Visual cycle modulators versus placebo or observation for the prevention and treatment of geographic atrophy due to age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is a highly prevalent condition in an ever-increasing elderly population. Although insidious in the early stages, advanced AMD (neovascular and atrophic forms) can cause significant visual disability and economic burden on health systems worldwide. The most common form, geographic atrophy, has no effective treatment to date, whereas neovascular AMD can be treated with intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections. Geographic atrophy has a slow disease progression and patients tend to have preserved central vision until the final stages. This tendency, coupled with the use of modern imaging modalities, provides a large window of opportunity to intervene with validated methods to assess treatment efficacy. As geographic atrophy is an increasingly common condition with no effective intervention, many treatments are under investigation, one of which is visual cycle modulators. These medications have been shown to reduce lipofuscin accumulation in pre-clinical studies that have led to several clinical trials, reviewed herein.

OBJECTIVES

To assess the efficacy and safety of visual cycle modulators for the prevention and treatment of geographic atrophy secondary to AMD.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2020, Issue 1); MEDLINE Ovid; Embase Ovid; Web of Science Core Collection; Scopus; Association for Research in Vision and Ophthalmology (ARVO) website; ClinicalTrials.gov and the WHO ICTRP to 11 January 2020 with no language restrictions. We also searched using the reference lists of reviews and existing studies and the Cited Reference Search function in Web of Science to identify further relevant studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-randomised clinical studies (if available) that compared visual cycle modulators to placebo or no treatment (observation) in people diagnosed with AMD (early, intermediate or geographic atrophy).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias in the included studies and extracted data. Both authors entered data into RevMan 5. We resolved discrepancies through discussion. We graded the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included three RCTs from the USA; one of these had clinical sites in Germany. Two studies compared emixustat to placebo while the other compared fenretinide to placebo. All assigned one study eye per participant and, combined, have a total of 821 participants with a majority white ethnicity (97.6%). All participants were diagnosed with geographic atrophy due to AMD based on validated imaging modalities. All three studies have high risk of attrition bias mainly due to ocular adverse effects of emixustat and fenretinide. We considered only one study to be adequately conducted and reported with high risk of bias in only one domain (attrition bias). We considered the other two studies to be poorly reported and to have high risk of attrition bias and reporting bias. People with geographic atrophy treated with emixustat may not experience a clinically important change in best-corrected visual acuity (BCVA) between baseline and 24 months compared to people treated with placebo (mean difference (MD) 1.9 Early Treatment Diabetic Retinopathy Study (ETDRS) letters, 95% confidence interval (CI) -2.34 to 6.14, low-certainty evidence). Emixustat may also result in little or no difference in loss of 15 ETDRS letters or more of BCVA compared with placebo at 24 months (16.4% versus 18%) (risk ratio (RR) 0.91, 95% CI 0.59 to 1.4, low-certainty evidence). In terms of disease progression, emixustat may result in little or no difference in the annual growth rate of geographic atrophy compared with placebo (mean difference MD 0.09 mm2/year (95% CI -0.26 to 0.44, low-certainty evidence). All three studies reported adverse events of both drugs (emixustat: moderate-certainty evidence; fenretinide: low-certainty evidence). The main adverse events were ocular in nature and associated with the mechanism of action of the drugs. Delayed dark adaptation (emixustat: 54.5%; fenretinide: 39.3%) and chromatopsia (emixustat: 22.6%; fenretinide: 25.2%) were the most common adverse events reported, and were the most prevalent reasons for study dropout in emixustat trials. These effects were dose-dependent and resolved after drug cessation. No specific systemic adverse events were considered related to emixustat; only pruritus and rash were considered to be due to fenretinide. One emixustat study reported six deaths, none deemed related to the drug. None of the included RCTs reported the other pre-specified outcomes, including proportion of participants losing 10 letters or more, and mean change in macular sensitivity. We planned to investigate progression to advanced AMD (geographic atrophy or neovascular AMD) in prevention studies, including participants with early or intermediate AMD, but we identified no such studies. Two of the included studies reported an additional outcome - incidence of choroidal neovascularisation (CNV) - that was not in our published protocol. CNV onset may be reduced in those treated with emixustat but the evidence was uncertain (risk ratio (RR) 0.67, 95% CI 0.27 to 1.65, low-certainty evidence), or fenretinide (RR 0.5, 95% CI 0.26 to 0.98, low-certainty evidence) compared to placebo. A dose-dependent relationship was observed with emixustat.

