RESUMEN

Serum uric acid (UA) level has been proven to be related to several cardiovascular and metabolic diseases. In the present study, we examined if baseline serum UA level could predict the therapeutic efficacy of midodrine hydrochloride on vasovagal syncope (VVS) in children. The pediatric VVS patients who received midodrine hydrochloride from November 2008 to October 2022 were enrolled. After a median treatment duration of 3 months, the therapeutic effect was evaluated. According to the patients' responses to midodrine hydrochloride, which was determined by the recurrence of syncope, they were divided into effective and ineffective groups. The baseline variables were explored using univariable and multivariate logistic analysis. The predictive efficacy was assessed by receiver operating characteristic curve (ROC), precision-recall curve (PR), Hosmer-Lemeshow test, calibration curve, and decision curve analysis (DCA). Totally, 53 participants were included in the study. Among the 51 patients who were successfully followed up, 29 (56.9%) responded to midodrine hydrochloride (effective group), and the other 22 (43.1%) failed to respond to midodrine hydrochloride (ineffective group). The participants in effective group had lower baseline serum UA level than those in ineffective group (276.5 ± 73 µmol/L vs. 332.7 ± 56 µmol/L, p = 0.004). Multivariable logistic analysis showed that serum UA was associated with the therapeutic response (odds ratio (OR): 0.985, 95% confidence interval (CI): 0.974-0.997, p = 0.01). ROC analysis indicated that using baseline serum UA < 299 µmol/L as a threshold value yielded a sensitivity of 77.3% and a specificity of 79.3% in predicting the treatment response to midodrine hydrochloride. The area under the PR curve was 0.833. Hosmer-Lemeshow test yielded a p value of 0.58, and calibration plot indicated that the model was well-fitted. DCA demonstrated that treatment decision depending on the baseline serum UA level resulted in a favorable net benefit.   Conclusion: This pilot study suggested that the baseline serum UA level could be taken as a predictor of therapeutic effect of midodrine hydrochloride on VVS in children. What is Known: • Empirical and unselected use of midodrine hydrochloride has an unfavorable therapeutic effect on VVS in children. Serum uric acid (UA) is closely linked to cardiovascular events. What is New: • A low baseline serum UA level successfully predicts the therapeutic effectiveness of midodrine hydrochloride on VVS in children.

Asunto(s)

Midodrina , Síncope Vasovagal , Humanos , Niño , Midodrina/uso terapéutico , Ácido Úrico , Proyectos Piloto , Síncope Vasovagal/tratamiento farmacológico , Curva ROC

RESUMEN

Background: Paracentesis-induced circulatory disturbance (PICD) occurs in 12-20% of patients receiving human albumin for large-volume paracentesis, and can occur at lower than five liter paracentesis in acute-on-chronic liver failure (ACLF). Albumin infusions are associated with higher costs and more prolonged daycare admissions. The aim of the study was to determine if oral midodrine-hydrochloride can prevent PICD in these patients by increasing the mean arterial pressure (MAP). Methods: This open-labeled randomized controlled trial included ACLF patients undergoing paracentesis between 3 and 5 L, who were randomized to receive either 20% human albumin or midodrine hydrochloride 7.5 mg thrice daily for three days, 2 h before paracentesis. MAP was recorded daily. The primary outcome was the plasma renin activity (PRA) on day six, and a 50% increase from baseline was considered PICD. Results: 183 consecutive patients of ACLF were screened, and 50 patients were randomized to either arms. Alcohol was the most common underlying cause of cirrhosis. On day 6, PRA was non-significantly (P = 0.056) higher in the midodrine group. The absolute change of PRA between the two groups was not significant (P = 0.093). Four (16%) patients in the albumin group and five (20%) in the midodrine group developed PICD. MAP increase was not different between the albumin and midodrine arms (P = 0.851). Midodrine was found to be more cost-effective. Conclusions: Three days of oral midodrine is as effective as a human-albumin infusion in preventing PICD in ACLF patients undergoing paracentesis lesser than that done in large volume paracentesis.

