ECTOPIC trial: The efficacy of flEcainide Compared To metOprolol in reducing Premature ventrIcular contractions. A randomized open label cross-over study in pediatric patients.

BACKGROUND: Frequent premature ventricular contractions (PVCs) in children are usually considered benign. Symptoms and/or left ventricular dysfunction are indications for treatment with anti-arrhythmic drugs (AAD). OBJECTIVE: To evaluate the efficacy of flecainide versus metoprolol in reducing PVCs in children. METHODS: A randomized open label cross-over trial children with a PVC-burden of >15% on Holter; successively treated with metoprolol and flecainide or vice versa, with a drug free interval of at least two weeks. Holter measurements were repeated before and after the start of the AAD. RESULTS: Sixty patients were screened, 19 patients could be included. Median age was 13.9 years (IQR 5.5 years). Mean baseline PVC-burden was 21.7% (N=18, SD±14.0) before the start of flecainide and 21.2% (N=17, SD±11.5) before the start of metoprolol. In a mixed model analysis the estimated mean reduction in PVC-burden was 10.6 percentage-points (95%-CI 5.8-15.3) for flecainide and 2.4 percentage-points (95%-CI -2.7-7.5) for metoprolol, with a significant difference of 8.2 percentage-points (95%-CI of 0.86-15.46, P=0.031). Exploratory analysis revealed that 9/18 patients treated with flecainide and 1/17 patients treated with metoprolol, had a reduction to a PVC-burden below 5%. No discriminating factors between flecainide-responders and non-responders were found; the mean plasma level was not significantly different (0.34 mg/L versus 0.52 mg/L, P=0.277). CONCLUSIONS: In children with frequent PVCs flecainide led to a significant greater reduction of PVC-burden, compared to metoprolol. Flecainide was effective in only a subgroup of patients, which appears to be unrelated to the plasma level. (Dutch Trial Register number 26689).

A cross-sectional study on metoprolol concentrations in various biological samples and their inter-correlations.

BACKGROUND: Concentrations of metoprolol in exhaled breath condensate (EBC) have not been investigated. Herein, we aim to determine the metoprolol levels in EBC, plasma, and urine samples. METHODS: Biological samples were collected from 39 patients receiving metoprolol. Metoprolol was determined using liquid chromatography mass spectrometery. The obtained metoprolol levels in biological fluids were investigated for possible inter-correlations. RESULTS: Acceptable linearity was obtained with coefficient of determinations equal to 0.9998, 0.9941, and 0.9963 for EBC, plasma, and urine samples, respectively. The calibration curves were linear in the ranges of 0.6-500, 0.4-500, and 0.7-10,000 µg·L- 1 regarding EBC, plasma, and urine samples, respectively. The detection and quantification limits were (0.18, 0.12, and 0.21 µg·L- 1) and (0.60, 0.40, and 0.70 µg·L- 1) for EBC, plasma, and urine samples, respectively. The relative standard deviations for the intra- and inter-day replications were obtained between 5.2 and 6.1 and 3.3-4.6%, respectively. The obtained mean metoprolol levels in EBC, plasma, and urine samples of 39 patients were 5.35, 70.76, and 1943.1 µg·L- 1. There were correlations between daily dose and plasma and urinary concentrations of metoprolol in the investigated samples, whereas no significant correlation was observed for daily dose and EBC levels. The correlation among plasma-urine levels was significant, however, the non-significant correlation was obtained between plasma and EBC concentrations. CONCLUSION: Metoprolol levels varied widely due to the metabolic pattern of the Azeri population, different dosages received by the patients, formulation effects, age, sex, and interactions with the co-administered drugs. A poor correlation of EBC-plasma concentrations and a significant correlation of plasma-urine concentrations were observed. Further investigations are required to provide the updated services to personalized medicine departments.

[Calcium Dibutyryl Adenosine Cyclophosphate Enhances the Effect of Metoprolol in Treating Older Adults With Heart Failure Combined With Arrhythmia]. / äºŒä¸é °çŽ¯ç£·è ºè‹·é’™å¯å¢žå¼ºç¾Žæ‰˜æ´›å°”å¯¹è€å¹´å¿ƒåŠ›è¡°ç«­åˆå¹¶å¿ƒå¾‹å¤±å¸¸æ‚£è€ çš„æ²»ç–—æ•ˆæžœ.

