Beta-adrenergic receptor blockers. Adverse effects and drug interactions

Physiological effects of ivabradine in heart failure and beyond

Ivabradine is a pharmacologic agent that inhibits the funny current responsible for determining heart rate in the sinoatrial node. Ivabradine's clinical potential has been investigated in the context of heart failure since it is associated with reduced myocardial oxygen demand, enhanced diastolic filling, stroke volume, and coronary perfusion time; however, it is yet to demonstrate definitive mortality benefit. Alternative effects of ivabradine include modulation of the renin-angiotensin-aldosterone system, sympathetic activation, and endothelial function. Here, we review key clinical trials informing the clinical use of ivabradine and explore opportunities for leveraging its potential pleiotropic effects in other diseases, including treatment of hyperadrenergic states and mitigating complications of COVID-19 infection.

Elucidation of the Molecular Mechanism of Compound Danshen Dripping Pills against Angina Pectoris based on Network Pharmacology and Molecular Docking

BACKGROUND

Compound Danshen dripping pills (CDDP), a traditional Chinese medicine, has had an extensive application in the treatment of angina pectoris (AP) in China. However, research on the bioactive ingredients and underlying mechanisms of CDDP in AP remains unclear.

OBJECTIVE

In the present study, we explored the major chemical components and potential molecular mechanisms linked to the anti-angina effects of CDDP through the application of network pharmacology and molecular docking.

METHODS

The potential targets of active ingredients in CDDP were sourced from the Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) and the Swiss Target Prediction Database (STPD). Additionally, targets related to angina pectoris (AP) were retrieved from various databases, including Gene Cards, DisGeNET, Dis Genet, the Drug Bank database (DBD), and the Therapeutic Target Database (TDD). Protein- protein interaction networks were also established, and core targets were identified based on their topological significance. GO enrichment analysis and KEGG pathway analysis were conducted using the R software. Interactions between active ingredients and potential targets selected through the above process were investigated through molecular docking.

RESULTS

Seventy-six active ingredients were selected with the following criteria: OB ≥ 30%, DL ≥ 0.18. 383 targets of CDDP and 1488 targets on AP were gathered, respectively. Afterwards, 194 common targets of CDDP and anti-AP targets were defined, of which 12 were core targets. GO enrichment analysis indicated that CDDP acted on AP by response to lipopolysaccharide, regulating the reactive oxygen species and metal ion metabolism, and epithelial cell proliferation. In addition, KEGG enrichment analysis indicated that the signaling pathways were notably enriched in lipid and atherosclerosis, fluid shear stress and atherosclerosis, IL-17 signaling pathway, EGFR tyrosine kinase inhibitor resistance, PI3K-Akt signaling pathway, and TNF signaling pathway. Moreover, the molecular docking manifested excellent binding capacity between the active ingredients and targets on AP.

CONCLUSION

This study comprehensively illustrated the bioactive, potential targets, and molecular mechanisms of CDDP against AP, offering fresh perspectives into the molecular mechanisms of CDDP in preventing and treating AP.

Assessing the Risk of Hypoglycemia Secondary to Propranolol Therapy for the Treatment of Supraventricular Tachycardia in Infants

Supraventricular tachycardia (SVT) is the most common arrhythmia among infants. Prevention of SVT is frequently managed through propranolol therapy. Hypoglycemia is a known adverse effect of propranolol therapy, but little research has been done on the incidence and risk of hypoglycemia in treatment of SVT in infants with propranolol. This study attempts to offer insight into the risk of hypoglycemia associated with propranolol therapy when treating infantile SVT to help inform future glucose screening guidelines. We conducted a retrospective chart review of infants treated with propranolol in our hospital system. Inclusion criteria were infants < 1 year of age who received propranolol for the treatment of SVT. A total of 63 patients were identified. Data was collected on sex, age, race, diagnosis, gestational age, nutrition source (Total Parenteral Nutrition (TPN) vs oral), weight (kg), weight for length (kg/cm), propranolol dose (mg/kg/day), comorbidities, and whether or not a hypoglycemic event was identified (< 60 mg/dL). Hypoglycemic events were identified in 9/63 (14.3%) patients. Of the patients with hypoglycemic events, 9/9 (88.9%) had comorbid conditions. Patients with hypoglycemic events had significantly lower weight and propranolol dose than those without hypoglycemic events. Weight for length also tended to increase risk for hypoglycemic events. The high incidence of comorbid conditions in the patients who had hypoglycemic events suggests that hypoglycemic monitoring may only be necessary in patients with conditions predisposing to hypoglycemia.

Hemodynamic and Rhythmologic Effects of Push-Dose Landiolol in Critical Care-A Retrospective Cross-Sectional Study

BACKGROUND

The highly β1-selective beta-blocker Landiolol is known to facilitate efficient and safe rate control in non-compensatory tachycardia or dysrhythmia when administered continuously. However, efficacy and safety data of the also-available bolus formulation in critically ill patients are scarce.

METHODS

We conducted a retrospective cross-sectional study on a real-life cohort of critical care patients, who had been treated with push-dose Landiolol due to sudden-onset non-compensatory supraventricular tachycardia. Continuous hemodynamic data had been acquired via invasive blood pressure monitoring.

RESULTS

Thirty patients and 49 bolus applications were analyzed. Successful heart rate control was accomplished in 20 (41%) cases, rhythm control was achieved in 13 (27%) episodes, and 16 (33%) applications showed no effect. Overall, the heart rate was significantly lower (145 (130-150) vs. 105 (100-125) bpm, p < 0.001) in a 90 min post-application observational period in all subgroups. The median changes in blood pressure after the bolus application did not reach clinical significance. Compared with the ventilation settings before the bolus application, the respiratory settings including the required FiO2 after the bolus application did not differ significantly. No serious adverse events were seen.

CONCLUSIONS

Push-dose Landiolol was safe and effective in critically ill ICU patients. No clinically relevant impact on blood pressure was noted.

Design and rationale of randomized evaluation of decreased usage of beta-blockers after acute myocardial infarction (REDUCE-AMI)

AIMS

Most trials showing benefit of beta-blocker treatment after myocardial infarction (MI) included patients with large MIs and are from an era before modern biomarker-based MI diagnosis and reperfusion treatment. The aim of the randomized evaluation of decreased usage of beta-blockers after acute myocardial infarction (REDUCE-AMI) trial is to determine whether long-term oral beta-blockade in patients with an acute MI and preserved left ventricular ejection fraction (EF) reduces the composite endpoint of death of any cause or recurrent MI.

METHODS AND RESULTS

It is a registry-based, randomized, parallel, open-label, multicentre trial performed at 38 centres in Sweden, 1 centre in Estonia, and 6 centres in New Zealand. About 5000 patients with an acute MI who have undergone coronary angiography and with EF ≥ 50% will be randomized to long-term treatment with beta-blockade or not. The primary endpoint is the composite endpoint of death of any cause or new non-fatal MI. There are several secondary endpoints, including all-cause death, cardiovascular death, new MI, readmission because of heart failure and atrial fibrillation, symptoms, functional status, and health-related quality of life after 6-10 weeks and after 1 year of treatment. Safety endpoints are bradycardia, AV-block II-III, hypotension, syncope or need for pacemaker, asthma or chronic obstructive pulmonary disease, and stroke.

