Beta-blockers or Placebo for Primary Prophylaxis (BOPPP) of oesophageal varices: study protocol for a randomised controlled trial.

BACKGROUND: Liver disease is within the top five causes of premature death in adults. Deaths caused by complications of cirrhosis continue to rise, whilst deaths related to other non-liver disease areas are declining. Portal hypertension is the primary sequelae of cirrhosis and is associated with the development of variceal haemorrhage, ascites, hepatic encephalopathy and infection, collectively termed hepatic decompensation, which leads to hospitalisation and mortality. It remains uncertain whether administering a non-selective beta-blocker (NSBB), specifically carvedilol, at an earlier stage, i.e. when oesophageal varices are small, can prevent VH and reduce all-cause decompensation (ACD). METHODS/DESIGN: The BOPPP trial is a pragmatic, multicentre, placebo-controlled, triple-blinded, randomised controlled trial (RCT) in England, Scotland, Wales and Northern Ireland. Patients aged 18 years or older with cirrhosis and small oesophageal varices that have never bled will be recruited, subject to exclusion criteria. The trial aims to enrol 740 patients across 55 hospitals in the UK. Patients are allocated randomly on a 1:1 ratio to receive either carvedilol 6.25 mg (a NSBB) or a matched placebo, once or twice daily, for 36 months, to attain adequate power to determine the effectiveness of carvedilol in preventing or reducing ACD. The primary outcome is the time to first decompensating event. It is a composite primary outcome made up of variceal haemorrhage (VH, new or worsening ascites, new or worsening hepatic encephalopathy (HE), spontaneous bacterial peritonitis (SBP), hepatorenal syndrome, an increase in Child-Pugh grade by 1 grade or MELD score by 5 points, and liver-related mortality. Secondary outcomes include progression to medium or large oesophageal varices, development of gastric, duodenal, or ectopic varices, participant quality of life, healthcare costs and transplant-free survival. DISCUSSION: The BOPPP trial aims to investigate the clinical and cost-effectiveness of carvedilol in patients with cirrhosis and small oesophageal varices to determine whether this non-selective beta-blocker can prevent or reduce hepatic decompensation. There is clinical equipoise on whether intervening in cirrhosis, at an earlier stage of portal hypertension, with NSBB therapy is beneficial. Should the trial yield a positive result, we anticipate that the administration and use of carvedilol will become widespread with pathways developed to standardise the administration of the medication in primary care. ETHICS AND DISSEMINATION: The trial has been approved by the National Health Service (NHS) Research Ethics Committee (REC) (reference number: 19/YH/0015). The results of the trial will be submitted for publication in a peer-reviewed scientific journal. Participants will be informed of the results via the BOPPP website ( www.boppp-trial.org ) and partners in the British Liver Trust (BLT) organisation. TRIAL REGISTRATION: EUDRACT reference number: 2018-002509-78. ISRCTN reference number: ISRCTN10324656. Registered on April 24 2019.

Beta-Blockers after Myocardial Infarction and Preserved Ejection Fraction.