Objective: To explore the effect and safety of calcium dibutyryl adenosine cyclophosphate (dbcAMP-Ca) combined with metoprolol in the treatment of older adults with heart failure combined with arrhythmia. Methods: A total of 102 elderly patients with heart failure combined with arrhythmia were enrolled in our hospital between February 2021 and April 2023. The list of patients enrolled was entered into a random database by independent staffs not involved in the study and random assignment sequences were generated by the SAS9.4 software. Then, the 102 elderly patients were divided into a control group ( n=51) and an experimental group ( n=51). Patients in the control group were given metoprolol at an initial dose of 6.25 mg/d, which was gradually increased to the target dose of 25 mg/d. Patients in the experimental group were given 40 mg of dbcAMP-Ca once a day via intravenous drip in addition to the treatment given to the control group. Both groups were treated for 4 weeks. The rate of effective response to clinical treatment (the number of cases achieving significant effects and those achieving some effects divided by the total number of cases in the group) was defined as the main outcome index. Secondary indexes included cardiac function, heart rate variability, exercise ability, hemorheology, myocardial injury indexes, inflammatory indexes, and the occurrence of adverse reactions. Results: The rate of effective response to clinical treatment was higher in the experimental group than that in the control group (94.12% [48/51] vs. 78.43% [40/51], P<0.05). After treatment, the left ventricular end-diastolic and end-systolic dimensions (LVEDD and LVESD) and the interventricular septal thickness (IVS) were lower in the experimental group than those in the control group, while the left ventricular ejection fraction (LVEF) and the stroke volume (SV) were higher in the experimental group than those in the control group ( P<0.05). In terms of heart rate variability after treatment, the standard deviation of all the normal-to-normal intervals/the average of all the normal-to-normal intervals (SDNN/SDANN), the percentage of NN50 in the total number of normal-to-normal intervals (PNN50%), and the root mean square of the differences between adjacent normal-to-normal intervals/root mean square differences of successive R-R intervals (RMSSD) were higher in the experimental group than those in the control group ( P<0.05). In terms of exercise capacity after treatment, the subjects in the experimental group covered more distance in the 6-min walk test than those in the control group did ( P<0.05). In terms of the hemorheology indexes after treatment, the levels of platelet aggregation rate (PAgT), fibrinogen (FIB), erythrocyte sedimentation rate (ESR), and whole blood viscosity (ηb) were lower in the experimental group than those in the control group ( P<0.05). In terms of the myocardial injury indexes after treatment, the levels of serum N-terminal pro-brain natriuretic peptide (NT-pro BNP) and cardiac troponin I (cTnI) were lower in the experimental group than those in the control group, while the levels of insulin-like growth factor 1 (IGF-1) and cardiotrophin 1 (CT-1) were higher in the experimental group than those in the control group ( P<0.05). In terms of the inflammatory indexes after treatment, the levels of interleukin-6 (IL-6), high-sensitive C-reactive protein (hs-CRP), and tumor necrosis factor-α (TNF-α) were lower in the experimental group than those in the control group ( P<0.05). The incidence of adverse reactions in the experimental group (9.80%) and that in the control group (7.84%) were comparable ( P>0.05). Conclusion: The use of dbcAMP-Ca in addition to metoprolol can effectively improve cardiac function, heart rate variability, and exercise tolerance, while inhibiting inflammatory response in elderly patients with heart failure combined with arrhythmia, with high medication safety. The combination medication shows better safety and therapeutic effects than those of metoprolol used alone.

Comparison of the efficacy, safety, and tolerability of the FDC of telmisartan + bisoprolol with telmisartan + metoprolol succinate ER combination therapy for stage 1 and stage 2 hypertension: A double-blind, multicentric, phase-III clinical study.