CONCLUSION

The results from REDUCE-AMI will add important evidence regarding the effect of beta-blockers in patients with MI and preserved EF and may change guidelines and clinical practice.

The Role of Beta-Adrenergic Receptors in Depression and Resilience

Norepinephrine is a catecholamine neurotransmitter that has been extensively implicated in the neurobiology of major depressive disorder (MDD). An accumulating body of evidence indicates that investigations into the action of norepinephrine at the synaptic/receptor level hold high potential for a better understanding of MDD neuropathology and introduce possibilities for developing novel treatments for depression. In this review article, we discuss recent advances in depression neuropathology and the effects of antidepressant medications based on preclinical and clinical studies related to beta-adrenergic receptor subtypes. We also highlight a beta-3 adrenergic receptor-involved mechanism that promotes stress resilience, through which antidepressant efficacy is achieved in both rodent models for depression and patients with major depression-an alternative therapeutic strategy that is conceptually different from the typical therapeutic approach in which treatment efficacy is achieved by reversing pathological alterations rather than by enhancing a good mechanism such as natural resilience. Altogether, in this review, we systematically describe the role of beta-adrenergic receptors in depression and stress resilience and provide a new avenue for developing a conceptually innovative treatment for depression.

Targeting tumor innervation: premises, promises, and challenges

A high intratumoral nerve density is correlated with poor survival, high metastasis, and high recurrence across multiple solid tumor types. Recent research has revealed that cancer cells release diverse neurotrophic factors and exosomes to promote tumor innervation, in addition, infiltrating nerves can also mediate multiple tumor biological processes via exosomes and neurotransmitters. In this review, through seminal studies establishing tumor innervation, we discuss the communication between peripheral nerves and tumor cells in the tumor microenvironment (TME), and revealed the nerve-tumor regulation mechanisms on oncogenic process, angiogenesis, lymphangiogenesis, and immunity. Finally, we discussed the promising directions of ‘old drugs newly used’ to target TME communication and clarified a new line to prevent tumor malignant capacity.

Severe hypoglycemia in propranolol treatment for infantile hemangiomas

BACKGROUND

Infantile hemangioma (IH), formerly termed strawberry hemangioma, is a benign vascular tumor caused by capillary endothelial cell proliferation. The tumor regresses after 1 year of age, but sequelae occur in approximately half of the patients without systemic treatment. Propranolol (PPL) is currently the first-line therapeutic agent in Japan as well as in Western countries. It is not commonly known that PPL may induce severe hypoglycemia, in addition to cardiovascular and respiratory side effects.

METHODS

We retrospectively analyzed patients with severe PPL-induced hypoglycemia in the 3 years since the launch of Hemangiol®, a PPL preparation specific for IH, in Japan in 2016.

RESULTS

The incidence of severe hypoglycemia and of hypoglycemic convulsions following PPL treatment was estimated to be 0.54% and 0.35%, respectively. The incidence of hypoglycemic convulsions appeared to be higher in Japan than in Western countries. Severe hypoglycemia was common in infants aged >1 year, when PPL was used for ≥6 months. Severe hypoglycemia often develops from 05:00 a.m. to 09:00 a.m. and is frequently associated with prolonged periods of fasting, poor feeding, or poor physical conditions.

CONCLUSION

To avoid the risk of hypoglycemia, the treatment should be initiated by 6 months of age during the proliferative phase at the latest, and should not be extended indiscriminately beyond 1 year of age. Guardians should be advised not to administer PPL on an empty stomach, in the presence of poor feeding, or who are in poor physical condition, not to prolong fasting after PPL administration, and to monitor the child's condition immediately after he or she wakes up.

Peculiarities of Adverse Events Manifested by Injury of Skin and Skin Derivatives and Associated with Beta-blockers Use

More than 50 years after Propranolol was introduced to the pharmaceutical market as a drug that can lower the heart rate, beta-blockers (BAB) are still widely used in the pharmacotherapy of cardiovascular diseases. However, the use of BAB has a number of limitations, first of all, due to adverse drug events (AE) that develop during their use. The purpose of our review was to study the features of the BAB AE manifested by injuries of the skin and its appendages. The clinical manifestations of them are the development or exacerbation of psoriasis, lichen planus, contact dermatitis, acrocyanosis, Raynaud's disease, alopecia, hyperhidrosis, vitiligo, anaphylaxis, and allergic skin reactions. True medicinal psoriasis occurs in patients taking BAB with no family or previous history and most often mimics erythrodermic psoriasis and palmar-plantar pustular psoriasis. Systemic use of BAB can also be accompanied by exacerbation of vitiligo. In patients with segmental vitiligo, the results of Doppler flowmetry and iontophoresis showed increased blood flow in vitiligo foci compared with normal skin. The development of anaphylactic reactions against the background of BAB therapy may be due to the modulation of adenylate cyclase, which can affect the release of anaphylactogenic mediators, as well as a decrease in the severity of cardiovascular compensatory changes. The peculiarities of the development of such reactions may be the resistance of patients to traditional treatment, which is due to the development of paradoxical reflex vagotonic effects when using adrenaline. Some of the mentioned AE may pose a potential threat to the life and health of the patient and therefore require additional discussion.

Towards Drug Repurposing in Cancer Cachexia: Potential Targets and Candidates

As a multifactorial and multiorgan syndrome, cancer cachexia is associated with decreased tolerance to antitumor treatments and increased morbidity and mortality rates. The current approaches for the treatment of this syndrome are not always effective and well established. Drug repurposing or repositioning consists of the investigation of pharmacological components that are already available or in clinical trials for certain diseases and explores if they can be used for new indications. Its advantages comparing to de novo drugs development are the reduced amount of time spent and costs. In this paper, we selected drugs already available or in clinical trials for non-cachexia indications and that are related to the pathways and molecular components involved in the different phenotypes of cancer cachexia syndrome. Thus, we introduce known drugs as possible candidates for drug repurposing in the treatment of cancer-induced cachexia.

A MULTIFACTORIAL APPROACH FOR IMPROVING THE SURGICAL PERFORMANCE OF NOVICE VITREORETINAL SURGEONS

PURPOSE

To quantitatively analyze and compare the novice vitreoretinal surgeons' performance after various types of external exposures.

METHODS

This prospective, self-controlled, cross-sectional study included 15 vitreoretinal fellows with less than 2 years of experience. Surgical performance was assessed using the Eyesi simulator after each exposure: Day 1, placebo, 2.5, and 5 mg/kg caffeine; Day 2, placebo, 0.2, and 0.6 mg/kg propranolol; Day 3, baseline simulation, breathalyzer reading of 0.06% to 0.10% and 0.11% to 0.15% blood alcohol concentration; Day 4, baseline simulation, push-up sets with 50% and 85% repetition maximum; Day 5, 3-hour sleep deprivation. Eyesi-generated total scores were the main outcome measured (0-700, worst to best).

RESULTS

Performances worsened after increasing alcohol exposure based on the total score (χ2 = 7; degrees of freedom = 2; P = 0.03). Blood alcohol concentration 0.06% to 0.10% and 0.11% to 0.15% was associated with diminished performance compared with improvements after propranolol 0.6 and 0.2 mg/kg, respectively (∆1 = -22 vs. ∆2 = +13; P = 0.02; ∆1 = -43 vs. ∆2 = +23; P = 0.01). Propranolol 0.6 mg/kg was positively associated with the total score, compared with deterioration after 2.5 mg/kg caffeine (∆1 = +7 vs. ∆2 = -13; P = 0.03).

