasoactive catecholamines, thereby increasing blood pressure and causing other related adverse events or complications. Phaeochromocytomas are often missed, sometimes only becoming apparent during therapeutic interventions that provoke release or interfere with the disposition of catecholamines produced by the tumours. Because phaeochromocytomas are rare, evidence contraindicating use of specific drugs is largely anecdotal or based on case reports. The heterogeneous nature of the tumours also makes adverse reactions highly variable among patients. Some drugs, such as dopamine D(2) receptor antagonists (e.g. metoclopramide, veralipride) and beta-adrenergic receptor antagonists (beta-blockers) clearly carry high potential for adverse reactions, while others such as tricyclic antidepressants seem more inconsistent in producing complications. Other drugs capable of causing adverse reactions include monoamine oxidase inhibitors, sympathomimetics (e.g. ephedrine) and certain peptide and corticosteroid hormones (e.g. corticotropin, glucagon and glucocorticoids). Risks associated with contraindicated medications are easily minimised by adoption of appropriate safeguards (e.g. adrenoceptor blockade). Without such precautions, the state of cardiovascular vulnerability makes some drugs and manipulations employed during surgical anaesthesia particularly dangerous. Problems arise most often when drugs or therapeutic procedures are employed in patients in whom the tumour is not suspected. In such cases, it is extremely important for the clinician to recognise the possibility of an underlying catecholamine-producing tumour and to take the most appropriate steps to manage and treat adverse events and clinical complications.

Differential effects of urapidil and doxazosin on heart rate

OBJECTIVE

Although alpha-blockers are effective in lowering blood pressure, they may increase heart rate, an unwanted effect that could negatively affect outcome. However, the alpha-blocker urapidil might not increase heart rate due to its additional effect on 5-HT1A receptors. Therefore, we compared the effects of urapidil on heart rate with those of another alpha-blocker, doxazosin.

METHODS

We performed a randomised, double-blind, placebo-controlled, cross-over study in 12 healthy males who received single oral doses of 60 mg urapidil, 4 mg doxazosin and placebo. Four hours following drug intake, heart rate and blood pressure were measured at rest and during exercise.

RESULTS

Both doxazosin and urapidil decreased blood pressure to the same extent. Compared to placebo, resting heart rate was significantly increased by doxazosin (+25%, P < 0.05) but not by urapidil (+12%, n.s.). Resting heart rate with doxazosin was significantly higher than with urapidil (P < 0.05). Similarly, the rate pressure product (RPP) at rest was increased by doxazosin (+17%, P < 0.05) but not by urapidil (+6%, n.s.).

CONCLUSIONS

We conclude that the increase in heart rate caused by urapidil is less pronounced than that with doxazosin, a property that might favour urapidil in the treatment of arterial hypertension. In addition, only doxazosin (but not urapidil) increased the RPP at rest, a finding that might be helpful to explain why this drug was never shown to improve outcome in the treatment of arterial hypertension.

Antihypertensive therapy in patients with pre-eclampsia: A prospective randomised multicentre study comparing dihydralazine with urapidil

BACKGROUND

Drug treatment is imperative for pregnant women with pregnancy-induced hypertension (PIH) and pre-eclampsia. For more than 40 years, dihydralazine has been the drug of choice for this indication. Another particularly effective and better tolerable antihypertensive is urapidil. Yet only a few studies on limited patient collectives have been published on the clinical experience with urapidil in PIH.

METHODS

Urapidil was interindividually compared to dihydralazine in a total of 42 patients, at six participating clinical centres. Patients were randomly assigned to the treatment groups. Urapidil was administered at an initial dose of 12.5-25mg, dihydralazine was administered at a uniform initial dose of 5mg. Patients were closely monitored for the initial 24h of therapy. Until delivery and in the postpartal phase, mother and baby underwent four additional follow-up checks at regular intervals.

RESULTS

Either drug was effective in lowering BP. Urapidil treatment proved to be better controllable. There were clear differences as to tolerability. In the urapidil group, one patient complained of headaches. In the dihydralazine group, six patients experienced adverse occurrences. Under dihydralazine treatment, some marked HR increases occurred, interpretable as reflectory tachycardia.

CONCLUSIONS

Urapidil proved to be equally effective as dihydralazine in lowering BP in patients with pre-eclampsia, but showed a better controllability and tolerability. Urapidil can hence be recommended as a promising alternative for patients with PIH.