AIM: The present study compared the safety, efficacy, and tolerability of the new fixed-dose combination (FDC) of telmisartan 40 mg + bisoprolol 5 mg (TBP) tablets with the existing comparator FDC telmisartan 40 mg + metoprolol succinate ER 50 mg (TMS) tablets in patients with stage 1 and stage 2 hypertension. METHODOLOGY: The multicentric, double-blind, parallel-group, comparative, prospective, phase-III clinical study involved 264 subjects with stage 1 and stage 2 hypertension from 10 centres across India. The selected subjects were randomized into two groups: group A received the TMS and group B received the new FDC TBP. The primary endpoint was the mean change in seated systolic blood pressure (SeSBP) and seated diastolic blood pressure (SeDBP) from baseline to week 12 in both the control and study arms. The secondary endpoint was achieving the target of SeSBP <140 mmHg and SeDBP <90 mmHg from baseline to week 12 in both groups. Safety and tolerability parameters were evaluated in both groups based on adverse effects (AEs) reported by the patients and the physician. RESULTS: Both treatment groups exhibited a reduction in BP after 2 weeks of treatment, which was sustained until 12 weeks. The mean change in SeSBP and SeDBP at weeks 2, 6, and 12 compared to the previous visit showed statistical significance (p < 0.001) in all cases for both groups A and B. The mean changes in SeSBP and SeDBP from baseline to study end were numerically higher in group B than in group A. The mean difference in SeSBP from baseline to study end was significantly higher in group B compared to group A (p = 0.029). By week 12, 88.28 % and 89.84 % of subjects in group B achieved SeSBP <140 mmHg and SeDBP <90 mmHg respectively, while 86.71 % and 91.40 % of subjects in group A achieved the same targets. Reported AEs were mostly mild to moderate in both treatment groups, and no serious AEs or deaths were reported. Tolerability was rated as 'excellent' by 93.75 % of subjects in group B and 91.40 % of subjects in group A. CONCLUSION: Both the new FDC TBP and the existing comparator TMS combination therapy have comparable efficacy, tolerability, and safety for the management of stage 1 and stage 2 hypertension. TRIAL REGISTRY NAME: Clinical Trials Registry of India (CTRI) TRIAL REGISTRATION NO: CTRI/2021/11/037,926 PROTOCOL NO: MLBTL/05/2021 PROTOCOL URL: https://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=62069&EncHid=&userName=bisoprolol.

Development of a RP-HPLC method for simultaneous determination of atenolol, metoprolol tartrate and phenol red for in-situ rat intestinal perfusion studies.

Single-pass intestinal perfusion (SPIP) method is a widely used experimental model to determine the intestinal permeability of drugs. These studies are performed in the presence of a reference standard (metoprolol, MT) and a zero permeability marker (phenol red, PR). Therefore, it is important to develop a validated method for simultaneous determination of the investigated compound along with MT and PR. The aim of this study was to develop a reversed phase high-performance liquid chromatography (RP-HPLC) method with UV-detection for the simultaneous determination of atenolol (ATN), MT, and PR in the perfusion medium used in SPIP experiments. Separation of compounds were performed using an InertSustain C18 (250 × 4.6 mm, 5 µm) HPLC column at 35 °C. The mobile phase was a mixture of acetonitrile and phosphate buffer (pH 7.0, 12.5 mM) in gradient elution, and was delivered at a flow rate of 1 mL/min. The acetonitrile ratio of the mobile phase increased linearly from 10 to 35 % over 15 min. The injection volume was 20 µL, and ATN, MT and PR were detected at 224 nm. The retention times under optimum HPLC conditions were 5.028 min, 12.401 min, and 13.507 min for ATN, MT and PR, respectively. The developed RP-HPLC method was validated for selectivity, specificity, calibration curve and range, accuracy and precision, carry-over effect, stability, reinjection reproducibility, recovery and robustness. The method was linear for ATN (0.76-50 µg/mL), MT (1.14-50 µg/mL), and PR (0.47-20 µg/mL) with determination coefficients of 0.9999, 0.9994 and 0.9998, respectively. The results obtained for all validation parameters of the developed RP-HPLC method met the required limits of the ICH M10 Guideline.

Transformation of metoprolol in UV/PDS process: Role and mechanisms of degradation and polymerization.

Advanced oxidation processes for the treatment of organic pollutants in wastewater suffer from difficulties in mineralization, potential risks of dissolved residues, and high oxidant consumption. In this study, radical-initiated polymerization is dominated in an UV/peroxydisulfate (PDS) process to eliminate organic pollutant of pharmaceutical metoprolol (MTP). Compared with an ideal degradation-based UV/PDS process, the present process can save four fifths of PDS consumption at the same dissolved organic carbon removal of 47.3%. Simultaneously, organic carbon can be recovered from aqueous solution by separating solid polymers at a ratio of 50% of the initial chemical oxygen demand. The chemical structure of products was analyzed to infer the transformation pathways of MTP. Unlike previous studies on simple organic pollutants that the polymerization can occur independently, the polymerization of MTP is dependent on the partial degradation of MTP, and the main monomer in polymerization is a dominant degradation product (4-(2-methoxyethyl)-phenol, denoted as DP151). The separated solid polymers are formed by repeated oxidation and coupling of DP151 or its derivatives through a series of intermediate oligomers. This proof-of-concept study demonstrates the advantage of polymerization-dominated mechanism on dealing with large organic molecules with complex structures, as well as the potential of UV/PDS process for simultaneous organic pollution reduction and organic carbon recovery from aqueous solution.