CONCLUSION

Surgical performance diminished dose dependently after alcohol. Caffeine 2.5 mg/kg was negatively associated with dexterity, and performance improved after 0.2 mg/kg propranolol. No changes occurred after short-term exercise or acute 3-hour sleep deprivation.

The Use of β-Blockers in Heart Failure with Reduced Ejection Fraction

Treatment with β-blockers is the main strategy for managing patients with heart failure and reduced ejection fraction because of their ability to reverse the neurohumoral effects of the sympathetic nervous system, with consequent prognostic and symptomatic benefits. However, to date, they are underused, mainly because of the misconception that hypotension and bradycardia may worsen the haemodynamic status of patients with HFrEF and because of the presence of comorbidities falsely believed to be absolute contraindications to their use. To promote proper use of β-blockers in this article, we review the clinical pharmacology of β-blockers, the evidence of the beneficial effects of these drugs in heart failure with reduced ejection fraction, and the current guidelines for their use in clinical practice and in the presence of comorbidities (e.g., pulmonary disease, diabetes, atrial fibrillation, peripheral arterial disease, etc.). It is hoped that the practical approach discussed in this review will allow for a proper diffusion of knowledge about the correct use of β-blockers and the drug-disease interactions to achieve their increased use and titration, as well as for the selection of a specific agent with a view to a properly tailored approach for HFrEF patients.

Comparison of Effect of Nebivolol and Bisoprolol on Sexual Function of Hypertensive Female Patients

Introduction

Male and female sexual dysfunction is frequently found in patients with hypertension. Many studies indicate that this is found more frequently in patients treated with beta-blockers rather than due to hypertension itself; however, almost all studies have been done on male population. This study aims to study the effect of two commonly used beta-blockers on sexual function of a hypertensive female patient.

Methods

This two-arm open-label randomized prospective study was conducted from April 1, 2019 to March 30, 2020 in a tertiary care hospital at Pakistan. One hundred and fifty participants randomized to group A were given nebivolol 5 mg once daily in addition to their current hypertensive treatment. Another 150 participants randomized to group B were given bisoprolol 5 mg once daily in addition to their hypertensive therapy. Sexual function was assessed on day 0 and day 90 using female sexual function index (FSFI).

Results

The mean sexual score in the nebivolol group significantly improved after day 90 in comparison to day 0 (24.16 ± 2.1 vs. 26.91 ± 2.6; p-value < 0.0001), while no difference in sexual score in bisoprolol group after day 90 was observed (24.14 ± 2.1 vs. 24.12 ± 2.0; p-value = 0.91).

Conclusion

In this study, nebivolol group was associated with a significant improvement in sexual function. This can be due to additional vasodilation properties and a low risk of sexual side effects associated with nebivolol.

Nocturnal Arrhythmias and Heart-Rate Swings in Patients With Obstructive Sleep Apnea Syndrome Treated With Beta Blockers

Background

The higher cardiovascular variability and the increased prevalence of arrhythmias in patients with obstructive sleep apneas may contribute to their higher rate of fatal events during sleep. In this regard, the use of beta blockers (BB) is debated because they may induce bradyarrhythmias and alter the pattern of heart rate changes induced by apneas. Thus, the aim of our study is to quantify peri‐apneic heart‐rate swings and prevalence of nocturnal bradyarrhythmias in BB‐treated and BB‐naïve patients with obstructive sleep apnea.

Methods and Results

Our real‐life, retrospective, cohort study analyzed data from patients with obstructive sleep apnea after a basal cardiorespiratory polysomnography. Among 228 eligible participants, we enrolled 78 BB‐treated and 88 BB‐naïve patients excluding those treated with antiarrhythmic drugs or pacemakers, or with uninterpretable ECG traces during polysomnography. In each patient, type and frequency of arrhythmias were identified and peri‐apneic changes of RR intervals were evaluated for each apnea. BB‐treated patients were older and with more comorbidities than BB‐naïve patients, but had similar obstructive sleep apnea severity, similar frequency of arrhythmic episodes, and similar prevalence of bradyarrhythmias. Apnea‐induced heart‐rate swings, unadjusted for age, showed lower RR interval changes in BB‐treated (133.5±63.8 ms) than BB‐naïve patients (171.3±87.7 ms, P=0.01), lower RR interval increases during apneas (58.5±28.5 versus 74.6±40.2 ms, P=0.01), and lower RR interval decreases after apneas (75.0±42.4 versus 96.7±55.5 ms, P<0.05).

Conclusions

BB appear to be safe in patients with obstructive sleep apnea because they are not associated with worse episodes of nocturnal bradyarrhythmias and even seem protective in terms of apnea‐induced changes of heart rate.

Polyunsaturated fatty acid-derived IKs channel activators shorten the QT interval ex-vivo and in-vivo

AIM

We aimed to assess the ability of natural and modified polyunsaturated fatty acids (PUFAs) to shorten QT interval in ex-vivo and in-vivo guinea pig hearts.

METHODS

The effect of one natural (docosahexaenoic acid [DHA]) and three modified (linoleoyl glycine [Lin-GLY], docosahexaenoyl glycine [DHA-GLY], N-arachidonoyl taurine [N-AT]) PUFAs on ventricular action potential duration (APD) and QT interval was studied in a E4031 drug-induced long QT2 model of ex-vivo guinea pig hearts. The effect of DHA-GLY on QT interval was also studied in in-vivo guinea pig hearts upon intravenous administration. The effect of modified PUFAs on IKs was studied using Xenopus laevis oocytes expressing human KCNQ1 and KCNE1.

RESULTS

All tested PUFAs shortened ADP and QT interval in ex-vivo guinea pig hearts, however, with different ability in restoring baseline APD/QT interval with specific modified PUFAs being most efficacious. Despite comparable ability in activating the human KCNQ1/KCNE1 channel, Lin-GLY was not as effective in shortening APD/QT interval as DHA-GLY in ex-vivo hearts. By constructing a guinea pig-like KCNE1, we found Lin-GLY to induce less activating effect compared with DHA-GLY on human KCNQ1 co-expressed with guinea pig-like KCNE1. Docosahexaenoyl glycine was studied in more detail and was found to shorten QT interval in in-vivo guinea pig hearts.

CONCLUSION

Our results show that specific PUFAs shorten QT interval in guinea pig hearts. The tendency of modified PUFAs with pronounced IKs channel activating effect to better restore QT interval suggests that modifying PUFAs to target the IKs channel is a means to improve the QT-shortening effect.

