RESUMO

BACKGROUND: Respiratory responses to extubation can cause serious postoperative complications. Beta-blockers, such as metoprolol, can interfere with the cough pathway. However, whether metoprolol can effectively control respiratory reflexes during extubation remains unclear. The objective of this study is to evaluate the efficacy of intravenous metoprolol in attenuating respiratory responses to tracheal extubation. METHODS: Randomized, double-blinded, placebo-controlled trial. SETTING: Tertiary referral center located in Brasília, Brazil. Recruitment: June 2021 to December 2021. SAMPLE: 222 patients of both sexes with an American Society of Anesthesiologists (ASA) physical status I-III aged 18-80 years. Patients were randomly assigned to receive intravenous metoprolol 5 mg IV or placebo at the end of surgery. The primary outcome was the proportion of patients who developed bucking secondary to endotracheal tube stimulation of the tracheal mucosa during extubation. Secondary outcomes included coughing, bronchospasm, laryngospasm, Mean Blood Pressure (MAP), and Heart Rate (HR) levels. RESULTS: Two hundred and seven participants were included in the final analysis: 102 in the metoprolol group and 105 in the placebo group. Patients who received metoprolol had a significantly lower risk of bucking (43.1% vs. 64.8%, Relative Risk [RR = 0.66], 95% Confidence Interval [95% CI 0.51-0.87], p = 0.003). In the metoprolol group, 6 (5.9%) patients had moderate/severe coughing compared with 33 (31.4%) in the placebo group (RR = 0.19; 95% CI 0.08-0.43, p < 0.001). CONCLUSION: Metoprolol reduced the risk of bucking at extubation in patients undergoing general anesthesia compared to placebo.

Assuntos

RESUMO

Abstract Background: Respiratory responses to extubation can cause serious postoperative complications. Beta-blockers, such as metoprolol, can interfere with the cough pathway. However, whether metoprolol can effectively control respiratory reflexes during extubation remains unclear. The objective of this study is to evaluate the efficacy of intravenous metoprolol in attenuating respiratory responses to tracheal extubation. Methods: Randomized, double-blinded, placebo-controlled trial. Setting: Tertiary referral center located in Brasília, Brazil. Recruitment: June 2021 to December 2021. Sample: 222 patients of both sexes with an American Society of Anesthesiologists (ASA) physical status I-III aged 18-80 years. Patients were randomly assigned to receive intravenous metoprolol 5 mg IV or placebo at the end of surgery. The primary outcome was the proportion of patients who developed bucking secondary to endotracheal tube stimulation of the tracheal mucosa during extubation. Secondary outcomes included coughing, bronchospasm, laryngospasm, Mean Blood Pressure (MAP), and Heart Rate (HR) levels. Results: Two hundred and seven participants were included in the final analysis: 102 in the metoprolol group and 105 in the placebo group. Patients who received metoprolol had a significantly lower risk of bucking (43.1% vs. 64.8%, Relative Risk [RR = 0.66], 95% Confidence Interval [95% CI 0.51-0.87], p = 0.003). In the metoprolol group, 6 (5.9%) patients had moderate/severe coughing compared with 33 (31.4%) in the placebo group (RR = 0.19; 95% CI 0.08-0.43, p < 0.001). Conclusion: Metoprolol reduced the risk of bucking at extubation in patients undergoing general anesthesia compared to placebo.

RESUMO

ABSTRACT Herein, we examined the protective effect of metoprolol combined with atractylenolide I (Atr I) in acute myocardial infarction (AMI) by regulating the SIRT3 (silent information regulator 3)/ß-catenin/peroxisome proliferator-activated receptor gamma (PPAR-γ) signaling pathway. Briefly, 50 rats were randomly divided into the sham operation, model, metoprolol, Atr I, and combination metoprolol with Atr I groups (combined treatment group). The AMI model was established by ligating the left anterior descending coronary artery. After treatment, infarct size, histopathological changes, and cell apoptosis were examined using 2,3,5-triphenyltetrazolium chloride staining, hematoxylin-eosin staining, and the TUNEL assay. The left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), and left ventricular mass index (LVMI) were detected by echocardiography. Endothelin-1 (ET-1), nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) levels were detected using enzyme-linked immunosorbent assays. Furthermore, we measured lactate dehydrogenase (LDH), creatine kinase (CK) isoenzyme (CK-MB), and CK levels. Western blotting was performed to determine the expression of SIRT3, ß-catenin, and PPAR-γ. Herein, the combined treatment group exhibited increased levels of LVEF, LVFS, and NO, whereas LVMI, ET-1, TNF-α, IL-6, LDH, CK-MB, and CK levels were decreased. Importantly, the underlying mechanism may afford protection against AMI by increasing the expression levels of SIRT3, ß-catenin, and PPAR-γ