Myosin inhibitor reverses hypertrophic cardiomyopathy in genotypically diverse pediatric iPSC-cardiomyocytes to mirror variant correction.

Pathogenic variants in MYH7 and MYBPC3 account for the majority of hypertrophic cardiomyopathy (HCM). Targeted drugs like myosin ATPase inhibitors have not been evaluated in children. We generate patient and variant-corrected iPSC-cardiomyocytes (CMs) from pediatric HCM patients harboring single variants in MYH7 (V606M; R453C), MYBPC3 (G148R) or digenic variants (MYBPC3 P955fs, TNNI3 A157V). We also generate CMs harboring MYBPC3 mono- and biallelic variants using CRISPR editing of a healthy control. Compared with isogenic and healthy controls, variant-positive CMs show sarcomere disorganization, higher contractility, calcium transients, and ATPase activity. However, only MYH7 and biallelic MYBPC3 variant-positive CMs show stronger myosin-actin binding. Targeted myosin ATPase inhibitors show complete rescue of the phenotype in variant-positive CMs and in cardiac Biowires to mirror isogenic controls. The response is superior to verapamil or metoprolol. Myosin inhibitors can be effective in genotypically diverse HCM highlighting the need for myosin inhibitor drug trials in pediatric HCM.

Comparison of the Effectiveness and Safety of Metoprolol and Diltiazem in Atrial Fibrillation With Rapid Ventricular Rate Patients: A Systematic Review and Meta-Analysis.

This study aims to assess the association between intravenous diltiazem and metoprolol in rate control for atrial fibrillation (AF) patients with rapid ventricular rate, focusing on rate control efficacy and hemodynamic adverse events. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, electronic searches were conducted in Embase, PubMed, and Cochrane Central Register of Controlled Trials (CENTRAL) until February 20, 2024. The primary outcome was achieving ventricular rate control < 110/min. Secondary outcomes included new hypotension (systolic blood pressure < 90 mm Hg) and bradycardia (heart rate < 60/min). Nineteen studies (three randomized controlled trials and 16 observational studies) were included in this meta-analysis. Pooled analysis showed intravenous metoprolol resulted in a 39% lower rate control attainment compared to diltiazem (OR: 0.61; 95% CI: 0.44 to 0.84; p = 0.002). There were no significant differences in bradycardia (OR: 0.51; 95% CI: 0.22 to 1.22; p = 0.13) or hypotension risk (OR: 1.08; 95% CI: 0.72 to 1.61; p = 0.72) between the two groups. Intravenous diltiazem demonstrated superior rate control efficacy compared to metoprolol in AF patients with rapid ventricular rate. However, no significant differences were observed in safety outcomes, namely, bradycardia and hypotension.

Napex acupoint thread-embedding combined with metoprolol tartrate tablet for prophylactic treatment of migraine without aura: a randomized controlled trial. / æž•é¡¹éƒ¨åŸ‹çº¿æ³•è”åˆé ’çŸ³é ¸ç¾Žæ‰˜æ´›å°”ç‰‡é¢„é˜²æ€§æ²»ç–—æ— å ˆå †åå¤´ç—›ï¼šéšæœºå¯¹ç §è¯•éªŒ.