RESUMEN

There are no specific and sensitive biomarkers for arteritis, and the occurrence of arteritis in nonclinical toxicological studies of a candidate drug makes development of the drug very difficult. However, we showed in a previous study that the high signal intensity region around the artery on magnetic resonance imaging (MRI) could be a candidate biomarker for detection of arteritis. The present study was conducted to clarify the details of midodrine hydrochloride (MH)-induced arteritis lesions and whether arteritis induced by a mechanism other than the vasodilatory effect, which was evaluated in a previous study, could be detected by MRI. MH is a selective peripherally acting alpha-1 adrenergic receptor agonist, known to induce arteritis due to its vasoconstrictor action, but there is not enough information about MH-induced arteritis. Based on the data obtained under multiple dosing conditions, MH was administered subcutaneously to each rat once daily for 2 days at a dose level of 40 mg/kg/day for MRI assessment. The mesenteric arteries were examined using in vivo MRI at 1 day or 7 days after administration of the final dose and examined histopathologically. On the day after the final dose, high signal intensity region around the artery was observed in animals with minimal perivascular lesions confirmed by histopathology and not observed in an animal without histological changes. On the 7th day after the final dose, no abnormality was observed in histopathological examinations and no high signal intensity regions were observed by MRI in any animal. In conclusion, although further investigation is needed to confirm that high signal intensity is a reliable biomarker for humans, it is suggested that high signal intensity around the artery could be a versatile candidate biomarker with high specificity and sensitivity.

RESUMEN

The vasoconstriction agent midodrine hydrochloride is a vital treatment for pediatric patients diagnosed with vasovagal syncope (VVS), although the efficacy is variable. This study was designed to explore the value of calcitonin gene-related peptide (CGRP) in predicting the effect of midodrine hydrochloride treatment upon VVS patients. In total, 55 children diagnosed with VVS were treated with midodrine hydrochloride for 3 months. Therapeutic response was evaluated using a symptom score system. CGRP levels were significantly higher in VVS patients (68.700 ± 6.460) than in control subjects (43.400 ± 5.810; t = 18.207, P < 0.001) and symptom scores correlated positively with CGRP concentrations (r = 0.779, P < 0.001). Patients treated with midodrine hydrochloride showed a significant reduction in symptom scores [4 (0, 6.5) vs. 1 (1, 2); z = -6.481; P < 0.001]. However, the value of plasma CGRP were potently elevated in the positive-response subjects than in the negative-response subjects (70.080 ± 5.040) vs. (61.150 ± 3.090); t = 5.817; P < 0.001). The area under the ROC curve showed that the value of CGRP for predicting the therapeutic response to midodrine hydrochloride was 0.946 (95% CI: 0.879-0.997, P < 0.001). With high sensitivity (97.7%) and specificity (83.3%), CGRP predicted the therapeutic response to midodrine hydrochloride (cut-off value, 62.56 pg/ml). In conclusion, CGRP can be used to predict the effect of midodrine hydrochloride administration in VVS patients.

RESUMEN

A new and valid method was developed for the quantitative voltammetric analysis of midodrine hydrochloride (MID) in pharmaceutical tablets (Midodrine) and biological samples. The method is based on electro-oxidation of MID supported by both disposable pencil electrode (PE) and glassy carbon electrode (GCE). The analysis was carried out using cyclic voltammetry, differential pulse voltammetry (DPV), and square wave voltammetry (SWV) techniques. The proposed analytical method was validated according to ICH guidelines. MID was successively assayed at concentration ranges of 1.15-6.55 and 0.58-3.05 µg mL-1 at PE. Also, MID was successively assayed at concentration ranges of 1.15-5.28 and 2.86-27.6 µg mL-1 at GCE for DPV and SWV methods, respectively. The proposed method was successfully used for the analysis of MID in its dosage form and human urine with good recoveries of 99.66 ± 0.33, 99.8 ± 0.45 at PE and 99.8 ± 0.25, 98.7 ± 1.27 at GCE for the DPV and SWV methods, respectively. The suggested method could be applied to the studied drug in the quality control lab as well as in its pharmacokinetic studies.

RESUMEN

A new sensitive spectrofluorimetric technique has been established for the estimation of midodrine hydrochloride. This method depends on the condensation reaction of ortho-phthalaldehyde with the primary aliphatic amine of midodrine in the presence of 2-mercapto-ethanol. The pH of the medium was adjusted to 9.0 using 0.1 M borate buffer. The fluorescence of the product was measured at wavelength of 451 nm after excitation at 334 nm. The method was rectilinear over a concentrations range of 0.1 to 1.5 µg mL-1. The lower detection and quantitation limits were 31 and 94 ng mL-1, respectively. The method was investigated following the guidelines of the International Council of Harmonization. Analysis of commercial tablet dosage form was carried out successfully by the current method with excellent recovery percentages and with no influence from coexisted pharmaceutical additives .This method was used to evaluate the uniformity of the contents of commercial tablets according to the United States Pharmacopoeia.