BACKGROUND: Most trials that have shown a benefit of beta-blocker treatment after myocardial infarction included patients with large myocardial infarctions and were conducted in an era before modern biomarker-based diagnosis of myocardial infarction and treatment with percutaneous coronary intervention, antithrombotic agents, high-intensity statins, and renin-angiotensin-aldosterone system antagonists. METHODS: In a parallel-group, open-label trial performed at 45 centers in Sweden, Estonia, and New Zealand, we randomly assigned patients with an acute myocardial infarction who had undergone coronary angiography and had a left ventricular ejection fraction of at least 50% to receive either long-term treatment with a beta-blocker (metoprolol or bisoprolol) or no beta-blocker treatment. The primary end point was a composite of death from any cause or new myocardial infarction. RESULTS: From September 2017 through May 2023, a total of 5020 patients were enrolled (95.4% of whom were from Sweden). The median follow-up was 3.5 years (interquartile range, 2.2 to 4.7). A primary end-point event occurred in 199 of 2508 patients (7.9%) in the beta-blocker group and in 208 of 2512 patients (8.3%) in the no-beta-blocker group (hazard ratio, 0.96; 95% confidence interval, 0.79 to 1.16; P = 0.64). Beta-blocker treatment did not appear to lead to a lower cumulative incidence of the secondary end points (death from any cause, 3.9% in the beta-blocker group and 4.1% in the no-beta-blocker group; death from cardiovascular causes, 1.5% and 1.3%, respectively; myocardial infarction, 4.5% and 4.7%; hospitalization for atrial fibrillation, 1.1% and 1.4%; and hospitalization for heart failure, 0.8% and 0.9%). With regard to safety end points, hospitalization for bradycardia, second- or third-degree atrioventricular block, hypotension, syncope, or implantation of a pacemaker occurred in 3.4% of the patients in the beta-blocker group and in 3.2% of those in the no-beta-blocker group; hospitalization for asthma or chronic obstructive pulmonary disease in 0.6% and 0.6%, respectively; and hospitalization for stroke in 1.4% and 1.8%. CONCLUSIONS: Among patients with acute myocardial infarction who underwent early coronary angiography and had a preserved left ventricular ejection fraction (≥50%), long-term beta-blocker treatment did not lead to a lower risk of the composite primary end point of death from any cause or new myocardial infarction than no beta-blocker use. (Funded by the Swedish Research Council and others; REDUCE-AMI ClinicalTrials.gov number, NCT03278509.).

The clinical value of ß-blockers in patients with stable angina.

Stable angina, one manifestation of chronic coronary syndrome (CCS), is characterised by intermittent episodes of insufficient blood supply to the myocardium, provoking symptoms of myocardial ischaemia, particularly chest pain. These attacks usually occur during exercise or stress. Anti-ischaemic drugs are the mainstay of pharmacologic management of CCS with symptoms of angina. ß-blockers reduce heart rate and myocardial contractility, thus reducing myocardial oxygen consumption. These drugs have been shown to ameliorate the frequency of anginal attacks and to improve exercise capacity in these patients. Current management guidelines include ß-blockers as a first-line management option for most patients with CCS and symptoms of myocardial ischaemia, alongside dihydropyridine calcium channel blockers (CCB). The presence of comorbid angina and heart failure is a strong indication for starting with a ß-blocker. ß-blockers are also useful in the management of angina symptoms accompanied by a high heart rate, hypertension (with or without a renin-angiotensin-aldosterone-system [RAS] blocker or CCB), or microvascular angina (with a RAS blocker and a statin). A ß-blocker is not suitable for a patient with low heart rate (<50 bpm), although use of a ß-blocker may be supported by a pacemaker if the ß-blocker is strongly indicated) and should be used at a low dose only in patients with low blood pressure.

ß-blockers are not all the same: pharmacologic similarities and differences, potential combinations and clinical implications.

ß-blockers are a heterogeneous class, with individual agents distinguished by selectivity for ß1- vs. ß2- and α-adrenoceptors, presence or absence of partial agonist activity at one of more ß-receptor subtype, presence or absence of additional vasodilatory properties, and lipophilicity, which determines the ease of entry the drug into the central nervous system. Cardioselectivity (ß1-adrenoceptor selectivity) helps to reduce the potential for adverse effects mediated by blockade of ß2-adrenoceptors outside the myocardium, such as cold extremities, erectile dysfunction, or exacerbation of asthma or chronic obstructive pulmonary disease. According to recently updated guidelines from the European Society of Hypertension, ß-blockers are included within the five major drug classes recommended as the basis of antihypertensive treatment strategies. Adding a ß-blocker to another agent with a complementary mechanism may provide a rational antihypertensive combination that minimizes the adverse impact of induced sympathetic overactivity for optimal blood pressure-lowering efficacy and clinical outcomes benefit.