OBJECTIVES: To observe the efficacy of napex acupoint thread-embedding combined with metoprolol tartrate tablet for prophylactic treatment of migraine without aura, and to compare its efficacy with simple napex acupoint thread-embedding and simple metoprolol tartrate tablet. METHODS: A total of 105 patients with migraine without aura were randomized into a combination group (35 cases, 5 cases dropped out), a thread-embedding group (35 cases, 4 cases dropped out) and a western medication group (35 cases, 2 cases dropped out). In the thread-embedding group, napex acupoint thread-embedding was applied at bilateral Fengchi (GB 20) and points of 1.5 cun nearby to the lower edge of spinous process of cervical 2. In the western medication group, metoprolol tartrate tablet was given orally, 12.5 mg a time, twice a day. In the combination group, napex acupoint thread-embedding combined with oral metoprolol tartrate tablet was delivered. The treatment of 8 weeks was required in the 3 groups. The days of headache attacks, frequency of headache attacks, headache severity (visual analogue scale [VAS] score) and the migraine specific quality of life questionnaire version 2.1 (MSQ) score were observed during baseline period (4 weeks before treatment to before treatment), observation period (1-4 weeks and 5-8 weeks in treatment) and follow-up period (1-4 weeks after treatment completion) respectively, the proportions of the days of headache attacks/frequency of headache attacks relieved by 50% were calculated, and the safety was evaluated in the 3 groups. RESULTS: During the observation period and the follow-up period, the days of headache attacks, frequency of headache attacks and headache VAS scores in the 3 groups were reduced compared with those of the baseline period (P<0.05). During the observation period and the follow-up period, the days of headache attacks and the frequency of headache attacks in the combination group were lower than those in the thread-embedding group and the western medication group (P<0.05); during the observation period (1-4 weeks in treatment), the headache VAS scores in the combination group and the thread-embedding group were lower than that in the western medication group (P<0.05); during the observation period (5-8 weeks in treatment) and the follow-up period, the headache VAS scores in the combination group were lower than those in the thread-embedding group and the western medication group (P<0.05). During the observation period and the follow-up period, the scores of role restriction, role prevention and emotion function of MSQ in the combination group were increased compared with those of the baseline period (P<0.05); during the observation period (5-8 weeks in treatment) and the follow-up period, the role prevention scores of MSQ in the thread-embedding group and the western medication group were increased compared with those of the baseline period (P<0.05); during the follow-up period, the emotion function scores of MSQ in the thread-embedding group and the western medication group were increased compared with those of the baseline period (P<0.05). During the observation period and the follow-up period, the scores of role restriction, role prevention and emotion function of MSQ in the combination group were higher than those in the thread-embedding group and the western medication group (P<0.05). There was no statistical difference in the proportions of the days of headache attacks/frequency of headache attacks relieved by 50% among the 3 groups (P>0.05), and there were no serious adverse reactions in the 3 groups. CONCLUSIONS: Napex acupoint thread-embedding combined with metoprolol tartrate tablet, simple napex acupoint thread-embedding and simple metoprolol tartrate tablet all can reduce the days of headache attacks and the frequency of headache attacks, relieve headache severity and improve the quality of life in patients with migraine without aura. Napex acupoint thread-embedding combined with metoprolol tartrate tablet has a better effect.

Age and mean platelet volume-based nomogram for predicting the therapeutic efficacy of metoprolol in Chinese pediatric patients with vasovagal syncope.

BACKGROUND: Vasovagal syncope (VVS) is the most common type of orthostatic intolerance in children. We investigated whether platelet-related factors related to treatment efficacy in children suffering from VVS treated with metoprolol. METHODS: Metoprolol-treated VVS patients were recruited. The median duration of therapy was three months. Patients were followed and divided into two groups, treament-effective group and treatment-ineffective group. Logistic and least absolute shrinkage selection operator regressions were used to examine treatment outcome variables. Receiver-operating characteristic (ROC) curves, precision-recall (PR) curves, calibration plots, and decision curve analyses were used to evaluate the nomogram model. RESULTS: Among the 72 patients who complete the follow-up, treatment-effective group and treatment-ineffective group included 42 (58.3%) and 30 (41.7%) cases, respectively. The patients in the treatment-effective group exhibited higher mean platelet volume (MPV) [(11.0 ± 1.0) fl vs. (9.8 ± 1.0) fl, P < 0.01] and platelet distribution width [12.7% (12.3%, 14.3%) vs. 11.3% (10.2%, 12.2%), P < 0.01] than those in the treatment-ineffective group. The sex ratio was significantly different (P = 0.046). A fit model comprising age [odds ratio (OR) = 0.766, 95% confidence interval (CI) = 0.594-0.987] and MPV (OR = 5.613, 95% CI = 2.297-13.711) might predict therapeutic efficacy. The area under the curve of the ROC and PR curves was computed to be 0.85 and 0.9, respectively. The P value of the Hosmer-Lemeshow test was 0.27. The decision curve analysis confirmed that managing children with VVS based on the predictive model led to a net advantage ranging from 0.01 to 0.58. The nomogram is convenient for clinical applications. CONCLUSION: A novel nomogram based on age and MPV can predict the therapeutic benefits of metoprolol in children with VVS.

[Deep eutectic solvents synergistic with carboxymethyl -ß-cyclodextrin on the improvement of chiral separation of metoprolol by capillary electrophoresis].