The naturally occurring Arg219Leu variant of the human 5-HT1A receptor: impairment of signal transduction

The present study in transfected HEK293 cells aimed to investigate whether the pharmacological and/or transductional properties of the naturally occurring Arg219Leu variant (VAR) in the third intracellular loop of the h5-HT1A receptor differ from those of the wild-type receptor. Binding of [3H]8-hydroxy-2-(di-n-propylamino)tetraline ([H]8-OH-DPAT) and of [35S]GTPgammaS to membranes, as well as inhibition of forskolin-stimulated [3H]cAMP formation by 5-HT receptor agonists in whole cells, were estimated. The VAR and wild-type h5-HT1A receptors were found to be expressed at virtually identical densities. The VAR and wild-type receptors did also not differ with respect to the potencies of 5-HT receptor agonists and antagonists in inhibiting [3H]8-OH-DPAT binding. The ability of 5-HT to stimulate [35S]GTPgammaS binding (a measure of G protein coupling) to the VAR receptor and of the agonists 5-HT, buspirone and urapidil to inhibit forskolin-stimulated cAMP accumulation in HEK293 cells expressing the VAR receptor was decreased by 60-90%. In conclusion, the Arg219Leu variation of the human 5-HT1A receptor does not change the binding properties, but is associated with a drastic impairment of signal transduction. In patients carrying this variation, disturbances of 5-HT1A receptor-mediated functions and diminished responses to drugs acting via this receptor may occur.

Effects of perioperative alpha1 block on haemodynamic control during laparoscopic surgery for phaeochromocytoma

BACKGROUND

Laparoscopic surgery for phaeochromocytoma can cause excessive catechol amine release with severe hypertension and sinus tachycardia. i.v. calcium antagonists may be used to prevent increases in blood pressure during phaeochromocytoma resection. We investigated the effects of perioperative alpha(1) adrenergic block with urapidil on intraoperative haemodynamic events. The aim was to block the alpha(1) adrenergic receptors before any acute catecholamine release, to prevent any severe rise in blood pressure.

METHODS

Eighteen patients with a phaeochromocytoma received a continuous i.v. infusion of urapidil 10-15 mg h(-1) for 3 days before surgery and until the adrenal gland had been removed. Plasma catecholamine concentrations were measured before surgery, after induction of anaesthesia, at the end of pneumoperitoneal insufflation, during gland manipulation, after gland resection, and in the recovery room after extubation. Arterial pressure was recorded concomitantly. Hypertensive events were treated with boluses of nicardipine with or without esmolol.

RESULTS

All patients had the adrenal tumour removed without any severe rise in blood pressure or other complication. Creation of a pneumoperitoneum and adrenal gland manipulation induced significant catecholamine release associated with hypertension in 6 and 12 patients, respectively. No correlation was found between hypertensive events and plasma catecholamine levels suggesting alpha(1) receptor block with urapidil is efficacious.

CONCLUSIONS

Perioperative alpha(1) block using i.v. urapidil is a safe and efficient alternative during surgical management of phaeochromocytoma.

Synthesis of 1-substituted-6-methyluracils

A series of 6-methyl-1H-pyrimidin-2,4-diones bearing different substituents in the 1-position of the uracil ring were prepared starting from substituted ureas and diketene.

The effect of exogenous epinephrine on the incidence of hypotensive/bradycardic events during shoulder surgery in the sitting position during interscalene block

Sudden hypotensive and/or bradycardic events (HBE) have been reported in 13%-28% of patients undergoing shoulder surgery in the sitting position during interscalene block. The Bezold-Jarisch reflex is the most likely mechanism for these events. It has been hypothesized that exogenous epinephrine might be a key component to the occurrence of HBE. We conducted this prospective, randomized study to verify this hypothesis. Patients received a local anesthetic solution with (Group E; n = 55) or without (Group P; n = 55) epinephrine for interscalene block; no further exogenous epinephrine was administered. Blood pressure control was achieved with IV urapidil, a peripheral vasodilator, as needed. The incidence of HBE was 11% in Group P versus 29% in Group E (P = 0.015). Increased intraoperative heart rate and arterial blood pressure were recorded in Group E (P = 0.000). Urapidil was administered to 13% of Group P and to 31% of Group E patients (P = 0.018). Urapidil administration induced a HBE in 4% of Group P and in 5% of Group E patients. We conclude that exogenous epinephrine is involved in the development of HBE in this setting.

IMPLICATIONS

Sudden hypotensive and/or bradycardic events occur during shoulder surgery in the sitting position during interscalene block. In this study, we demonstrated that the presence of epinephrine in the local anesthetic mixture significantly increases the incidence of these events.