Assuntos

RESUMO

ABSTRACT Introduction: Classic coronary artery bypass grafting (CABG) surgery involves diastolic cardiac arrest under cardiopulmonary bypass, while off-pump CABG (OPCABG) has become widespread in recent years. Methods: 174 patients who underwent OPCABG were included in the study. Patients were divided into two groups. Group I (n=90) received ivabradine and Group M (n=84) received metoprolol before surgery until postoperative day 10. Intraoperative arrhythmias and hypotension were recorded. Postoperative atrial fibrillation (AF) and arrhythmia, mortality and morbidity rates were assessed based on the 30-day postoperative follow-up. Results: There were no significant differences in the intraoperative amount of inotropic support and red blood cell transfusion between groups (P=0.87 and P=0.31). However, the rates of intraoperative arrhythmias and hypotension were not significantly higher in Group M (P=0.317 and P=0.47). Ventricular tachycardia/ventricular fibrillation (VT/VF) was observed in 2 patients in both groups. Postoperative AF occurred in 7 patients (7.7%) in Group I and in 10 patients (11.9%) in Group M. Although there was a trend towards a higher prevalence of AF in Group M patients, this did not reach statistical significance. In addition, mortality and morbidity rates were comparable between groups.

RESUMO

PURPOSE: To investigate ocular safety of intravitreal metoprolol in eyes with central serous chorioretinopathy. METHODS: Five eyes of five patients diagnosed with chronic central serous chorioretinopathy (cCSC) previously treated unsuccessfully with oral spironolactone, micropulse laser and intravitreal anti-vascular endothelial growth factor agents were enrolled and received off-label intravitreal metoprolol (50 µg/0.05 ml). Baseline and follow-up examinations included measurement of best-corrected visual acuity (BCVA), intraocular pressure, anterior chamber cellular/flare scores, vitritis classification, fluorescein and indocyanine green angiography, spectral domain optical coherence tomography and electroretinography (ERG), recorded by means of DTL electrodes and following the standard suggested by the International Society for Clinical Electrophysiology of Vision (ISCEV). The total follow-up period was 4 weeks. RESULTS: There were no significant differences between baseline and follow-up ERG parameters: scotopic or photopic, a- and b-wave amplitude and implicit time, nor oscillatory potentials amplitude, or whatsoever. No intraocular inflammation sign was observed. In addition, BCVA showed small improvement in 4 or kept baseline values in 1 patient. The subretinal and/or intraretinal fluid volume reduced in all patients at 1 month after treatment. CONCLUSION: Patients with refractory cCSC treated with intravitreal 50 µg/0.05 ml metoprolol showed no signs of acute ocular toxicity, along with intraretinal fluid reduction and slight BCVA improvement 1 month after injection. This data suggest that intravitreal metoprolol may be a safe alternative for cCSC.

Assuntos

RESUMO

The development of extended-release dosage forms with adequate drug release is a challenge for pharmaceutical companies, mainly when the drug presents high solubility, as in Biopharmaceutics Classification System (BCS) class I. This study aimed to develop extended-release mini-tablets containing metoprolol succinate (MS), while integrating design of experiments (DOE) and physiologically based biopharmaceutics modeling (PBBM), to predict its absorption and to run virtual bioequivalence (VBE) studies in both fasted and fed states. Core mini-tablet formulations (F1, F2, and F3) were prepared by direct compression and coated using nine coating formulations planned using DOE, while varying the percentages of the controlled-release and the pore-forming polymers. The coated mini-tablets were submitted to a dissolution test; additional formulations were prepared that were optimized by simulating the dissolution profiles, and the best one was submitted to VBE studies using GastroPlus® software. An optimized formulation (FO) containing a mixture of immediate and extended-release mini-tablets showed to be bioequivalent to the reference drug product containing MS when running VBE studies in both fasted and fed states. The integration of DOE and PBBM showed to be an interesting approach in the development of extended-release mini-tablet formulation containing MS, and can be used to rationalize the development of dosage forms.