AUTHORS' CONCLUSIONS

There is limited evidence to support the use of visual cycle modulators (emixustat and fenretinide) for the treatment of established geographic atrophy due to AMD. The possible reduction in the incidence of CNV observed with fenretinide, and to a lesser extent, emixustat, requires formal assessment in focused studies.

The influence of esmolol on right ventricular function in early experimental endotoxic shock

The mechanism by which heart rate (HR) control with esmolol improves hemodynamics during septic shock remains unclear. Improved right ventricular (RV) function, thereby reducing venous congestion, may play a role. We assessed the effect of HR control with esmolol during sepsis on RV function, macrocirculation, microcirculation, end-organ-perfusion, and ventricular-arterial coupling. Sepsis was induced in 10 healthy anesthetized and mechanically ventilated sheep by continuous IV administration of lipopolysaccharide (LPS). Esmolol was infused after successful resuscitation of the septic shock, to reduce HR and stopped 30-min after reaching targeted HR reduction of 30%. Venous and arterial blood gases were sampled and the small intestines' microcirculation was assessed by using a hand-held video microscope (CytoCam-IDF). Arterial and venous pressures, and cardiac output (CO) were recorded continuously. An intraventricular micromanometer was used to assess the RV function. Ventricular-arterial coupling ratio (VACR) was estimated by catheterization-derived single beat estimation. The targeted HR reduction of >30% by esmolol infusion, after controlled resuscitation of the LPS induced septic shock, led to a deteriorated RV-function and macrocirculation, while the microcirculation remained depressed. Esmolol improved VACR by decreasing the RV end-systolic pressure. Stopping esmolol showed the reversibility of these effects on the RV and the macrocirculation. In this animal model of acute severe endotoxic septic shock, early administration of esmolol decreased RV-function resulting in venous congestion and an unimproved poor microcirculation despite improved cardiac mechanical efficiency.

THE SAFETY AND EFFICACY OF AMIODARONE AND CARVEDILOL COMBINATION IN TREATMENT OF PATIENTS WITH SEVERE CARDIAC RHYTHM DISORDERS

Different arrhythmias are cause of sudden death in many patients with heart failure. Amiodarone is usually used for prevent this arrhythmias, but it is not drug of choice for treatment the patients with heart failure. We retrospectively analyzed 142 patients with moderate and severe heart failure and history of myocardial infarction. These patients have received amiodarone, carvedilol or combination of these two medications together with standard therapy. In our retrospective analysis, the combination therapy with Amiodarone and Carvedilol had highly significant decrease arrhythmic death compare with carvedilol and amiodarone groups. This therapy is more effective in recovering of sinus rhythm in patients with atrial fibrillation and for control ventricular arrhythmias. The effects of carvedilol on left ventricular remodeling, systolic function and symptomatic status are not affected adversly by concurrent treatment with amiodarone. Carvedilol is an effective additional therapy for the patients with chronic heart failure already receiving Amiodarone. Carvedilol can be added to Amiodarone in patients with severe ventricular rhythm disorders and increased risk of sudden death without expecting of increase adverse events (than either drug alone) or loss of clinical efficacy.

Rationale and design of the Children's Oncology Group (COG) study ALTE1621: a randomized, placebo-controlled trial to determine if low-dose carvedilol can prevent anthracycline-related left ventricular remodeling in childhood cancer survivors at high risk for developing heart failure

BACKGROUND

Anthracyclines are widely used in the treatment of childhood cancer. One of the well-recognized side-effects of anthracycline therapy is dose-dependent cardiomyopathy that may progress to heart failure (HF) years after completion of cancer-directed therapy. This study will evaluate the efficacy of low-dose beta-blocker (carvedilol) for HF risk reduction in childhood cancer survivors at highest risk for HF. The proposed intervention has the potential to significantly reduce chronic cardiac injury via interruption of neurohormonal systems responsible for left ventricular (LV) remodeling, resulting in improved cardiac function and decreased risk of HF. The intervention is informed by previous studies demonstrating efficacy in pediatric and adult non-oncology populations, yet remains unstudied in the pediatric oncology population.