[Laparoscopic adrenalectomy for pheochromocytoma. Perioperative blockade with urapidil]

OBJECTIVE

To investigate the effects of coeliosurgery by catecholamine assays and the use of urapidil in the management of phaeochromocytoma.

STUDY DESIGN

Prospective cohort study.

PATIENTS

Nine consecutive patients from April 1997 to April 2001.

METHODS

Urapidil (250 mg.j-1) was administered by continuous intravenous infusion three days before surgery and continued throughout anaesthesia. Plasma catecholamine concentrations were measured before surgery, after induction of anaesthesia, during insufflation, after adrenalectomy and in the recovery room. Haemodynamic disorders were treated by nicardipine +/- esmolol bolus doses.

RESULTS

Creation of pneumoperitoneum and adrenal gland manipulations resulted in significant catecholamine releases associated with hypertension in five and eight patients respectively. Preventive urapidil use enabled easy control of blood pressure variations by additive antihypertensive drugs.

CONCLUSION

Perioperative alpha 1 blockade by urapidil enables an effective and easy control of acute preoperative haemodynamic changes.

The effects of urapidil on thermoregulatory thresholds in volunteers

In a previous study we have shown that the antihypertensive drug, urapidil, stops postanesthetic shivering. One possible mechanism in the inhibition of postanesthetic shivering by urapidil may be alterations in thermoregulatory thresholds. We therefore studied the effects of urapidil on vasoconstriction and shivering thresholds during cold-induced shivering in volunteers. Seven healthy male volunteers were cooled by an infusion of saline at 4 degrees C on two study days separated by 48 h. Thermoregulatory vasoconstriction was estimated using forearm minus fingertip skin-temperature gradients, and values exceeding 0 degrees C were considered to represent significant vasoconstriction. The rectal core temperatures at the beginning of shivering and at vasoconstriction were considered the thermoregulatory thresholds. Before cooling, either 25 mg of urapidil or placebo was administered randomly and blindly to each volunteer. When shivering occurred continuously for 10 min, another 25 mg of urapidil was administered IV to completely stop shivering. Urapidil led to a decrease in core temperature at vasoconstriction and shivering threshold by 0.4 degrees C plus/minus 0.2 degrees C (P < 0.001) and 0.5 degrees C plus/minus 0.3 degrees C (P < 0.01), respectively. Oxygen consumption increased during shivering by 70% plus/minus 30% (P < 0.01) in comparison with baseline and decreased levels after shivering stopped, despite the continued low core temperature. Our investigation shows that urapidil stops postanesthetic shivering by decreasing important thermoregulatory thresholds. This means that shivering, not hypothermia, is treated, and hypothermia will need more attention in the postanesthesia care unit.

IMPLICATIONS

In this study we show that the antihypertensive drug urapidil stops cold-induced shivering and decreases normal thermoregulatory responses, i.e., the thresholds for vasoconstriction and shivering, in awake volunteers.

Urapidil reduces elevated pulmonary vascular resistance in patients before heart transplantation

BACKGROUND

Elevated pulmonary vascular resistance is a major limitation for heart transplantation. Urapidil is a centrally and peripherally acting anti-hypertensive drug, able to decrease elevated pulmonary vascular resistance in patients with either chronic obstructive pulmonary disease or heart failure. Urapidil is available as an oral or intravenous drug. In this study, we evaluated the possible beneficial effects of intravenous urapidil in patients with reversible, elevated pulmonary vascular resistance who were scheduled for heart transplantation.

METHODS

After approval by the Ethics Committee and written consent, 22 consecutive patients with end-stage heart failure and history of pulmonary vascular resistance >3 Wood units were enrolled into an open, prospective study. Using a (right ventricular ejection fraction) REF-Swan-Ganz catheter, hemodynamics were determined during administration of nitric oxide, and before and after 3 repeated intravenous applications of 10 mg urapidil. The treatment goal was reduction of pulmonary vascular resistance by at least 30%.

RESULTS

Twenty-two patients were included to obtain complete data for 14 patients. Eight patients were not treated with urapidil: 7 patients had normal pulmonary vascular resistance at baseline, and 1 patient experienced moderate pulmonary edema before the study began. Two patients did not reach the treatment goal. In patients who responded to urapidil, the following hemodynamic changes were observed: decreased pulmonary vascular resistance (-48%), decreased transpulmonary gradient (20.0 to 13.7 mm Hg), decreased mean pulmonary arterial pressure (40 to 31 mm Hg), decreased systemic vascular resistance (-27%), mean arterial pressure (80 to 72 mm Hg), and increased right heart ejection fraction (21% to 27%). Heart rate remained unchanged.