High-fat diet feeding and palmitic acid increase CRC growth in β2AR-dependent manner

Epidemiology studies indicate that consumption of high-fat diet (HFD) is directly associated with the development of colorectal cancer (CRC). However, the exact component in HFD and the mechanism underlying its effect on CRC growth remained unclear. Our study shows that HFD feeding increases β2AR expression in the xenograft tissues of CRC-bearing mouse model; the elevated β2AR expression is reduced when HFD is replaced by control diet, which strongly suggests an association between HFD feeding and β2AR expression in CRC. HFD feeding increases palmitic acid and stearic acid levels in CRC; however, only palmitic acid increases β2AR expression, which is dependent upon Sp1. β2AR plays the dominant role in promoting CRC cell proliferation among all the β-AR subtypes. More importantly, knockout of β2AR or knockdown of Sp1 abolishes the palmitic acid increased CRC cell proliferation, suggesting palmitic acid increases CRC cell proliferation in β2AR-dependent manner. HFD or palmitic acid-rich diet (PAD) also fails to increase the tumor growth in xenograft mouse models bearing β2AR-knockout CRC cells. β2AR promotes CRC growth by increasing the phosphorylation of HSL at the residue S552. The phosphorylated and activated HSL (S552) changes the metabolic phenotype of CRC and increases energy production, which promotes CRC growth. Our study has revealed the unique tumorigenic properties of palmitic acid in promoting CRC growth, and have delineated the underlying mechanism of action. We are also the first to report the linkage between HFD feeding and β-adrenergic signaling pathway in relation to CRC growth.

The association between glaucoma and risk of depression: a nationwide population-based cohort study

Background

Previous cross-sectional studies revealed a higher prevalence of depression among glaucoma patients. However, cohort studies were in lack to build the risk of incident depression after the diagnosis of glaucoma. The aim of our study was to investigate the association between glaucoma and the subsequent risk of developing depression and to assess risk factors associated with depression in glaucoma patients.

Methods

A population-based retrospective cohort study using the Taiwan National Health Insurance Research Database was conducted from January 1, 2001 through December 31, 2011. Glaucoma patients (n = 8777) and age- and gender-matched control subjects without glaucoma (n = 35,108) were enrolled in the study. Kaplan-Meier curves were generated to compare the cumulative hazard of subsequent depression between the glaucoma and control groups. A Cox regression analysis estimated the crude and adjusted hazard ratios (HRs) for depression. Risk factors leading to depression were investigated among the glaucoma patients.

Results

Glaucoma patients had a significantly higher cumulative hazard of depression compared to the control group (p-value < 0.0001). The Cox regression model indicated that the glaucoma group had a significantly higher risk of depression (adjusted HR = 1.71). Within the glaucoma group, significant risk factors for depression included age, female, low income, substance abuse, and living alone. However, the use of β-blocker eye drops and the number of glaucoma medications were not significant risk factors for depression.

Conclusion

Patients with glaucoma are at significantly greater risk of developing depression. Among glaucoma patients, age, female, low income, substance abuse, and living alone were significant risk factors for depression.

Beta-blockers for prevention and treatment of retinopathy of prematurity in preterm infants

BACKGROUND

Retinopathy of prematurity (ROP) is a vision-threatening disease of preterm neonates. The use of beta-adrenergic blocking agents (beta-blockers), which modulate the vasoproliferative retinal process, may reduce the progression of ROP or even reverse established ROP.

OBJECTIVES

To determine the effect of beta-blockers on short-term structural outcomes, long-term functional outcomes, and the need for additional treatment, when used either as prophylaxis in preterm infants without ROP, stage 1 ROP (zone I), or stage 2 ROP (zone II) without plus disease or as treatment in preterm infants with at least prethreshold ROP.

SEARCH METHODS

We searched the Cochrane Neonatal Review Group Specialized Register; CENTRAL (in the Cochrane Library Issue 7, 2017); Embase (January 1974 to 7 August 2017); PubMed (January 1966 to 7 August 2017); and CINAHL (January 1982 to 7 August 2017). We checked references and cross-references and handsearched abstracts from the proceedings of the Pediatric Academic Societies Meetings.

SELECTION CRITERIA

We considered for inclusion randomised or quasi-randomised clinical trials that used beta-blockers for prevention or treatment of ROP in preterm neonates of less than 37 weeks' gestational age.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane and the Cochrane Neonatal Review Group. We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

We included three randomised trials (N = 366) in this review. Two of these studies were at high risk of bias. All studies reported on prevention of ROP and compared oral propranolol with placebo or no treatment. We found no trials assessing beta-blockers in infants with established stage 2 or higher ROP with plus disease.In one trial, study medication was started after one week of life, i.e. prior to the first ROP screening. The other two trials included preterm infants if they had stage 2 or lower ROP without plus disease. Based on the GRADE assessment, we considered evidence to be of low quality for the following outcomes: rescue treatment with anti-VEGF or laser therapy; and arterial hypotension or bradycardia requiring inotropic support. Evidence was of moderate quality for the following outcomes: progression to stage 2 with plus disease; progression to stage 3 ROP; and progression to stage 4 or 5 ROP.Meta-analysis of three trials (N = 366) suggested beneficial effects of oral beta-blockers on the risk of requiring anti-VEGF agents (typical risk ratio (RR) 0.32, 95% confidence interval (CI) 0.12 to 0.86; I² = 0%; typical risk difference (RD) -0.06, 95% CI -0.10 to -0.01; I² = 75%; number needed to treat for an additional beneficial outcome (NNTB) 18, 95% CI 14 to 84) and laser therapy (typical RR 0.54, 95% CI 0.32 to 0.89; typical RD -0.09, 95% CI -0.16 to -0.02; I² = 31%; NNTB 12, 95% CI 8 to 47). Meta-analysis of two trials (N = 161) demonstrated a beneficial effect of oral beta-blockers on progression to stage 3 ROP (typical RR 0.60, 95% CI 0.37 to 0.96; I² = 0%; typical RD -0.15, 95% CI -0.28 to -0.02; I² = 73%; NNTB 7, 95% CI 5 to 67). There was no significant effect of oral beta-blockers on progression to stage 2 ROP with plus disease or to stage 4 or 5 ROP. Although meta-analysis did not indicate a significant effect of beta-blockers on arterial hypotension or bradycardia, propranolol dosage in one study was reduced by 50% in infants of less than 26 weeks' gestational age due to severe hypotension, bradycardia, and apnoea in several participants. Analyses did not indicate significant effects of beta-blockers on complications of prematurity or mortality. None of the trials reported on long-term visual impairment.

AUTHORS' CONCLUSIONS

Limited evidence of low-to-moderate quality suggests that prophylactic administration of oral beta-blockers might reduce progression towards stage 3 ROP and decrease the need for anti-VEGF agents or laser therapy. The clinical relevance of those findings is unclear as no data on long-term visual impairment were reported. Adverse events attributed to oral propranolol at a dose of 2 mg/kg/d raise concerns regarding systemic administration of this drug for prevention of ROP at the given dose. There is insufficient evidence to determine the efficacy and safety of beta-blockers for prevention of ROP due to high risk of bias in two included trials and the lack of long-term functional outcomes. We would encourage researchers to conduct large, well-designed trials to confirm or refute the role of beta-blockers for prevention and treatment of ROP in preterm infants. Trials should report on long-term visual impairment. Researchers should consider dose-finding studies of systemic beta-blockers and topical administration of beta-blockers, in order to optimise drug delivery and minimise adverse events.

Identifying problematic drugs based on the characteristics of their targets

Identifying promising compounds during the early stages of drug development is a major challenge for both academia and the pharmaceutical industry. The difficulties are even more pronounced when we consider multi-target pharmacology, where the compounds often target more than one protein, or multiple compounds are used together. Here, we address this problem by using machine learning and network analysis to process sequence and interaction data from human proteins to identify promising compounds. We used this strategy to identify properties that make certain proteins more likely to cause harmful effects when targeted; such proteins usually have domains commonly found throughout the human proteome. Additionally, since currently marketed drugs hit multiple targets simultaneously, we combined the information from individual proteins to devise a score that quantifies the likelihood of a compound being harmful to humans. This approach enabled us to distinguish between approved and problematic drugs with an accuracy of 60–70%. Moreover, our approach can be applied as soon as candidate drugs are available, as demonstrated with predictions for more than 5000 experimental drugs. These resources are available at http://sourceforge.net/projects/psin/.