The physical and chemical properties of chiral drugs are very similar. However, their pharmacological and toxicological effects vary significantly. For example, one enantiomer may have favorable properties whereas the other may be ineffective or even have toxic side effects. Hence, exploring innovative strategies to improve enantiomeric resolution is of great importance. Metoprolol (MET) is a ß-receptor blocker used to treat hypertension, stable angina pectoris, and supraventricular tachyarrhythmia. Establishing chiral separation and analysis methods of MET enantiomers is important for enhancing the quality of chiral drugs. Capillary electrophoresis (CE) has the advantages of a small sample size, simple operation, high separation efficiency, and many alternative modes; therefore it is widely used in the field of chiral drug separation. The chiral selectors commonly used for CE-based chiral separation include cyclodextrin (CD) and its derivatives, polysaccharides, proteins, and macrocyclic antibiotics. CD is one of the most commonly used and effective chiral selectors for CE. The relatively hydrophobic structure inside the cavity and the relatively hydrophilic structure outside the cavity of CD enable it and chiral molecules to form inclusion compounds with different binding constants, thus achieving chiral separation. However, the use of CD alone as a chiral selector does not always yield satisfactory separation results. Hence, the addition of other additives, such as ionic liquids and deep eutectic solvents (DESs) to assist CD-based chiral separation systems has received extensive attention. Previous studies on the enantiomeric separation of MET by CE have focused on the addition of CD and its derivatives alone for separation. Few studies have been conducted on the synergistic addition of auxiliary additives to CD to improve the enantiomeric resolution of MET. In this study, three DESs, namely, choline chloride-D-glucose, choline chloride-D-fructose, and lactate-D-glucose, were used for the CE-based chiral separation of MET for the first time, and the synergistic effect of the DESs on the separation of MET enantiomers by CD-based capillary zone electrophoresis was speculated. For this purpose, an uncoated fused silica capillary with inner diameter of 50 µm, total length of 50 cm and effective length of 41.5 cm was used as the separation column. First, the effects of CD type, CD concentration, buffer pH, and buffer concentration on MET separation were investigated, and the optimal conditions (15 mmol/L carboxymethyl-ß-cyclodextrin (CM-ß-CD), pH=3.0, and 40 mmol/L phosphate buffer) were obtained. Other CE conditions were as follows: UV detection at 230 nm, applied voltage of 25 kV. All operations were carried out at 20 ℃. Next, three types of DESs were prepared as auxiliary additives via a mixed-heating method. The DESs were mixed in a 50 mL round-bottomed flask at a certain molar ratio and then heated in a water bath at 80 ℃ for 3 h until a clear and transparent liquid was obtained. The effects of different DESs and their mass fraction on chiral separation were subsequently studied. The optimal choline chloride-D-fructose mass fraction was ultimately determined to be 1.5%. The resolution of MET increased from 1.30 without DES to 2.61 with 1.5% choline chloride-D-fructose, thereby achieving baseline separation. Finally, the separation effect and mechanism were speculated. The MET chiral separation method established in this study is of great significance for improving the quality of chiral compounds and ensuring the safety and effectiveness of clinical drugs. Furthermore, it may be useful in the research and development of CE-based chiral separation techniques using CD derivatives with DESs.

Development of a hollow fiber-liquid phase microextraction method using tissue culture oil for the extraction of free metoprolol from plasma samples.

In this research, a method known as a hollow fiber-liquid-phase microextraction was employed to extract and concentrate free metoprolol from plasma samples. The extracted analyte was subsequently determined using high-performance liquid chromatography coupled with a diode-array detector. Several parameters, including hollow fiber length, sonication time, extraction temperature, and salt addition, were investigated and optimized to enhance extraction efficiency. After extracting the analyte under optimum conditions from plasma samples, the enrichment factor and extraction recovery were 50 and 86 %, respectively. Moreover, the method exhibited detection and quantification limits of 0.41 and 1.30 ng mL-1, respectively. The analysis of real samples demonstrated satisfactory relative recoveries in the range of 91-99 %.

Comparing the effects of various ß-blockers on cardiovascular mortality in breast cancer patients.

BACKGROUND: Cardiovascular (CV) disease is a leading cause of death in breast cancer (BC) patients due to the increased age and treatments. While individual ß-blockers have been investigated to manage CV complications, various ß-blockers have not been compared for their effects on CV death in this population. We aimed to compare CV mortality in older BC patients taking one of the commonly used ß-blockers. METHODS: This retrospective cohort study was conducted using the Surveillance, Epidemiology and End Results (SEER) - Medicare data (2010-2015). Patients of age 66 years or older at BC diagnosis receiving metoprolol, atenolol, or carvedilol monotherapy were included. The competing risk regression model was used to determine the risk of CV mortality in the three ß-blocker groups. The multivariable model was adjusted for demographic and clinical covariates. The adjusted hazard ratio (HR) and 95% confidence intervals (CI) were reported for the risk of CV mortality. RESULTS: The study cohort included 6,540 patients of which 55% were metoprolol users, 30% were atenolol users, and 15% were carvedilol users. Metoprolol was associated with a 37% reduced risk of CV mortality (P = 0.03) compared to carvedilol after adjusting for the covariates (HR = 0.63; 95% CI 0.41-0.96). No significant difference in the risk of CV mortality between atenolol and carvedilol users was observed (HR = 0.74; 95% CI 0.44-1.22). CONCLUSIONS: Our findings suggest that metoprolol is associated with a reduced risk of CV mortality in BC patients. Future studies are needed to confirm these findings and understand the mechanism of action.