CONCLUSIONS

Intravenous urapidil lowered elevated pulmonary vascular resistance in patients before heart transplantation. In comparison with other vasodilative drugs, the major benefit of urapidil is its oral formulation.

The pharmacologic treatment of uncomplicated arterial hypertension in patients with airway dysfunction

Because many antihypertensive drugs can affect airway function, the treatment of hypertension in patients with airway dysfunction is complex. For example, the worsening or precipitation of asthma by beta-adrenoceptor antagonists is well-recognized, but beta(1)-adrenoceptor blockers that exert mild beta(2)-agonist effects, and those that modulate the endogenous production of nitric oxide, affect airway function to a lesser extent. Therapy with selective alpha(1)-blockers is not contraindicated in cases of chronic airway obstruction. Conversely, alpha(2)-agonists must not be given to asthmatic subjects because they can adversely affect the bronchi. Calcium channel blockers do not exert severe side effects on the airways. Angiotensin-converting enzyme inhibitors may cause cough and exacerbate or even induce asthma; however, angiotensin II type I (AT(1)) antagonists do not cause cough. 5-Hydroxytryptamine modifiers such as urapidil are a treatment option for patients with chronic airway obstruction. In patients with airway dysfunction, we suggest treatment with thiazide diuretics as the initial drug choice, and calcium channel blockers if the response is poor. In the case of no response, calcium channel blockers alone must be used. However, there is no strict rule because individual patients may respond differently to individual drugs and drug combinations. Consequently, it is important to adopt a flexible approach. For patients who are unresponsive to the aforementioned drugs, AT(1) receptor antagonists, newer beta(1)-adrenoceptor-blocking agents with ancillary properties (eg, celiprolol or nebivolol), and/or vasodilators can be considered.

Effectiveness and safety of prehospital urapidil for hypertensive emergencies

The objective was to evaluate both the effectiveness and safety of urapidil in management of hypertensive emergencies (HE) in the prehospital setting. This was an open, prospective study for 6 months. We evaluated systolic (SBP), diastolic (DBP), and mean blood pressure (MBP), and heart rate (HR) with continuous noninvasive hemodynamic monitoring in 16 consecutive cases of HE. We used urapidil at different doses (25 to 100 mg) at 5 minute intervals, according to the blood pressure response. The basal DBP was 127 +/- 16 mmHg. Urapidil was effective in 15 patients. ANOVA test showed a significant drop out in DBP (P <.0001) and HR (P <.004). The highest decrease was obtained in the first 10 minutes. The decrease in DBP and HR values were significant at 5 minutes versus basal (P <.05) and at 10 versus 5 minutes (P <.01). All adverse effects had little relevance. Urapidil is effective and safe in management of HE when used by a medical team in the prehospital setting.

Renal haemodynamics and sodium excretory capacity during urapidil treatment in patients with essential hypertension

OBJECTIVE

Since renal sympathetic nerves are involved in the regulation of sodium excretion, we investigated whether treatment with urapidil, an alpha1-adrenoceptor blocking agent which also lowers sympathetic activity, alters sodium excretory capacity in patients with essential hypertension.

DESIGN

A double-blind, randomized, parallel-group study.

METHODS

Studies were carried out in 26 patients who were randomized to treatment with either placebo or urapidil for 8 weeks. Before and after treatment blood pressure, renal haemodynamics and various neurohormones were measured, as well as the response of these variables to a hypertonic saline infusion.

RESULTS

Urapidil had no effect on renal haemodynamics or neurohormones at rest However, as compared to placebo the saline-induced rises in renal plasma flow and glomerular filtration rate lasted longer during treatment with urapidil. Responses of renin, angiotensin II and catecholamines were not modified by urapidil. On the other hand, aldosterone was less suppressed while atrial natriuretic peptide was less stimulated following the saline load when patients had been treated with urapidil. Cumulative sodium excretion during a 3 h period from the moment of saline infusion was similar whether patients had been treated with placebo or with urapidil.

CONCLUSIONS

Our data show that urapidil interferes with renal haemodynamics after sodium loading but that any tendency to promote sodium output may be offset by changes in aldosterone and atrial natriuretic peptide. We conclude that urapidil, under the circumstances tested, does not affect the sodium excretory capacity of the kidney.