Development of target-specific liposomes for delivering small molecule drugs after reperfused myocardial infarction

Although reperfusion is essential in restoring circulation to ischemic myocardium, it also leads to irreversible events including reperfusion injury, decreased cardiac function and ultimately scar formation. Various cell types are involved in the multi-phase repair process including inflammatory cells, vascular cells and cardiac fibroblasts. Therapies targeting these cell types in the infarct border zone can improve cardiac function but are limited by systemic side effects. The aim of this work was to develop liposomes with surface modifications to include peptides with affinity for cell types present in the post-infarct myocardium. To identify peptides specific for the infarct/border zone, we used in vivo phage display methods and an optical imaging approach: fluorescence molecular tomography (FMT). We identified peptides specific for cardiomyocytes, endothelial cells, myofibroblasts, and c-Kit + cells present in the border zone of the remodeling infarct. These peptides were then conjugated to liposomes and in vivo specificity and pharmacokinetics were determined. As a proof of concept, cardiomyocyte specific (I-1) liposomes were used to deliver a PARP-1 (poly [ADP-ribose] polymerase 1) inhibitor: AZ7379. Using a targeted liposomal approach, we were able to increase AZ7379 availability in the infarct/border zone at 24h post-injection as compared with free AZ7379. We observed ~3-fold higher efficiency of PARP-1 inhibition when all cell types were assessed using I-1 liposomes as compared with negative control peptide liposomes (NCP). When analyzed further, I-1 liposomes had 9-fold and 1.5-fold higher efficiencies in cardiomyocytes and macrophages, respectively, as compared with NCP liposomes. In conclusion, we have developed a modular drug delivery system that can be targeted to cell types of therapeutic interest in the infarct border zone.

Management of pregnancy in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoantibody-mediated systemic autoimmune disease, predominantly affecting young females. Pregnancy is increasingly common in the setting of SLE, as survival and quality of life of patients improve. Although live births can be achieved in the most cases, pregnancy in patients with SLE remains a high-risk condition. Maternal and fetal mortality and morbidity are considerably increased, compared with the general population. Aberrations in pregnancy-related maternal immune adaptations are likely contributors. Active maternal disease, renal involvement, specific autoantibody subsets and advanced organ damage are predictors of poor outcome. Therapeutic options are limited during pregnancy as maternal benefit has to be weighed against fetal risk. Prevention of preterm birth and refractory pregnancy loss, as well as management of established neonatal heart block remain unmet needs. Further research should address these important issues that affect young patients with SLE and their babies.

Hypertension in the elderly

The elderly are the most rapidly growing population group in the world. Data collected over a 30-year period have demonstrated the increasing prevalence of hypertension with age. The risk of coronary artery disease, stroke, congestive heart disease, chronic kidney insufficiency and dementia is also increased in this subgroup of hypertensives. Hypertension in the elderly patients represents a management dilemma to cardiovascular specialists and other practioners. During the last years and before the findings of the Systolic Hypertension in Europe Trial were published, the general medical opinion considered not to decrease blood pressure values similarly to other younger patients, in order to avoid possible ischemic events and poor oxygenation of the organs (brain, heart, kidney). The aim of this review article is to highlight the importance of treating hypertension in aged population in order to improve their quality of life and lower the incidence of the cardiovascular complications.

Isolated dynamic left ventricular outflow tract obstruction can cause hypotension that rapidly responds to intravenous beta blockade

Dynamic left ventricular outflow tract obstruction occurs in hypertrophic cardiomyopathy, stress cardiomyopathy, acute coronary syndromes, and with inotrope use. We describe three critical care patients who developed "isolated" left ventricular outflow tract obstruction with hypotension in the absence of these precipitants. Systolic anterior motion of anterior mitral valve leaflet with peak left ventricular outflow tract gradients of greater than 120 mmHg was noted in Cases 1 and 2. Under close supervision, intravenous (IV) β blocker was initiated with 5 mg metoprolol repeated every 5 minutes up to 15 mg and continued to maintain heart rate less than 70 beats/min. IV fluids were replaced aggressively. Bedside Doppler echocardiogram confirmed near normalization of left ventricular outflow tract gradient with improvement in systolic anterior motion and hypotension within minutes after IV β blocker confirming its specific therapeutic effect. Isolated left ventricular outflow tract obstruction can occur in the absence of recognized precipitants. Early recognition is crucial because this potentially fatal condition responds well to adequate β blocker and IV fluids with rapid relief of hypotension and symptoms.

Study protocol: safety and efficacy of propranolol in newborns with Retinopathy of Prematurity (PROP-ROP): ISRCTN18523491

Background

Despite new therapeutic approaches have improved the prognosis of newborns with retinopathy of prematurity (ROP), an unfavourable structural and functional outcome still remains high. There is high pressure to develop new drugs to prevent and treat ROP. There is increasing enthusiasm for anti-VEGF drugs, but angiogenic inhibitors selective for abnormal blood vessels would be considered as an optimal treatment.

In an animal experimental model of proliferative retinopathy, we have recently demonstrated that the pharmacological blockade of beta-adrenoreceptors improves retinal neovascularization and blood retinal barrier breakdown consequent to hypoxia. The purpose of this study is to evaluate the propranolol administration in preterm newborns suffering from a precocious phase of ROP in terms of safety and efficacy in counteracting the progression of retinopathy.

Methods/Design

Preterm newborns (gestational age at birth lower than 32 weeks) with stage 2 ROP (zone II-III without plus) will be randomized, according to their gestational age, to receive propranolol added to standard treatment (treatment adopted by the ETROP Cooperative Group) or standard treatment alone. Propranolol will be administered until retinal vascularization will be completely developed, but not more than 90 days. Forty-four participants will be recruited into the study. To evaluate the safety of propranolol administration, cardiac and respiratory parameters will be continuously monitored. Blood samplings will be performed to check renal, liver and metabolic balance. To evaluate the efficacy of propranolol, the progression of the disease, the number of laser treatments or vitrectomies, the incidence of retinal detachment or blindness, will be evaluated by serial ophthalmologic examinations. Visual function will be evaluated by means of behavioural standardized tests.

Discussion

This pilot study is the first research that explores the possible therapeutic role of beta blockers in ROP. The objective of this research is highly ambitious: to find a treatment simple, inexpensive, well tolerated and with few adverse effects, able to counteract one of the major complications of the prematurity. Any favourable results of this research could open new perspectives and original scenarios about the treatment or the prevention of this and other proliferative retinopathies.

Trial Registration

Current Controlled Trials ISRCTN18523491; ClinicalTrials.gov Identifier NCT01079715; EudraCT Number 2010-018737-21

S(-)Propranolol as a discriminative stimulus and its comparison to the stimulus effects of cocaine in rats

RATIONALE

Racemic propranolol (PRO), a beta-adrenoceptor antagonist, has been evaluated as a test agent but not as a discriminative stimulus. Its S(-) stereoisomer is thought to subserve the effects of (+/-)PRO.