Design of Experimental Approach for Development of Rapid High Performance Liquid Chromatographic Process for Simultaneous Estimation of Metoprolol, Telmisartan, and Amlodipine from Formulation: Greenness and Whiteness Evaluation.

The design of an experimental approach, the Box-Behnken design, was implemented to optimize the chromatographic condition to develop a rapid HPLC procedure for quantification of a ternary mixture of metoprolol (MET), telmisartan (TEL), and amlodipine (AML) from the formulation. The perturbation plots, contour, and 3D response surface pictures were developed to study the impact of each variable on the analytes' retention time and the probable interaction between the parameters with fewer chromatographic runs. The optimized HPLC method separated the three analytes within 5 min with excellent selectivity and peak shape on a Zorbax C18 HPLC column using acetonitrile and phosphate buffer (20 mM, pH 5.8) with isocratic elution at a 1.1 mL/min flowrate. A wavelength 230 nm was utilized to monitor the elute. The validation of proposed method demonstrated a wide linearity range of 10-200 µg/mL for MET and TEL and 5-50 µg/mL for AML along with an excellent correlation coefficient. The correctness of the HPLC approach was further confirmed by excellent recovery of the added amount of analytes utilizing the standard addition technique. The recommended HPLC approach was employed safely for quality assurance of the formulation, because the evaluation of the method's greenness and whiteness confirmed the environmentally friendly nature of the approach.

Beta-blocker therapy in heart failure with preserved ejection fraction (B-HFpEF): A systematic review and meta-analysis.

INTRODUCTION: While beta-blockers are considered the cornerstone of treatment for heart failure with reduced ejection fraction, the same may not apply to patients with heart failure with preserved ejection fraction (HFpEF). To date, the benefit of beta-blockers remains uncertain, and there is no current consensus on their effectiveness. This study sought to evaluate the efficacy of beta-blockers on mortality and rehospitalization among patients with HFpEF. METHODS: A systematic review and meta-analysis of randomized or observational cohort studies examined the efficacy of beta-blocker therapy in comparison with placebo, control, or standard medical care in patients with HFpEF, defined as left ventricular ejection fraction ≥50 %. The main endpoints were mortality (i.e., all-cause and cardiovascular), rehospitalization (i.e., all-cause and for heart failure) and a composite of the two. RESULTS: Out of the 13,189 records initially identified, 16 full-text records met the inclusion criteria and were analyzed recruiting a total of 27,188 patients. The mean age range was 62-84 years old, predominantly female, with HFpEF in which 63.4 % of patients received a beta-blocker and 36.6 % did not. The pooled analysis of included cohort studies, of variable follow-up durations, showed a significant reduction in all-cause mortality by 19 % (odds ratio (OR) 0.81; 95 % confidence interval (CI): 0.65-0.99, p = 0.044) whereas rehospitalization for heart failure (OR 1.13; 95 % CI: 0.91-1.41, p = 0.27) or its composite with all-cause mortality (OR 1.01; 95 % CI: 0.78-1.32, p = 0.92) were similar between the beta-blocker and control groups. CONCLUSION: This meta-analysis showed that beta-blocker therapy has the potential to reduce all-cause mortality in patients with HFpEF based on observational studies. Nevertheless, it did not affect rehospitalization for heart failure or its composite with all-cause mortality. Large scale randomized trials are needed to clarify this uncertainty.

Silicon-Based Piezo Micropumps Enable Fully Flexible Drug Delivery Patterns.