METHODS/DESIGN

The primary objective of the trial is to determine impact of the intervention on echocardiographic markers of cardiac remodeling and HF risk, including: LV wall thickness/ dimension ratio (LVWT/D; primary endpoint), as well as LV ejection fraction, volume, and blood biomarkers (natriuretic peptides, galectin-3) associated with HF risk. Secondary objectives are to establish safety and tolerability of the 2-year course of carvedilol using: 1) objective measures: hepatic and cardiovascular toxicity, treatment adherence, and 2) subjective measures: participant self-reported outcomes. Two hundred and fifty survivors of childhood cancer (diagnosed <21 years of age), and previously treated with high-dose (≥300 mg/m2) anthracyclines will be enrolled in a randomized, double-blind, placebo controlled trial. After baseline assessments, participants will be randomized in a 1:1 ratio to low-dose carvedilol (maximum dose: 12.5 mg/day) or placebo. Carvedilol or placebo is up-titrated (starting dose: 3.125 mg/day) according to tolerability.

DISCUSSION

When completed, this study will provide much-needed information regarding a physiologically plausible pharmacological risk-reduction strategy for childhood cancer survivors at high risk for developing anthracycline-related HF.

TRIAL REGISTRATION

ClinicalTrials.gov; NCT02717507.

[Risk of renal dysfunction in an elderly patient with chronic heart failure]

The treatment of elderly multimorbid patients according to clinical guidelines often results in polypharmacy. An individual risk assessment is required to consider the possibility of deprescribing especially potentially inappropriate medication in the elderly. This exemplary case report describes a medication review of a patient with multiple chronic cardiovascular diseases taking into account the impact on renal function.

Conversion of Atrial Fibrillation to Sinus Rhythm During Treatment With Intravenous Esmolol or Diltiazem: A Prospective, Randomized Comparison

Prior studies have suggested that intravenous diltiazem reduces the probability of spontaneous conversion of atrial fibrillation (AF) to sinus rhythm in the electrophysiology laboratory and in patients with postoperative AF. Whether diltiazem exerts the same effect in patients presenting to the emergency department (ED) with spontaneous AF is unclear. Fifty patients presenting to the ED with new-onset or paroxysmal AF and a rapid ventricular rate (>100 beats per minute) were randomly assigned to receive intravenous diltiazem or esmolol during the first 24 hours of presentation. Conversion to sinus rhythm occurred in 10 patients (42%) in the diltiazem group compared with 10 patients (39%) in the esmolol group ( P = 1.0). Diltiazem does not decrease the likelihood of spontaneous conversion of AF to sinus rhythm in the ED setting.

Long-Acting Beta Agonists Enhance Allergic Airway Disease

Asthma is one of the most common of medical illnesses and is treated in part by drugs that activate the beta-2-adrenoceptor (β₂-AR) to dilate obstructed airways. Such drugs include long acting beta agonists (LABAs) that are paradoxically linked to excess asthma-related mortality. Here we show that LABAs such as salmeterol and structurally related β₂-AR drugs such as formoterol and carvedilol, but not short-acting agonists (SABAs) such as albuterol, promote exaggerated asthma-like allergic airway disease and enhanced airway constriction in mice. We demonstrate that salmeterol aberrantly promotes activation of the allergic disease-related transcription factor signal transducer and activator of transcription 6 (STAT6) in multiple mouse and human cells. A novel inhibitor of STAT6, PM-242H, inhibited initiation of allergic disease induced by airway fungal challenge, reversed established allergic airway disease in mice, and blocked salmeterol-dependent enhanced allergic airway disease. Thus, structurally related β₂-AR ligands aberrantly activate STAT6 and promote allergic airway disease. This untoward pharmacological property likely explains adverse outcomes observed with LABAs, which may be overcome by agents that antagonize STAT6.