MATERIALS AND METHODS

Rats were trained to discriminate S(-)PRO (5 mg/kg) from saline in a two-lever food-reinforced operant conditioning task.

RESULTS

The S(-)PRO stimulus was shown to be centrally mediated, dose-related, time dependent, and stereoselective: S(-)PRO (ED(50) = 2.2 mg/kg) was twice as potent as (+/-)PRO and approximately four times as potent as R(+)PRO. The S(-)PRO stimulus generalized fully to the beta-adrenoceptor agent pindolol, the alpha(1)-adrenoceptor agonist methoxamine, cocaine, and the serotonergic agents TFMPP and RU 24969; partial generalization occurred to (-)ephedrine and nisoxetine but not to fenfluramine or 5-OMe DMT. The S(-)PRO stimulus was blocked completely (and competitively) when prazosin, an alpha(1)-adrenoceptor antagonist, was given in combination with the training dose of S(-)PRO. Moreover, prazosin exerted antagonism of the S(-)PRO-like effect of (+/-)PRO or R(+)PRO but produced only partial antagonism of the S(-)PRO-like effect of cocaine. In a second study, rats were trained to discriminate 8 mg/kg of cocaine from saline. The cocaine stimulus generalized to S(-)PRO, (+/-)PRO, and R(+)PRO. Prazosin partially attenuated the stimulus effect of cocaine (8 mg/kg) but completely blocked the cocaine-like effects of (+/-), S(-), and R(+)PRO.

CONCLUSIONS

PRO and cocaine exhibited cross-substitution, but their stimulus effects were antagonized differentially by prazosin. PRO (and its optical isomers) can exert a stimulus effect that is based, at least in part, on increased alpha(1)-adrenoceptor activity. PRO might be better characterized as an adrenoceptor partial agonist.

Depression and anxiety in patients with pseudoexfoliative glaucoma

OBJECTIVE

This study aimed to determine whether patients with pseudoexfoliative glaucoma (PXG), associated with vascular disorders, have more depressive and anxiety symptoms than patients with primary open-angle glaucoma (POAG) and controls without glaucoma. The vascular depression model was tested in this study.

METHOD

The sample consisted of 41 PXG patients, 32 POAG patients and 40 controls. Each subject was diagnosed as having PXG or POAG or chosen as a control patient by an ophthalmologist and then evaluated by a psychiatrist. The Structured Clinical Interview for DSM-IV, Turkish version; Hamilton Depression Rating Scale (HDRS); Hamilton Anxiety Rating Scale (HARS); Mini Mental State Examination; and Montgomery-Asberg Depression Rating Scale (MADRS) were administered to all subjects.

RESULTS

The HDRS and MADRS scores of the PXG patients were significantly higher than those of the POAG and the control group (chi(2)=9.858, p=.007 and chi(2)=11.618, p=.003, respectively). The HARS scores did not show a significant difference between the patients with PXG or POAG and the control subjects (chi(2)=1.615, p=.446). In each of the three groups, there was no correlation between the HDRS, HARS or MADRS scores and any of the following parameters: duration of glaucoma, medical treatment, visual acuity, intraocular pressure, perimetric stage, cup-disc ratio and number of glaucoma operations (p>.05).

CONCLUSION

A relationship between PXG and severity of depressive symptoms was shown by our data. However, no significant difference could be found between the anxiety levels of the three groups.

β-Blockade and increased dyslipidemia in patients bearing Glu27 variant of β2 adrenergic receptor gene

In this study, the effects of polymorphisms of the beta(2) and beta(3) adrenergic receptor genes on the occurrence of dyslipidemia and diabetes mellitus in hypertensive patients treated with beta-blockers (atenolol or metoprolol) were evaluated. Patients who gave written informed consent were asked to return for blood sampling for estimation of serum glucose, total cholesterol, HDL, triglycerides and for genotype determination. Genotyping analysis was performed by PCR-RFLP assay. In patients bearing beta(2)AR Glu27 or the beta(3)AR Arg64 variant there was a larger occurrence of hypertriglyceridemia, alone or in combination with elevated cholesterol levels. Furthermore, the beta(2)AR Glu27 variant significantly associates with hypetriglyceridemia in a cumulative fashion. The risk to develop this side effect after beta-blockade was four-fold higher in patients homozygous for the beta(2)AR Glu27 variant as compared to beta(2)AR27Gln allele. This result allows the identification of patients at high risk to develop metabolic complications to chronic beta-blockade treatment.

[Antihypertensive drug-drug interactions]

A drug interaction is the quantitative or qualitative modification of the effect of a drug by the simultaneous or successive administration of a different one. Hypertensive patients, mainly the more elderly ones, frequently present concomitant diseases that require the administration of several medicines which facilitates the appearance of interactions. The lack of effectiveness of the antihypertensive treatment is a relatively frequent fact that sometimes is due to interactions of antihypertensive drugs with other treatments. It is difficult to determine the incidence of interactions, but it is related to the number of drugs administered simultaneously. Between 37 and 60% of hospital-admissions are treated with potentially dangerous drug associations and up to a 6% of fatal events are due to this circumstance. Among antihypertensive drugs, diuretics and angiotensin converting enzyme inhibitors are less affected by drug-interactions. Lipophilic beta-blockers agents may present some clinical relevant interactions, whereas calcium channel blockers, especially the non-dihydropiridinic ones, are implied in clinically relevant pharmacokinetic interactions. Among the angiotensin receptor blockers there are differences that would have to be considered when they are used in patients who receive other drugs. Although it is impossible for the doctor to remember all the clinical relevant interactions, it is important to bear in mind their existence and the possible mechanisms of production which can help to identify them and to contribute to their prevention. The most frequent interactions related with clinical problems are the pharmacokinetic ones, mainly those related to the metabolism through the cytochrome P450 system or the presystemic clearance by means of the P-glycoprotein. Enzymes of the cytochrome P450 system may present polymorphisms that can explain the individual differences in the response to drugs or the appearance of drug-interactions.

Trials in isolated systolic hypertension: an update

Isolated systolic hypertension (ISH) has proved to be a powerful predisposing factor for cardiovascular diseases in the elderly. Recent placebo-controlled interventional trials such as the Systolic Hypertension in the Elderly Program, the Systolic Hypertension in Europe, and the Systolic Hypertension in China showed that the lowering of systolic blood pressure using a diuretic- or a calcium antagonist-based treatment is associated with a decrease in cardiovascular events. Antihypertensive therapy was found especially effective in preventing stroke in the elderly with ISH. A slowing in the progression of dementia was observed in patients randomized to a calcium antagonist-based treatment. Patients at high cardiovascular risk such as those with diabetes benefited the most from treatment. In another trial performed in patients with left ventricular hypertrophy (Losartan Intervention For Endpoint Reduction), a subset of patients had ISH. In those patients, an angiotensin II antagonist-based treatment was superior to a b-blocker-based treatment in preventing cardiovascular complications. The experience accumulated in patients with ISH showed that combination therapy is often required to control blood pressure. Overall, the evidence available today indicates that pharmacologic treatment of ISH markedly improves the outcome of elderly patients.