RESUMO

INTRODUCTION: Classic coronary artery bypass grafting (CABG) surgery involves diastolic cardiac arrest under cardiopulmonary bypass, while off-pump CABG (OPCABG) has become widespread in recent years. METHODS: 174 patients who underwent OPCABG were included in the study. Patients were divided into two groups. Group I (n=90) received ivabradine and Group M (n=84) received metoprolol before surgery until postoperative day 10. Intraoperative arrhythmias and hypotension were recorded. Postoperative atrial fibrillation (AF) and arrhythmia, mortality and morbidity rates were assessed based on the 30-day postoperative follow-up. RESULTS: There were no significant differences in the intraoperative amount of inotropic support and red blood cell transfusion between groups (P=0.87 and P=0.31). However, the rates of intraoperative arrhythmias and hypotension were not significantly higher in Group M (P=0.317 and P=0.47). Ventricular tachycardia/ventricular fibrillation (VT/VF) was observed in 2 patients in both groups. Postoperative AF occurred in 7 patients (7.7%) in Group I and in 10 patients (11.9%) in Group M. Although there was a trend towards a higher prevalence of AF in Group M patients, this did not reach statistical significance. In addition, mortality and morbidity rates were comparable between groups.

Assuntos

RESUMO

Abstract Quality is paramount and needs to be maintained throughout the shelf life of pharmaceuticals. The current study aimed to evaluate the quality, potency, and drug-drug interaction in an in vivo animal model by using two drugs, namely, metoprolol and glimepiride. Tablets were selected for their physical characteristics, such as shape, size, and color. Quality control tests, such as weight variation, hardness, friability, and disintegration tests, and invitro drug release studies were performed as per USP. Drug-drug interaction and in vivo studies were carried out according to the standard protocol of the animal ethics committee. Quality control tests of both the tablets were within the specified range. The cumulative release percentages of the drugs were 81.12% and 85.36% for Metoprolol Tartrate and Glimepiride, respectively, in a physiological buffer solution within 1 h. The combination of metoprolol and Glimepiride also significantly decreased the blood glucose level in diabetic animals. However, the blood glucose level increased in the group receiving metoprolol only, but the difference was not significant. The result suggested that the formulations are safe. However, the chronic use of this combination requires frequent monitoring of blood glucose level to improve its efficacy and for the patient's safety.

Assuntos

RESUMO

Abstract Stroke is one of the most important health concerns worldwide. Calcium ions accumulation in the nerve cells and increase in the catecholamines level of the brain following cerebral ischemia/reperfusion (I/R) are accompanied by damaging effects. Therefore, the present study aimed to evaluate the effects of diltiazem, as a calcium channel blocker, and metoprolol, as a β-adrenoceptors antagonist, on I/R injury. In this study, 30 male Wistar rats were divided into control, I/R, metoprolol, diltiazem, and metoprolol plus diltiazem groups (n=6 in each). Metoprolol (1 mg/kg/day) and diltiazem (5 mg/kg/day) were injected intraperitoneally (i.p.) for 7 days before I/R induction. On day 8, the animals underwent ischemia by bilateral common carotid arteries occlusion for 20 min. Histopathological analysis showed a significant reduction in leukocyte infiltration in diltiazem, metoprolol, and diltiazem plus metoprolol treated rats compared with the I/R group (P<0.05, P<0.01, P<0.01, respectively). In addition, in all treated groups, myeloperoxidase activity and malondialdehyde levels in the brain tissue significantly declined compared with the I/R group (P<0.001). Furthermore, pre-treatment with diltiazem and metoprolol alone or in co-administration remarkably reduced infarct size following I/R (P<0.001). Overall, the results indicate the considerable neuroprotective effects of metoprolol and diltiazem in cerebral I/R.