The current position of ß-blockers in hypertension: guidelines and clinical practice.

The benefits of improved clinical outcomes through blood pressure (BP) reduction have been proven in multiple clinical trials and meta-analyses. The new (2023) guideline from the European Society of Hypertension (ESH) includes ß-blockers within five main classes of antihypertensive agents suitable for initiation of antihypertensive pharmacotherapy and for combination with other antihypertensive agents. This is in contrast to the 2018 edition of ESH guidelines that recommended ß-blockers for use primarily in patients with compelling indications such as cardiovascular comorbidities, e.g. coronary heart disease, heart failure. This change was based on the fact that the magnitude of BP reduction is the most important factor for adverse cardiovascular outcomes, over and above the precise manner in which reduced BP is achieved. The ESH guideline also supports the use of ß-blockers for patients with resting heart rate (>80 bpm); high resting heart rate is a sign of sympathetic overactivity, an important driver of adverse cardiac remodelling in the setting of hypertension and heart failure. Hypertension management guidelines support for the use of combination therapies for almost all patients with hypertension, ideally within a single-pill combination to optimise adherence to therapy. Where a ß-blocker is prescribed, the inclusion of a dihydropyridine calcium channel blocker within a combination regimen is rational. These agents together reduce both peripheral and central BP, which epidemiological studies have shown is important for reducing the burden of premature morbidity and mortality associated with uncontrolled hypertension, especially strokes.

Safety and tolerability of ß-blockers: importance of cardioselectivity.

Cardioselective ß-blockade is generally well tolerated in practice and contraindications to this therapy are uncommon. ß-blockers are a diverse therapeutic class, and their individual tolerability profiles are influenced strongly by their pharmacodynamic effects across different adrenergic receptors. Bisoprolol, probably the ß-blocker with the highest selectivity for blockade of ß1- vs. ß2-adrenoceptors, does not block ß2-adrenoceptors to an appreciable extent at doses in therapeutic use. Side-effects often attributed to ß-blockers, such as erectile dysfunction and adverse metabolic effects are uncommon with bisoprolol and other ß-blockers used at doses which only block ß1-adrenoceptors. Cautious use of a cardioselective ß-blocker is not contraindicated in people with chronic obstructive pulmonary disease or asthma and the outcomes benefits of ß-blockers in patients with coronary heart disease or heart failure are also apparent in patients with concurrent COPD. Starting with a low dose and titrating upwards carefully is important for optimising the tolerability of a ß-blocker. Most people with hypertension will receive combination antihypertensive therapy in practice, and the low-dose combination therapy approach provides a useful strategy for optimising the efficacy and tolerability of a regimen that includes a ß-blocker, compared with up-titrating an existing monotherapy.

Heart failure management with ß-blockers: can we do better?

Heart failure (HF) is associated with disabling symptoms, poor quality of life, and a poor prognosis with substantial excess mortality in the years following diagnosis. Overactivation of the sympathetic nervous system is a key feature of the pathophysiology of HF and is an important driver of the process of adverse remodelling of the left ventricular wall that contributes to cardiac failure. Drugs which suppress the activity of the renin-angiotensin-aldosterone system, including ß-blockers, are foundation therapies for the management of heart failure with reduced ejection fraction (HFrEF) and despite a lack of specific outcomes trials, are also widely used by cardiologist in patients with HF with preserved ejection fraction (HFpEF). Today, expert opinion has moved away from recommending that treatment for HF should be guided solely by the LVEF and interventions should rather address signs and symptoms of HF (e.g. oedema and tachycardia), the severity of HF, and concomitant conditions. ß-blockers improve HF symptoms and functional status in HF and these agents have demonstrated improved survival, as well as a reduced risk of other important clinical outcomes such as hospitalisation for heart failure, in randomised, placebo-controlled outcomes trials. In HFpEF, ß-blockers are anti-ischemic and lower blood pressure and heart rate. Moreover, ß-blockers also reduce mortality in the setting of HF occurring alongside common comorbid conditions, such as diabetes, CKD (of any severity), and COPD. Higher doses of ß-blockers are associated with better clinical outcomes in populations with HF, so that ensuring adequate titration of therapy to their maximal (or maximally tolerated) doses is important for ensuring optimal outcomes for people with HF. In principle, a patient with HF could have combined treatment with a ß-blocker, renin-angiotensin-aldosterone system inhibitor/neprilysin inhibitor, mineralocorticoid receptor antagonist, and a SGLT2 inhibitor, according to tolerability.