Trials in isolated systolic hypertension: an update

Isolated systolic hypertension (ISH) has proved to be a powerful predisposing factor for cardiovascular diseases in the elderly. Recent placebo-controlled interventional trials such as the Systolic Hypertension in the Elderly Program (SHEP), the Systolic Hypertension in Europe (Syst-Eur), and the Systolic Hypertension in China (Syst-China) showed that the lowering of systolic blood pressure using a diuretic- or a calcium antagonist-based treatment is associated with a decrease in cardiovascular events. Antihypertensive therapy was found especially effective in preventing stroke in the elderly with ISH. A slowing in the progression of dementia was observed in patients randomized to a calcium antagonist-based treatment. Patients at high cardiovascular risk such as those with diabetes benefited the most from treatment. In another trial performed in patients with left ventricular hypertrophy (Losartan Intervention For Endpoint Reduction ), a subset of patients had ISH. In those patients, an angiotensin II antagonist-based treatment was superior to a b-blocker-based treatment in preventing cardiovascular complications. The experience accumulated in patients with ISH showed that combination therapy is often required to control blood pressure. Overall, the evidence available today indicates that pharmacologic treatment of ISH markedly improves the outcome of elderly patients.

Insulin resistance as an independent risk factor for carotid artery wall intima media thickening in vasospastic angina

Studies have shown the presence of insulin resistance together with compensatory hyperinsulinemia in vasospastic angina as well as obstructive coronary artery disease. There is growing evidence that the development of coronary atherosclerosis may be closely related to systemic atherosclerosis as well as coronary spasm. However, no information is available about the possible relationship between insulin resistance and the existence of carotid atherosclerosis in vasospastic angina without segmental stenosis or luminal irregularities in coronary angiograms. To evaluate the independent effect of insulin resistance on carotid intima media thickening, we performed insulin sensitivity tests (steady-state plasma glucose method) on 40 patients with vasospastic angina and 24 control subjects with angiographically intact coronary arteries. Both oral glucose tolerance tests and lipid analyses were performed. Using B-mode ultrasonography, we assessed intima media thickness and plaque formation of common carotid arteries in these subjects. The steady-state plasma glucose level in the vasospastic angina group was about twofold higher than that of the control group, confirming the presence of insulin resistance in patients with vasospastic angina. The patients with vasospastic angina showed a significant increase in the average intima media thickness of the carotid wall and frequency of plaque formation, although they were comparable to the control subjects in risk factors other than insulin resistance. The intima media thickness was correlated with age (r = .62, P < .001), 2-hour insulin area (r = .45, P < .01), and steady-state plasma glucose level (r = .68, P < .0001) in patients with vasospastic angina. Similar correlations were observed in the control subjects. Multiple regression analyses of data indicated that 67% of the variation in the intima media thickness could be accounted for by age, steady-state plasma glucose level, and cigarette-years in vasospastic angina. In addition, differences in IMT were independently related to vasospastic angina. These results suggest that insulin resistance in association with compensatory hyperinsulinemia may be an important pathogenic factor for the development of coronary artery spasms and systemic early atherosclerosis.

Role of insulin resistance associated with compensatory hyperinsulinemia in ischemic stroke

BACKGROUND AND PURPOSE

Although insulin resistance and hyperinsulinemia play a crucial role in the pathogenesis of atherosclerosis, little is known about their roles in ischemic stroke. The purpose of this study was to clarify whether insulin resistance and hyperinsulinemia are causative factors in the pathogenesis of ischemic stroke.

METHODS

Thirty-four consecutive patients with ischemic stroke, who were normotensive, nondiabetic, and not obese, were classified into three groups--atherothrombotic infarction (n = 16), lacunar infarction (n = 10), and cardioembolic infarction (n = 8)--based on clinical findings, brain imaging, and cerebral angiography. Both oral glucose tolerance tests and lipid analyses were performed. Insulin sensitivity was determined by the steady state plasma glucose method with the use of octreotide acetate. Data were compared with those of healthy control subjects (n = 15).

RESULTS

Steady state plasma glucose levels were significantly higher in the atherothrombotic infarction group compared with control subjects and the other two stroke groups, indicating the presence of insulin resistance in patients with atherothrombotic infarction. In the atherothrombotic infarction group, the 2-hour insulin area (area under the plasma insulin concentration curve) during a 75-g oral glucose tolerance test was significantly increased and dyslipidemic changes (increased triglyceride and apolipoprotein B, decreased high-density lipoprotein) were observed, whereas these changes were not found in the lacunar infarction and cardioembolic stroke groups.

CONCLUSIONS

Insulin resistance in association with compensatory hyperinsulinemia and dyslipidemia may be an important pathogenetic factor underlying the development of atherothrombotic infarction.

Insulin resistance associated with compensatory hyperinsulinemia as an independent risk factor for vasospastic angina

BACKGROUND

It is generally believed that coronary artery spasm plays an important role in the progression of obstructive coronary artery disease. Since insulin resistance together with hyperinsulinemia plays an important role in the pathogenesis of coronary atherosclerosis, we investigated the association of hyperinsulinemia and insulin resistance with vasospastic angina (VAP).

METHODS AND RESULTS

The study population consisted of 60 patients with VAP and 42 control subjects (62 subjects with normal glucose tolerance and 40 with impaired glucose tolerance). Insulin sensitivity was determined by the steady-state plasma glucose (SSPG) method for nondiabetic, normotensive, nonobese subjects (16 control subjects, 16 obstructive coronary artery disease patients, and 16 VAP patients). Compared with the control group, the 2-hour insulin area (area under the plasma insulin concentration-time curve) during a 75-g oral glucose tolerance test was significantly higher in both VAP groups with normal and impaired glucose tolerance. A high frequency of vasospastic angina was observed in subjects with clustered risk factors for insulin resistance syndrome, suggesting a close association of VAP with this syndrome. In stepwise discriminant analysis, the 2-hour insulin area was significantly associated with VAP independent of other risk factors. SSPG level in VAP was about twofold over control, indicating the presence of insulin resistance in patients with VAP. However, no differences were found between patients with VAP and obstructive coronary artery disease with respect to mean SSPG level.

CONCLUSIONS

SSPG level was significantly elevated in patients with VAP and obstructive coronary artery disease compared with control subjects. This indicates that hyperinsulinemia is secondary to insulin resistance, both of which are thought to play important roles as risk factors for VAP in the early atheromatous lesion and in the future development of occlusive lesions when chronically present.

Antihypertensive therapy targeted to the needs of the patient: focus on the renin-angiotensin system; older and newer agents

Antihypertensive drug therapy can lower blood pressure and prolong life, but many hypertensive patients continue to develop further risk factors and to die prematurely of heart disease. Antihypertensive drugs can also interfere with the patient's quality of life, and many are not compatible with the concomitant medical conditions of the patient and the medications taken to treat them. For these reasons, the antihypertensive therapy selected should meet the specific and complete needs of each patient, not just treat the high blood pressure. An analysis of the drugs that inhibit the renin-angiotensin system suggests that several of these drugs have a more favorable therapeutic profile than other classes of hypotensive agents. The newly developed receptor-site-specific blockers are expected to be tolerated better by hypertensive patients and, consequently, to enhance their quality of life. The first of the new class of nonpeptide blockers of the AT1 receptor, losartan--which has no partial agonist activity--is likely to have the advantages of the angiotensin-converting enzyme inhibitors without their adverse effects, notably cough. In selected patients, the AT1-receptor blockers could become the drugs of first choice for the management of hypertension.