Drug release plays a crucial role in drug delivery. While current formulation approaches are capable of coarse-tuning the release profile, their precision and reproducibility are limited by the physicochemical properties of the excipients and active pharmaceutical ingredient (API). Innovative and advanced approaches are urgently needed, especially for site-specific targeting of drugs and to address their pharmacological requirements for optimal therapy. The 5 × 5 × 0.6 mm3 piezoelectric micropump developed by Fraunhofer EMFT was designed to enable precise drug delivery in a low volume format. In this study, we investigated the ability of the micropump to deliver solutions of highly soluble APIs using a wide range of customized pump profiles. Additionally, we examined the ability of the micropump to deliver suspensions containing various defined particle sizes. While results for suspensions indicate that pumping performance is highly dependent on the size and concentration of the suspended particles, results with API solutions demonstrate high precision and reproducibility of release, coupled with maximum flexibility in the release profile of the API. The piezoelectric micropump thus lays the cornerstone in the development of a wide range of innovative drug delivery profiles, enabling customized release profiles to be programmed and thus paving the way to fully personalized medicine.

Evaluation of in vitro dissolution profiles of modified-release metoprolol succinate tablets crushed using mortar and pestle technique.

PURPOSE: Clinical practice guidelines advise against crushing modified-release dosage forms. Metoprolol succinate modified-release (MS-MR) tablets are commonly crushed in clinical practice to facilitate administration to patients with swallowing difficulties or using feeding tubes. To date, the effect of this practice remains unexplored. The in vitro effects of crushing commercially available MS-MR tablets were explored using a holistic approach. METHODS: Dissolution profiles of crushed versus whole MS-MR tablets were compared. Tablets were crushed to powder state using pragmatic method mimicking hospital practices. For standardization purposes, the same operator, duration (60 seconds), hand, and mortar-pestle apparatus were used. Dissolution studies were conducted per U.S. Pharmacopeia at pH 1.2, pH 4.5, and pH 6.8 with USP apparatus 2 (paddle) at rotation speed of 50 rpm at 37±0.5 °C in 500 mL dissolution media. Samples were withdrawn at predetermined time points. Percent drug dissolved was measured by validated UV-vis Spectrophotometry. Comprehensive analysis of the dissolution data was conducted using model-independent, model-dependent, and ANOVA-based approaches (SPSS v.23 at α=0.05). Similarity (f2) and difference (f1) factors were calculated to compare the dissolution profiles between crushed (CT) and whole tablets (WT). Goodness of fit (GOF) analysis examined the compliance between in vitro dissolution behaviors and several drug release models. Model selection was based on GOF plots, Akaike criteria and adjusted coefficient of determination (R2adj). Imaging and particle size distribution analysis were conducted to examine associated surface and morphologic changes. RESULTS: The dissolution profiles were not similar at pH 4.5 (f2=45.43, f1=18.97) and pH 6.8 (f2=31.47, f1=32.94). CT best fitted with Higuchi (pH 1.2: R2adj=0.9990), Weibull (pH 4.5: R2adj=0.9884), and Korsmeyer-Peppas (pH 6.8: R2adj=0.9719). Contrastingly, WT best fitted with Hopfenberg (pH 1.2: R2adj=0.9986), logistic (pH 4.5: R2adj=0.9839) and first-order (pH 6.8: R2adj=0.9979) models. A significant difference in the dissolution profiles was found between CT and WT using multivariate analysis of variance per time points and between the tablet forms (p=0.004). This was confirmed by unparalleled dissolution profiles. Crushing resulted in variations in particle size and surface morphological changes to the micropellets. CONCLUSION: Crushing practices change the dissolution profile of MS-MR tablets by deforming the surface morphology of embedded micropellets. Amounts of drug dissolved between CT and WT were not the same at the compared time points across gastrointestinal pH ranges. This suggests potential clinical impact on plasma-concentration profiles of critically ill patients using feeding tube.

Mechanism-Based Inactivation of CYP2D6 by Phellopterin and Related Drug-Drug Interaction with Metoprolol.

Phellopterin (PLP) is a linear furanocoumarin widely found in citrus fruits and herbal medicines. The study aims to comprehensively investigate the mechanism of inhibition of CYP2D6 enzyme activity by PLP and its alteration of metoprolol pharmacokinetics. PLP was found to irreversibly inhibit CYP2D6 in time-, concentration-, and nicotinamide adenine dinucleotide phosphate-dependent manners. Coincubation with quinidine, which is a competitive inhibitor of CYP2D6, attenuated this time-dependent inhibition. Glutathione (GSH) and catalase/superoxide dismutase failed to reverse the PLP-induced CYP2D6 inactivation. GSH trapping experiments provided strong evidence that PLP metabolic activation produces epoxide or γ-ketoaldehyde intermediates. In addition, pretreatment with PLP resulted in significant increases in Cmax and area under curve of plasma metoprolol in rats.