Initiation and continuation of pharmacological therapies in patients hospitalized for heart failure in Japan.

Currently, the utilization patterns of medications for heart failure (HF) after worsening HF events remain unelucidated in Japan. Here, we conducted a retrospective cohort study evaluating the changes in HF drug utilization patterns in 6 months before and after hospitalizations for HF. The adherence to newly initiated HF medications was evaluated based on the proportion of days covered (PDC) and persistence as continuous treatment episodes among new users. The study included 9091 patients hospitalized for HF between January 2016 and September 2019, including 2735 (30.1%) patients who were newly prescribed at least one HF medication after hospitalization. Despite increases in the use of foundational HF therapy (beta-blockers, angiotensin-converting-enzyme inhibitors/angiotensin receptor blockers, or mineralocorticoid receptor antagonists), 35.6% and 7.6% of patients were treated with the HF foundational monotherapy or diuretics alone after hospitalization, respectively. The mean PDC of newly initiated HF medications ranged from 0.57 for thiazide diuretics to 0.77 for sodium-glucose cotransporter-2 inhibitors. Continuous use of HF medications during the first year after initiation was observed in 30-60% of patients. The mean PDC and one-year continuous HF medication use were consistently lower in patients aged ≥ 75 years and in patients with a history of HF hospitalization for all HF medication classes except for tolvaptan and digoxin. Despite the guideline recommendations of HF pharmacotherapy, both treatment and adherence were suboptimal after HF hospitalization, especially in vulnerable populations such as older patients and those with prior HF hospitalizations.

Study on genotype and phenotype of novel CYP2D6 variants using pharmacokinetic and pharmacodynamic models with metoprolol as a substrate drug.

To investigate the pharmacokinetic and pharmacodynamic profiles of volunteers carrying CYP2D6 genotypes with unknow metabolic phenotypes, a total of 22 volunteers were recruited based on the sequencing results. Peripheral blood and urine samples were collected at specific time points after oral administration of metoprolol. A validated high-performance liquid chromatography (HPLC) method was used to determine the concentrations of metoprolol and α-hydroxymetoprolol. Blood pressure and electrocardiogram were also monitored. The results showed that the main pharmacokinetic parameters of metoprolol in CYP2D6*1/*34 carriers are similar to those in CYP2D6*1/*1 carriers. However, in individuals carrying the CYP2D6*10/*87, CYP2D6*10/*95, and CYP2D6*97/*97 genotypes, the area under the curve (AUC) and half-life (t1/2) of metoprolol increased by 2-3 times compared to wild type. The urinary metabolic ratio of metoprolol in these genotypes is consistent with the trends observed in plasma samples. Therefore, CYP2D6*1/*34 can be considered as normal metabolizers, while CYP2D6*10/*87, CYP2D6*10/*95, and CYP2D6*97/*97 are intermediate metabolizers. Although the blood concentration of metoprolol has been found to correlate with CYP2D6 genotype, its blood pressure-lowering effect reaches maximum effectiveness at a reduction of 25 mmHg. Furthermore, P-Q interval prolongation and heart rate reduction are not positively correlated with metoprolol blood exposure. Based on the pharmacokinetic-pharmacodynamic model, this study clarified the properties of metoprolol in subjects with novel CYP2D6 genotypes and provided important fundamental data for the translational medicine of this substrate drug.