RESUMO

BACKGROUND: Choroidal hemangioma is a visual threatening condition for which treatments is neither uniform nor widely available. New management options are necessary. The purpose of this study is to assess the safety and early outcome of intravitreal metoprolol tartrate in five patients with CCH. METHODS: Five eyes of five patients diagnosed with subfoveal or peripapillary CCH and unsuccessfully treated with intravitreal anti-VEGF agents were enrolled and received off-label intravitreal injections of metoprolol (50µg/0.05 ml). Baseline and follow-up evaluations included best-corrected visual acuity, intraocular pressure measurement, assessment of anterior chamber cellular score/flare and vitritis, retinography, fundus autofluorescence, and ERG. Patients were followed for a period of 30 days. Statistical analysis involved comparison of pre- and post-treatment findings using a paired t-test. RESULTS: There was no significant difference in all ERG parameters regarding a- and b-wave amplitude and implicit time, and oscillatory potentials' maximal amplitude. There were no significant changes in visual acuity. None of the patients developed clinical signs of intraocular inflammation. The subretinal and/or intraretinal fluid improved in 3 out of 5 patients 4 weeks after the metoprolol injection. CONCLUSIONS: Patients with CCH treated with a single injection of 50µg/0.05ml intravitreal metoprolol injections showed no signs of acute ocular toxicity. This pilot study did not assess long-term retinal toxicity, different concentrations, drug resistance, and complications from repeated-intravitreal injections.

Assuntos

RESUMO

Resumo Fundamento Qualidade de imagem e dose de radiação são otimizadas com uma frequência cardíaca (FC) lenta e estável na realização de imagens de artérias coronárias durante a angiografia cardíaca por tomografia computadorizada (CCTA, do inglês cardiac computed tomography angiography) A segurança, a eficácia e o protocolo para a redução da FC com medicamento betabloqueador ainda não foi bem descrita em uma população de pacientes pediátricos. Objetivo Oferecer um protocolo de dose de metoprolol eficiente a ser usado em pacientes pediátricos externos durante a CCTA. Métodos Realizamos uma revisão retrospectiva de todos os pacientes pediátricos externos que receberam o metoprolol durante a CCTA. As características demográficas e clínicas foram resumidas e a redução média em FC foi estimada utilizando-se um modelo de regressão linear multivariada. As imagens foram avaliadas em uma escala de 1 a 4 (1= ideal). Resultados Um total de 78 pacientes externos passaram a uma CCTA com o uso de metoprolol. A média de idade foi de 13 anos, a média de peso foi de 46 kg, e 36 pacientes (46%) eram do sexo masculino. As doses médias de metoprolol foram 1,5 (IQR 1,1; 1,8) mg/kg, e 0,4 (IQR 0,2; 0,7) mg/kg para administrações orais e intravenosas, respectivamente. O produto dose-comprimento por exame foi de 57 (IQR 30, 119) mGy*cm. A redução média da FC foi 19 (IQR 12, 26) batimentos por minuto, ou 23%. Não foram relatadas complicações ou eventos adversos. Conclusão O uso de metoprolol num cenário de pacientes pediátricos externos para redução da FC antes de uma CCTA é seguro e eficiente. Pode-se reproduzir um protocolo de dose de metoprolol quando for necessário atingir uma FC mais lenta, garantindo tempos de aquisição mais rápidos, imagens mais claras e redução na exposição à radiação nessa população. (Arq Bras Cardiol. 2021; 116(1):100-105)

Abstract Background Image quality and radiation dose are optimized with a slow, steady heart rate (HR) when imaging the coronary arteries during cardiac computed tomography angiography (CCTA). The safety, efficacy, and protocol for HR reduction with beta blocker medication is not well described in a pediatric patient population. Objective Provide a safe and efficient metoprolol dose protocol to be used in pediatric outpatients undergoing CCTA. Methods We conducted a retrospective review of all pediatric outpatients who received metoprolol during CCTA. Demographic and clinical characteristics were summarized and the average reduction in HR was estimated using a multivariate linear regression model. Images were evaluated on a 1-4 scale (1= optimal). Results Seventy-eight pediatric outpatients underwent a CCTA scan with the use of metoprolol. The median age was 13 years, median weight of 46 kg, and 36 (46%) were male. The median doses of metoprolol were 1.5 (IQR 1.1, 1.8) mg/kg and 0.4 (IQR 0.2, 0.7) mg/kg for oral and intravenous administrations, respectively. Procedural dose-length product was 57 (IQR 30, 119) mGy*cm. The average reduction in HR was 19 (IQR 12, 26) beats per minute, or 23%. No complications or adverse events were reported. Conclusion Use of metoprolol in a pediatric outpatient setting for HR reduction prior to CCTA is safe and effective. A metoprolol dose protocol can be reproduced when a slower HR is needed, ensuring faster acquisition times, clear images, and associated reduction in radiation exposure in this population. (Arq Bras Cardiol. 2021; 116(1):100-105)