Asunto(s)

Midodrina , Bioensayo , Indicadores y Reactivos , Midodrina/análisis , Espectrometría de Fluorescencia/métodos , Comprimidos/análisis

RESUMEN

Enantiomeric resolution of the drug and complete separation from its degradation products was successfully achieved on a PAK IG-3 (150 × 4.6 mm i.d., 3 µm particle size) column, using UV detector at a wavelength of 290 nm, with mobile phase consisting of acetonitrile, 20 mM ammonium bicarbonate at the ratio of 95:05 (v/v), and a flow rate of 0.7 mL/min. In order to subjected to stress conditions, the drug has been exposed to alkaline, acidic, neutral, oxidative, and photolytic conditions. The products of degradation were well resolved from the main peak and proved the method's stability-indicating method. The method linear ranged between 10-110 µg/mL and 5-100 µg/mL for (+) and (-) midodrine enantiomers and regression analysis showed a correlation coefficient value (r2) of 0.999. The recovery of the method was found to be in the range of 99.1-101.2%. The detection limit for the (+) and (-) enantiomers was found to be 4 µg/mL and 1 µg/mL, respectively. The HPLC method was validated as per ICH guidelines with respect to specificity, precision, linearity, and robustness.

Asunto(s)

Midodrina , Cromatografía Líquida de Alta Presión , Estabilidad de Medicamentos , Reproducibilidad de los Resultados , Estereoisomerismo

RESUMEN

A novel, simple, sensitive method was developed for determining midodrine spectrofluorimetrically in both its raw pure form and its tablet form. This study is based on the native fluorescence of midodrine and discusses the optimum solvent used and the wavelength range. The presented method was then validated with respect to linearity, accuracy, precision, and limits of detection and quantitation. The constructed calibration curve showed a linear range of 0.1-2.0 µg/ml. The limit of detection and limit of quantitation values were 0.03 and 0.10 µg/ml respectively. Finally, content uniformity testing was applied according to the United States Pharmacopoeia by adapting the presented method.

Asunto(s)

Midodrina/análisis , Calibración , Composición de Medicamentos , Fluorescencia , Espectrometría de Fluorescencia , Comprimidos/análisis

RESUMEN

A novel sensitive and simple spectrofluorimetric method was developed then validated for determination of midodrine in both its authentic pure form and its tablets. This method is based on the reaction between midodrine's aliphatic primary amine moiety with fluorescamine reagent, using borate buffer at pH 7.8 and yielding a highly fluorescent product whose fluorescence intensity was measured at 462 nm after excitation at 388 nm. This method represents the first attempt for determination of midodrine spectrofluorimetrically. A calibration curve was constructed showing that the linear range was 0.2-3.0 µg/ml. The limit of detection and limit of quantitation values were 0.06 and 0.19 µg/ml respectively. The correlation coefficient (r) and the determination coefficient (r2 ) values were 0.9992 and 0.9984 respectively. The proposed method was validated according to ICH guidelines and successfully applied for determination of midodrine in its tablets with an overall % recovery of 99.56 ± 0.95. Finally, the presented method was adapted to study the content uniformity test according to United States Pharmacopeia guidelines.

Asunto(s)

Fluorescamina/química , Midodrina/análisis , Espectrometría de Fluorescencia/métodos , Tampones (Química) , Calibración , Concentración de Iones de Hidrógeno , Indicadores y Reactivos/química , Límite de Detección , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Solventes/química , Comprimidos/análisis , Factores de Tiempo

RESUMEN

Objective To investigate the influence of low calcium dialysate (DCa1.25) and midodrine hydrochloric (MHC) on blood pressure in hemodialysis patients. Methods Dialysate calcium concentration was changed from 1.5% (DCa1.5) to 1.25% in patients with hypercalcaemia pre- or post-dialysis.For patients with intradialytic hypotension(IDH), pre-dialysis antihypertensive drugs were ceased.If that didn′t work, MHC 2.5 or 5 mg was administered to them 30 minutes before dialysis were ceased.MHC was also administered to patients who had not taken antihypertensive drugs. The blood pressure (BP) and blood volume were recorded during dialysis. UCG and autonomic nerves function test including BP supine and standing test and sustained hand-grip test were measured as well. Results Twenty-one hemodialysis patients were involved in this study including male 9 and female 12. The average age was (54.4?14.2) years old,the time on dialysis (33.04?30.1) months. When DCa1.5 was changed to DCa1.25, 9 cases (42.9%) could maintain stable BP, but IDH occurred in 10 patients(47.6%) with symptoms such as swirl,sweat or cramp, one with lower extremities cramp and one with heart discomfort but without IDH. Patients with IDH had higher proportion of abnormal BP supine and standing tests compared with patients without IDH(50% vs. 0%, P