Enteropathy and intestinal malabsorption in patients treated with antihypertensive drugs. A retrospective cohort study.

OBJECTIVES: To investigate differences in the incidence of enteropathy or intestinal malabsorption in patients taking angiotensin II receptor blockers (ARBs), angiotensin-converting enzyme inhibitor (ACEI), calcium channel blocker (CCB), and beta blockers (BBs) at a single center in Korea. METHODS: In this retrospective study, we utilized data from the Yangsan electronic medical records to identify 129,169 patients. These individuals were prescribed olmesartan, other ARBs, ACEI, CCB, and BBs between November 2008 and February 2021. RESULTS: Of the 44,775 patients, 51 (0.11%) were observed to have enteropathy or intestinal malabsorption. Compared with the ACEI group, the adjusted odds ratios (ORs) for enteropathy and intestinal malabsorption were OR=1.313 (95% confidence interval [CI]: [0.188-6.798], p=0.893) for olmesartan, OR=0.915 (95% CI: [0.525-1.595], p=0.754) for the other ARBs, OR=0.928 (95% CI: [0.200-4.307]; p=0.924) for the CCB, and OR=0.663 (95% CI: [0.151-2.906]; p=0.586) for the BBs group. These findings were adjusted for factors such as age, gender, duration of antihypertensive medication, and comorbidities. CONCLUSION: In a retrospective cohort study of patients on antihypertensive medications, no significant difference was found in the incidence of enteropathy or intestinal malabsorption when ACEI was compared to olmesartan, other ARBs, CCB, and BBs.

Probable interacción farmacológica entre sulfonilurea y betabloqueante en paciente con DM-II. Un reporte de caso / Probable pharmacological interaction between sulfonylurea and beta blocker in patients with DM-II. A case report

El estudio presenta el caso de una mujer de 47 años con diabetes tipo 2 (DM-II), hipertensión y anemia, tratada con metformina, glibenclamida, metoprolol y hierro/ácido fólico. Se identificó una interacción farmacológica entre glibenclamida y metoprolol, causando síntomas de hipoglucemia por la tarde. La evaluación mediante la Escala de Probabilidad de Interacciones Farmacológicas (EPIF) de Horn sugirió una interacción probable. El análisis farmacocinético reveló que el tiempo en el cual se alcanzan las concentraciones máximas de ambos fármacos coincidía con el inicio de los síntomas. Se implementó un nuevo horario de medicación que resolvió los síntomas. La interacción farmacológica se atribuyó al bloqueo de los efectos adrenérgicos por el metoprolol, comprometiendo la capacidad de contrarrestar la acción de la insulina liberada por la glibenclamida. Se resalta la importancia de la vigilancia, la toma de decisiones informadas y la implementación de estrategias preventivas para garantizar la seguridad y eficacia del tratamiento farmacológico en pacientes con condiciones clínicas específicas, como la DM-II y enfermedades cardiovasculares concomitantes.(AU)

The influence of carvedilol posology timing on clinically significant portal hypertension: insights from elastography measurements.

BACKGROUND AND AIMS: Carvedilol has emerged as the preferred ß-blocker for treating portal hypertension. However, there is still a debate in dosing regimen, with a potential lower bioavailability in once-daily regimens. The aim of this study is to assess the acute effects of carvedilol posology in patients with clinically significant portal hypertension (CSPH), as a surrogate marker of bioavailability. METHODS: In this experimental study, 34 patients with CSPH receiving carvedilol twice daily were asked to suppress the night dose of carvedilol, creating a standardized 24-hour dose interval. Spleen stiffness measurement (SSM) and liver stiffness measurement (LSM) by transient elastography (TE) were performed, with the exact interval between the last carvedilol administration and TE measurements consistently maintained at 24 hours and compared with values prior and under treatment. RESULTS: Thirty-four patients were included, predominantly male (82.9%). SSM after suspending carvedilol for 24 hours [mean, 73.9kPa (SD, 17.0)] was significantly higher ( P < 0.001) than under treatment [mean, 56.3kPa (SD, 13.2)] and was not significantly different ( P = 0.908) from SSM prior to introduction of carvedilol [mean, 74.5kPa (SD, 12.4)]. Differences were also found in stratified analysis for carvedilol dosage, D'Amico classification stages, MELDNa scores, MELD3.0 scores, Child-Pugh class A and CSPH due to alcoholic cirrhosis. LSM after suspension was not significantly different from both under treatment and prior to treatment. CONCLUSION: The differences in SSM after skipping one dose of carvedilol show both the importance of strict adherence to the prescribed dosing regimen to achieve the expected therapeutic benefits and the impact of twice daily prescription in bioavailability throughout the day.