Assuntos

RESUMO

PURPOSE: To verify the safety of different doses of intravitreal metoprolol tartrate (MT) after intravitreal injection in rabbit eyes. METHODS: Animals were randomly assigned into 2 groups: group I received 50 µg of MT and group II 100 µg of MT. A volume of 0.05 mL of the drug solution was administered through an intravitreal injection, while the control eyes received an equal volume of saline solution. Safety was assessed by clinical observation, electroretinography (ERG) and histological evaluation. RESULTS: No evidence of clinical toxicity was observed. ERG waveforms from the MT treated eyes were similar to those recorded from the control eyes in dark-adapted state, amplitude and the implicit time are similar between the groups in light-adapted state, and their retinas had no signs of toxicity by histological evaluation 7 days after intravitreal injection. CONCLUSIONS: The intravitreal use of metoprolol at 50 and 100 µg dosages does not cause short-term retinal toxicity in rabbits.

Assuntos

RESUMO

OBJECTIVE: To evaluate the ability of heart rate (HR) and HR difference during head-up tilt test (HUTT) and to predict clinical improvement related to metoprolol treatment in children and adolescents with postural tachycardia syndrome (POTS). STUDY DESIGN: This was a retrospective cohort study. A total of 53 subjects (27 male, aged 6-12 years old, mean age 11.79 ± 1.50 years old) with POTS treated with metoprolol were involved from July 2012 to September 2019. In total, 52 subjects who underwent health examination during the same period were matched as the control group. Subjects in both groups underwent HUTT. The HR distance between 5 minutes and 0 minutes (HR difference 5) and between 10 minutes and 0 minutes (HR difference 10) during HUTT was calculated. RESULTS: The POTS group was significantly greater than the control group in HR 5, HR 10, HR difference 5, and HR difference 10 (P < .01). There was no statistical difference in HR 0 between the 2 groups (P > .05). In total, 53 subjects with POTS were followed up for 96.0 (IQR, 40.5, 134.5) days during treatment with metoprolol. HUTT results demonstrated that 58.49% of subjects with POTS had a response and symptom scores were reduced after intervention. HR and HR difference were useful in predicting the efficacy of metoprolol on POTS. When HR 5, HR 10, HR difference 5, and HR difference 10, respectively, were ≥110, 112, 34, and 37 beats/min, the sensitivity and specificity were 82.50% and 69.23%, 84.62% and 69.70%, 85.29% and 89.47%, and 97.56% and 64.86%, respectively. CONCLUSIONS: HR and HR difference are helpful to predict the efficacy of metoprolol on POTS in children and adolescents.

Assuntos

RESUMO

Plasma concentration data points (n = 2,640) from 16 healthy adults were used to develop and validate limited sampling strategies (LSS) for estimation of phenotypic metrics for CYP enzymes and the ABCB1 transporter, using a cocktail of subtherapeutic doses of the selective probes caffeine (CYP1A2), metoprolol (CYP2D6), midazolam (CYP3A), losartan (CYP2C9), omeprazole (CYP2C19), and fexofenadine (ABCB1). All-subsets linear regression modelling was applied to estimate the AUC0-12h for caffeine, fexofenadine, and midazolam, and the AUC0-12h ratio of metoprolol: α-OH metoprolol and omeprazole:5-OH omeprazole. LSS-derived metrics were compared with the parameters' 'best estimates' obtained by non-compartmental analysis using all plasma concentration data points. The correlation coefficient (R 2) was used to identify the LSS equations that provided the best fit for n timed plasma samples, and the jack-knife statistics was used as an additional validation procedure for the LSS models. Single time-point LSS models provided R 2 values greater than 0.95 (R 2 > 0.95) for the AUC0-12h ratio of metoprolol:α-OH metoprolol and omeprazole:5-OH omeprazole, whereas 2 time-point models were required for R 2 > 0.95 for the AUC0-12h of caffeine, fexofenadine, and midazolam. Increasing the number of sampling points to three led to minor increases in R 2 and/or the bias or prediction of the estimates. In conclusion, the LSS models provided accurate prediction of phenotypic indices for CYP1A2, CYP2C19, CYP2D6, CYP3A, and ABCB1, when using subtherapeutic doses of selective probes for these enzymes and transporter.