Bisoprolol, a once-a-day beta-blocking agent for patients with mild to moderate hypertension

The 24-h blood pressure control of bisoprolol, a new beta-selective, beta-blocking agent, was studied in 240 mild to moderate hypertensive patients in this 4-week, randomized, double-blind, placebo-controlled trial. A once-daily dosing schedule was evaluated by comparing bisoprolol's antihypertensive effectivness and safety at 24 h postdose and 3 h postdose, the latter time intended to correspond to peak effectiveness. Results from this trial demonstrated the antihypertensive effectiveness of once-daily bisprolol at doses ranging from 5-20 mg. Mean reductions from baseline diastolic blood pressure, measured 24 h postdose, were 6.3, 8.8, and 10.1 mmHg for patients receiving bisoprolol 5, 10, and 20 mg, respectively, compared with 1.6 mmHg for placebo-treated patients (p < 0.01); mean reductions from baseline systolic blood pressure for the bisoprolol groups were 8.6, 8.6, and 10.9 mmHg, respectively, versus 3.3 mmHg for placebo (p < or = 0.01); and mean reductions from baseline heart rate for the bisoprolol groups were 5.1, 7.1, and 10.2 beats/min, respectively, compared with a 0.9 beats/min increase in heart rate for the placebo group (p < 0.01). The response rates for bisoprolol-treated patients ranged from 47 to 70% compared with 18% for patients on placebo (p < 0.01). Antihypertensive effects were dose-related and sustained over the 24-h dosing interval. Near maximal antihypertensive effects were achieved within 1 week of initiation of therapy with bisoprolol and were sustained over the course of the trial.(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin resistance--not hyperinsulinemia--is pathogenic in essential hypertension

A correlation between essential hypertension and insulin resistance/hyperinsulinemia is well documented, and there is adequate reason to believe that this association is causal. The common presumption that hyperinsulinemia mediates this connection is based on studies demonstrating various pressor effects of insulin, such as sodium retention, activation of the sympathetic nervous system, and stimulation of renin output. However, a consideration of physiological parameters in essential hypertensives indicates that these insulin-mediated pressor effects are unlikely to play a crucial pathogenic role in most cases of essential hypertension. Moreover, physiological elevation of insulin following a meal is typically associated with a reduction of blood pressure in hypertensives and the elderly. Euglycemic insulin clamps tend to reduce blood pressure in elderly subjects, and prolonged maintenance of hyperinsulinemia in animals does not raise blood pressure. In fact, insulin has long been known to have direct vasodilatory or antipressor effects on resistance vessels, and there is recent evidence that insulin reduces vascular resistance in skeletal muscles to facilitate glycogen storage after a meal. I propose that essential hypertensives experience a net deficit of insulin activity in vascular muscle, and that, in conjunction with other genetic or acquired defects of electrolyte transport, this leads to an increase in basal vascular tone and a hypersensitivity to pressor agents. Correction of insulin resistance usually aids blood pressure control, and in addition may mitigate the excess cardiovascular risk associated with hypertension.

The effects of various antihypertensive agents on cardiovascular risk factors in patients with renal failure

Systemic cardiovascular diseases are the most important cause of morbidity and mortality among patients with chronic renal failure. Hypertension, lipid-profile abnormalities, glucose intolerance, and left ventricular hypertrophy are found in most patients with chronic renal failure and are responsible for the increased incidence of atherosclerosis. Hypertension is the risk factor most susceptible to treatment, but consideration must be given in selecting an antihypertensive agent not only to its effect on blood pressure but to its effects on the other risk factors. Improper selection could impair the long-term benefit of good blood pressure control by increasing the severity of the other cardiovascular risk factors and eventually worsening the prognosis of the chronic renal failure. The remaining renal function in patients not yet in end-stage renal failure deserves special consideration; an adequate antihypertensive regimen could potentially delay the need for dialysis.

Contraindications to vasoconstrictors in dentistry: Part III. Pharmacologic interactions

This article discusses the relative contraindications to the use of vasoconstrictor in patients currently medicated with tricyclic antidepressants, monoamine oxidase inhibitors, phenothiazines and beta-blockers. It reviews drug interactions and emphasizes potential detrimental systemic effects that epinephrine contained in local anesthetics can have when administered concomitantly with these drugs. Finally, special considerations are expressed concerning patients who abuse illicit drugs such as cocaine.

Around the beta-blockers, one more time

We review the pharmacology, pharmacokinetics, and relative costs of beta-blockers, as well as indications for and therapeutic controversies surrounding their use. It is hoped that this discussion will assist clinicians in making informed decisions when choosing a drug for a hospital formulary or a particular patient. Beta-blockers are indicated for a variety of noncardiovascular and cardiovascular conditions, including hypertension, ischemic heart disease, arrhythmias, and prophylaxis of myocardial infarction (MI). These agents compete with catecholamines at beta-adrenoreceptors. They have different ancillary properties, including intrinsic sympathomimetic activity (ISA), cardioselectivity, and membrane stabilizing-activity, and vary in their duration of action, route of elimination, and lipophilicity. Beta-blocking agents decrease oxygen demand by exerting a negative inotropic and chronotropic effect. They also reduce blood pressure and possess antiarrhythmic effects. Beta-blockers penetrate the central nervous system (CNS) to different degrees and can cause a wide variety of CNS adverse effects. Nonselective beta-blockers have been noted to slightly reduce renal blood flow. Nadolol is an exception in that either no change, or even a small increase in renal blood flow, is observed upon initiation of therapy. Beta-blockers also act on the pulmonary bed by preventing beta 2-mediated bronchodilation, thereby exacerbating bronchospastic disease in some patients. Beta-adrenergic blocking agents can potentiate both hypoglycemia and hyperglycemia in diabetic patients. Their effects on total peripheral resistance (TPR) are controversial. Initially it appears that beta-blockade increases TPR. After chronic therapy, however, TPR decreases to or below baseline values. These agents appear to be equally efficacious in the treatment of hypertension, arrhythmias, and ischemic heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Celiprolol in systemic hypertension

The safety and efficacy of orally administered celiprolol, a new beta 1-selective adrenergic blocking drug with peripheral beta 2-agonist properties, were assessed in 91 patients with mild to moderate systemic hypertension (supine diastolic blood pressure [BP] 95 to 114 mm Hg without medication) using a placebo-controlled, double-blind, randomized, titration-to-effect study design. All patients received placebo for 4 weeks and were then randomized to receive placebo (n = 46) or once-daily celiprolol (n = 45), which was titrated every 2 weeks (200, 400, 600 mg/day) over a 6-week period to achieve a reduction in supine diastolic BP to less than or equal to 90 mm Hg. Plasma lipids and lipoproteins were also assessed at baseline, during placebo and after randomization to active therapy in a subgroup of patients. Compared with placebo, celiprolol reduced supine and standing BP (reduction of supine BP -0.4/-2.1 mm Hg with placebo, -5.7/-6.4 with celiprolol, p less than 0.05; reduction of standing BP -1.7/-1.0 with placebo, -7.2/-4.9 with celiprolol, p less than 0.05). Supine heart rate was reduced by 6.8 beats/min with celiprolol compared with 2.0 beats/min with placebo (p less than 0.05). No differences were seen when the effects of placebo and celiprolol on plasma lipoproteins were compared. Celiprolol is a safe, effective and well tolerated once-daily antihypertensive drug and has no detrimental effects on plasma lipids.