Pediatric Beta Blocker Therapy: A Comprehensive Review of Development and Genetic Variation to Guide Precision-Based Therapy in Children, Adolescents, and Young Adults.

Beta adrenergic receptor antagonists, known as beta blockers, are one of the most prescribed medications in both pediatric and adult cardiology. Unfortunately, most of these agents utilized in the pediatric clinical setting are prescribed off-label. Despite regulatory efforts aimed at increasing pediatric drug labeling, a majority of pediatric cardiovascular drug agents continue to lack pediatric-specific data to inform precision dosing for children, adolescents, and young adults. Adding to this complexity is the contribution of development (ontogeny) and genetic variation towards the variability in drug disposition and response. In the absence of current prospective trials, the purpose of this comprehensive review is to illustrate the current knowledge gaps regarding the key drivers of variability in beta blocker drug disposition and response and the opportunities for investigations that will lead to changes in pediatric drug labeling.

Optimal Medical Therapy for Stable Ischemic Heart Disease: Focus on Anti-anginal Therapy.

Chronic coronary disease (CCD) is a major cause of morbidity and mortality worldwide. The most common symptom of CCD is exertional angina pectoris, a discomfort in the chest that commonly occurs during activities of daily life. Patients are dismayed by recurring episodes of angina and seek medical help in preventing or minimizing episodes. Angina occurs when the coronary arteries are unable to supply sufficient blood flow to the cardiac muscle to meet the metabolic needs of the left ventricular myocardium. While lifestyle changes and aggressive risk factor modification play a critical role in the management of CCD, management of angina usually requires pharmacologic therapy. Medications such as beta-blockers, calcium channel blockers, nitrates, ranolazine, and others ultimately work to improve the mismatch between myocardial blood flow and metabolic demand. This manuscript briefly describes the pathophysiologic basis for symptoms of angina, and how currently available anti-anginal therapies contribute to preventing or minimize the occurrence of angina.

Risk of Death and Cardiovascular Events in Asian Patients With Atrial Fibrillation and Chronic Obstructive Pulmonary Disease: A Report From the Prospective APHRS Registry.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is associated with an increased risk of adverse events in patients with atrial fibrillation (AF); however, few data are available on this topic in Asian populations. METHODS AND RESULTS: Prospective observational study conducted on patients with AF enrolled in the Asia-Pacific Heart Rhythm Society (APHRS) AF Registry. The diagnosis of COPD was based on data reported in the case report form by the investigators. Cox-regression models were used to assess the 1-year risk of a primary composite outcome of all-cause death, thromboembolic events, acute coronary syndrome, and heart failure. Analysis on single outcomes and cardiovascular death was also performed. Interaction analysis was used to assess the risk of composite outcome and all-cause death in different subgroups. The study included 4094 patients with AF (mean±SD age 68.5±12 years, 34.6% female), of whom 112 (2.7%) had COPD. Patients with COPD showed a higher incidence of the primary composite outcome (25.1% versus 6.3%, P<0.001), all-cause death (14.9% versus 2.6%, P<0.001), cardiovascular death (2.0% versus 0.6%, P<0.001), and heart failure (8.3% versus 6.0%, P<0.001). On multiple Cox-regression analysis, COPD was associated with a higher risk of the primary composite outcome (hazard ratio [HR], 3.17 [95% CI, 2.05-4.90]), all-cause death (HR, 3.59 [95% CI, 2.04-6.30]), and heart failure (HR, 3.32 [95% CI, 1.56-7.03]); no statistically significant differences were found for other outcomes. The association between COPD and mortality was significantly modified by the use of beta blockers (Pint=0.018). CONCLUSIONS: In Asian patients with AF, COPD is associated with worse prognosis. In patients with AF and COPD, the use of beta blockers was associated with a lower mortality. REGISTRATION INFORMATION: clinicaltrials.gov Identifier: NCT04807049.