RESUMO

This work is the continuation of a series of studies focused on establishing the relationship between the surface thermodynamic properties of polyelectrolyte matrix tablets and drug release mechanisms. In this case, two model drugs with different polarity features, such as carbamazepine (non-polar) and metoprolol succinate (polar) were used in combination with polymeric material hydroxypropyl-methyl cellulose (HPMC) and two polyelectrolytes derived from maleic anhydride corresponding to the sodium salts of poly(maleic acid-alt-ethylene) and poly(maleic acid-alt-octadecene) named PAM-0Na and PAM-18Na, respectively. The polymers were obtained and characterized as reported previously. Surface studies were performed by the sessile drop method, whilst the surface free energy was determined through Owens, Wendt, Rable and Kaeble (OWRK) semi-empirical model. By contrast, the drug release studies were performed by in vitro dissolution tests, where data were analyzed through dissolution efficiency. The results showed that, depending on the drug polarity, type and polymer proportion, surface properties and drug release processes are significantly affected.

RESUMO

Resumen Introducción: A partir de la teoría de los sistemas dinámicos y de la teoría de la probabilidad se han desarrollado metodologías altamente sensibles de aplicación clínica que permiten diferenciar normalidad, enfermedad y evolución hacia la enfermedad cardiaca. Métodos: Se seleccionaron los registros Holter de siete casos normales y 73 con diagnóstico de arritmia con y sin tratamiento terapéutico de metoprolol. Se aplicaron medidas de probabilidad establecidas previamente para evaluar la frecuencia cardiaca máxima, mínima y promedio, así como el número de latidos por hora. Resultados: Casi la mitad de los casos con arritmias y sin tratamiento presentaron medidas matemáticas de enfermedad y de evolución hacia la enfermedad, mientras que en el grupo con tratamiento con metoprolol, tres cuartas partes cumplieron con estas características. Conclusiones: Se lograron distinciones matemáticas más objetivas entre dinámicas cardiacas tratadas con y sin metoprolol, las cuales pueden ser de gran utilidad para realizar seguimiento individual.

Abstract Introduction: Based on the theory of dynamic systems and probability theory, highly sensitive clinical methodologies have been developed to differentiate normality, disease and evolution towards cardiac disease. Methods: Holter recordings, 7 normal and 73 with arrhythmia diagnosis with and without therapeutic treatment of Metoprolol, were selected. Probability measures, established in a previous work, were applied for assessing maximum, minimal and average heart rate and beats per hour. Results: It was found that almost a half of the cases with arrhythmias without beta-blocker therapy exhibited mathematical measures of illness and evolution towards disease, whereas in the treatment group with Metoprolol, three quarters accomplished these features. Conclusions: More objective mathematical distinctions were achieved between cardiac dynamics treated with and without metoprolol, which is very useful for individual follow-up.