Propranolol monotherapy in angiosarcoma - A window-of-opportunity study (PropAngio).

BACKGROUND: Angiosarcoma is a rare and aggressive cancer of the endothelial cells. Propranolol, a non-selective ß-blocker, was able to initiate apoptosis in angiosarcoma cell lines and its anti-tumor activity has been described in several case reports. The aim of this trial was to prospectively evaluate the anti-tumor activity of propranolol monotherapy in patients with angiosarcoma before proceeding to standard of care treatment. METHODS: Propranolol was dosed 80 mg to 240 mg/day for 3 to 6 weeks according to a dose titration schedule. The primary endpoint was clinical response (response according to RECIST 1.1 or stable disease with improvement of cutaneous lesions) in at least three patients. Exploratory objectives included histologic response (>30% decrease in Ki-67), FDG PET response, and ß-receptor expression levels. RESULTS: Fourteen patients were enrolled. The median duration of treatment was 26 days (range 21-42 days). The median highest propranolol dose was 160 mg/day (range 80 - 240 mg). Two patients showed clinical response (14%, 95% CI 3-100%). One of these patients showed a partial metabolic response on PET-CT. None of the tumors showed histologic response. The most common adverse event was grade 1/2 bradycardia (86%). There were no grade ≥ 3 adverse events. ADRB2 was overexpressed in 16 out of 18 tumors, in both responders and non-responders. None of the tumors showed ADRB1 overexpression. CONCLUSIONS: This window-of-opportunity trial did not show clinical efficacy of propranolol monotherapy. However, two out of 14 patients did show clinical benefit. ADRB1/2 expression did not correlate with clinical response.

ß-Receptor blocker enhances the anabolic effect of PTH after osteoporotic fracture.

The autonomic nervous system plays a crucial role in regulating bone metabolism, with sympathetic activation stimulating bone resorption and inhibiting bone formation. We found that fractures lead to increased sympathetic tone, enhanced osteoclast resorption, decreased osteoblast formation, and thus hastened systemic bone loss in ovariectomized (OVX) mice. However, the combined administration of parathyroid hormone (PTH) and the ß-receptor blocker propranolol dramatically promoted systemic bone formation and osteoporotic fracture healing in OVX mice. The effect of this treatment is superior to that of treatment with PTH or propranolol alone. In vitro, the sympathetic neurotransmitter norepinephrine (NE) suppressed PTH-induced osteoblast differentiation and mineralization, which was rescued by propranolol. Moreover, NE decreased the PTH-induced expression of Runx2 but enhanced the expression of Rankl and the effect of PTH-stimulated osteoblasts on osteoclastic differentiation, whereas these effects were reversed by propranolol. Furthermore, PTH increased the expression of the circadian clock gene Bmal1, which was inhibited by NE-ßAR signaling. Bmal1 knockdown blocked the rescue effect of propranolol on the NE-induced decrease in PTH-stimulated osteoblast differentiation. Taken together, these results suggest that propranolol enhances the anabolic effect of PTH in preventing systemic bone loss following osteoporotic fracture by blocking the negative effects of sympathetic signaling on PTH anabolism.