RESUMO

BACKGROUND: Vascular endothelial fibrinolytic function is impaired in adults with prehypertension and hypertension and plays a mechanistic role in the development of atherothrombotic events. The influence of ß-blockers on endothelial fibrinolysis is unknown. This study compared the effects of chronic nebivolol and metoprolol treatment on endothelial tissue-type plasminogen activator (t-PA) release in adults with elevated blood pressure (BP). METHODS AND RESULTS: Forty-four middle-aged adults (36% women) with elevated BP completed a 3-month, double-blind, randomized, placebo-controlled trial comparing nebivolol (5 mg/d), metoprolol succinate (100 mg/d), and placebo. Net endothelial t-PA release was determined in vivo in response to intrabrachial infusions of bradykinin and sodium nitroprusside before and after each intervention. In a subset, the dose-response curves to bradykinin and sodium nitroprusside were repeated with a coinfusion of the antioxidant vitamin C. At baseline, resting BP and endothelial t-PA release were comparable between the 3 groups. BP decreased to a similar extent (≈10 mm Hg) in the nebivolol- and metoprolol-treated groups. There was a substantial increase (≈30%; P<0.05) in the capacity of the endothelium to release t-PA following chronic treatment with nebivolol but not metoprolol or placebo. Mitigating oxidant stress with vitamin C coinfusion potentiated t-PA release (90%; P<0.05) at baseline in all groups. However, after the intervention, t-PA release was unchanged by vitamin C coinfusion in the nebivolol group only. CONCLUSIONS: Nebivolol but not metoprolol improves endothelial t-PA release in adults with elevated BP. This may be an important vascular benefit of nebivolol. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01595516.

Assuntos

RESUMO

Os sistemas multiparticulados são aqueles nos quais a dose do fármaco está dividida em pequenas unidades funcionais, tendo assim, uma série de vantagens sobre os sistemas monolíticos convencionais. Este trabalho teve por objetivo desenvolver formulações multiparticuladas de uso oral para fármacos anti-hipertensivos que serão utilizados na composição de associações. O material está dividido em seis capítulos, sendo inicialmente apresentada uma revisão da literatura a respeito da caracterização física destas pequenas unidades. Ensaios como análise granulométrica, morfologia, densidade, porosidade, avaliação de resistência mecânica e desintegração são os mais empregados para esta finalidade, possibilitando ao formulador conhecer os fatores de maior impacto relacionados às matérias primas e ao processo de fabricação no comportamento das formulações produzidas. Os demais capítulos seguem com o desenvolvimento dos sistemas multiparticulados, que foram embasados em diferentes delineamentos experimentais, seja pela utilização de planejamento fatorial fracionado ou projeto de mistura. Para o metoprolol, fármaco de alta solubilidade, foram produzidas formulações de liberação controlada, sendo a estratégia dividida em três etapas: (I) Produção de minicomprimidos revestidos, nos quais foram avaliadas diferentes combinações do polímero modulador de liberação; (II) otimização do perfil de liberação do fármaco, com avaliação de misturas das formulações produzidas na primeira etapa; (III) Processo de extrusão a quente, no qual diferentes proporções de fármaco e polímero hidrofóbico foram avaliadas. Para os fármacos hidroclorotiazida e olmesartana medoxomila, ambos de baixa solubilidade, a estratégia adotada foi a incorporação de uma dispersão dos fármacos e agentes solubilizantes em grânulos inertes obtidos por extrusão/revestimento. Adicionalmente, também foram produzidas formulações por extrusão a quente de diferentes proporções destes fármacos em polímero hidrofílico. De acordo com os resultados obtidos, foi possível obter formulações de minicomprimidos e grânulos com perfil de dissolução satisfatório, semelhantes aos apresentados pelos medicamentos adotados como referência. Em relação à extrusão a quente foi possível avaliar a influência do processo e polímeros empregados no perfil de dissolução dos grânulos produzidos

Multiparticulate systems are dosage forms in which dose is divided into small functional units presenting some advantages over monolithic conventional systems. The objective of this work was developing multiparticulate formulations for oral use containing antihypertensive drugs to be used in association. The thesis is divided into six issues, been first presented a literature review about physical characterization of multiparticulate systems. Granulometric analysis, morphology, density, porosity, mechanical strength and disintegration are the most used physical characterization tests, enabling formulator knowing the major impact factors related to raw materials and manufacturing process in the performance of the produced formulations. The other issues present the development of the multiparticulate systems based on different statistical experimental design, as fractional factorial design or mixture project. For metoprolol, a highly soluble drug, controlled release formulations were obtained, and the strategy was divided into three steps: (I) coated minitablets production, where different combinations of the controlled release polymer were analyzed; (II) drug release profile optimization, evaluating formulations mixtures produced in the first step; (III) hot melt extrusion process, where different drug: hydrophobic polymer ratios were evaluated. For hydrochlorothiazide and olmesartan medoxomil, both low soluble drugs, the strategy was incorporating a dispersion containing the drugs and solubilizing agents in inert granules obtained by extrusion/coating processes. Additionally, formulations containing different ratios of these drugs and hydrophilic polymers were produced by hot melt extrusion. According to the results, it was possible to obtain minitablets and granules with good dissolution profile, similar to the reference products. Regarding to hot melt extrusion, it was possible to evaluate the influence of process and polymers used in the dissolution profile of the produced granules

Assuntos

RESUMO

ABSTRACTBACKGROUND AND OBJECTIVES: Injection pain after propofol administration is common and maydisturb patients' comfort. The aim of this study was to compare effectiveness of intravenous(iv) nitroglycerin, lidocaine and metoprolol applied through the veins on the dorsum of hand orantecubital vein on eliminating propofol injection pain.METHOD: There were 147 patients and they were grouped according to the analgesic adminis-tered. Metoprolol (n = 31, Group M), lidocaine (n = 32, Group L) and nitroglycerin (n = 29, GroupN) were applied through iv catheter at dorsum hand vein or antecubital vein. Pain was evalu-ated by 4 point scale (0 - no pain, 1 --- light pain, 2 --- mild pain, 3 --- severe pain) in 5, 10, 15and 20th seconds. ASA, BMI, patient demographics, education level and the effect of pathwaysfor injection and location of operations were analyzed for their effect on total pain score.RESULTS: There were no differences between the groups in terms of total pain score (p = 0.981).There were no differences in terms of total pain score depending on ASA, education level,location of operation. However, lidocaine was more effective when compared with metoprolol(p = 0.015) and nitroglycerin (p = 0.001) among groups. Although neither lidocaine nor metopro-lol had any difference on pain management when applied from antecubital or dorsal hand vein(p > 0.05), nitroglycerin injection from antecubital vein had demonstrated statistically lowerpain scores (p = 0.001).CONCLUSION: We found lidocaine to be the most effective analgesic in decreasing propofolrelated pain. We therefore suggest iv lidocaine for alleviating propofol related pain at operations.

RESUMOJUSTIFICATIVA E OBJETIVOS: A dor no local da injeção após a administração de propofol é comum e pode causar desconforto nos pacientes. O objetivo deste estudo foi comparar a eficácia de nitroglicerina, lidocaína e metoprolol, aplicados intravenosamente através de veias do dorso das mãos ou antecubitais, para eliminar a dor causada pela injeção de propofol.MÉTODOS: Foram alocados em grupos 147 pacientes de acordo com o analgésico administrado: metoprolol (n = 31, Grupo M), lidocaína (n = 32, Grupo L) e nitroglicerina (n = 29, Grupo N). Os analgésicos foram aplicados via cateter intravenoso em veia do dorso da mão ou antecubital. A dor foi avaliada com uma escala de quatro pontos (0 = sem dor, 1 = dor leve, 2 = dor moderada, 3 = dor intensa) nos segundos cinco, 10, 15 e 20. Os dados demográficos dos pacientes, estado físico ASA, IMC, nível de escolaridade, efeito das vias de injeção e local das cirurgias foram analisados quanto a seus efeitos no escore total de dor.RESULTADOS: Não houve diferença entre os grupos em relação ao escore total de dor (p = 0,981). Não houve diferença no escore total de dor em relação ao estado físico ASA, escolaridade e local da cirurgia. No entanto, lidocaína foi mais eficaz em comparação com metoprolol (p = 0,015) e nitroglicerina (p = 0,001), na comparação entre os grupos. Embora lidocaína e metoprolol não tenham apresentado diferença no tratamento da dor quando aplicados em veia antecubital ou do dorso da mão (p > 0,05), a injeção de nitroglicerina em veia antecubital apresentou escores de dor estatisticamente menores (p = 0,001).CONCLUSÃO: Lidocaína mostrou-se como analgésico mais eficaz para diminuir a dor relacionada à injeção de propofol. Sugerimos, portanto, lidocaína IV para aliviar a dor relacionada à injeção de propofol em operações.

Assuntos