Carvedilol vs. esophageal variceal band ligation in the primary prophylaxis of variceal hemorrhage: a multicentre randomized controlled trial

BACKGROUND & AIMS

Esophageal variceal bleed is a major problem in patients with cirrhosis. Endoscopic variceal ligation (EVL) has been shown to be equal to or better than propranolol in preventing first bleed. Carvedilol is a non-selective β blocker with alpha-1 adrenergic blocker activity. Hemodynamic studies have shown carvedilol to be more effective than propranolol at reducing portal pressure. We compared efficacy of carvedilol with EVL for primary prophylaxis of esophageal variceal bleed.

METHODS

Cirrhotic patients with esophageal varices were randomized to carvedilol 12.5mg daily or EVL at three university hospitals of Pakistan. End points were esophageal variceal bleeding, death or liver transplant.

RESULTS

Two hundred and nine patients were evaluated. Eighty two and eighty six patients were randomized in carvedilol and EVL arms respectively. Mean age was 48 ± 12.2 years; 122 (72.7%) were males; 89.9% had viral cirrhosis; mean Child-Pugh score was 7.3 ± 1.6 and mean follow up was 13.3 ± 12.1 months (range 1-50 months). Both EVL and carvedilol groups had comparable variceal bleeding rates (8.5% vs. 6.9%), bleed related mortality (4.6% vs. 4.9%) and overall mortality (12.8% vs. 19.5%) respectively. Adverse events in carvedilol group were hypotension (n=2), requiring cessation of therapy, while transient nausea (n=18) and dyspnea (n=30) resolved spontaneously. In the EVL arm, post banding ulcer bleed (n=1) and chest pain (n=17), were termed as serious adverse events while transient dysphagia (n=58) resolved without treatment.

CONCLUSIONS

Although our study is underpowered, the findings suggest that carvedilol is probably not superior to EVL in preventing first variceal bleed in patients with viral cirrhosis.

Electrocardiographic response to intravenous and intraarterial injection of iosimenol (a new, iodinated, non-ionic, iso-osmolar contrast medium)

Serious arrhythmias, sometimes related to the injection of iodinated contrast media, are known complications of cardiac angiography. A new, iodine-based, non-ionic, iso-osmolar x-ray contrast media is in development for use in these procedures. This contrast medium, iosimenol, has a lower viscosity, higher electrolyte content, and higher iodine concentration than other available iso-osmolar contrast media. The present study is a retrospective re-read and centralized analysis of the electrocardiographic response to intravenous and non-cardiac intraarterial injections of iosimenol, placebo, or iodixanol (Visipaque; GE Healthcare, Inc) in a total of 167 healthy subjects and patients enrolled in early clinical trials. No clinically relevant changes in heart rate and rhythm, morphology, atrioventricular conduction, or ventricular repolarization were noted after injection of any of the test articles in these studies. These results, despite the limited number of patients in these trials, suggest that iosimenol can be used safely in larger populations.

Effect of heart rate control with esmolol on hemodynamic and clinical outcomes in patients with septic shock: a randomized clinical trial

IMPORTANCE

β-Blocker therapy may control heart rate and attenuate the deleterious effects of β-adrenergic receptor stimulation in septic shock. However, β-Blockers are not traditionally used for this condition and may worsen cardiovascular decompensation related through negative inotropic and hypotensive effects.

OBJECTIVE

To investigate the effect of the short-acting β-blocker esmolol in patients with severe septic shock.

DESIGN, SETTING, AND PATIENTS

Open-label, randomized phase 2 study, conducted in a university hospital intensive care unit (ICU) between November 2010 and July 2012, involving patients in septic shock with a heart rate of 95/min or higher requiring high-dose norepinephrine to maintain a mean arterial pressure of 65 mm Hg or higher.

INTERVENTIONS

We randomly assigned 77 patients to receive a continuous infusion of esmolol titrated to maintain heart rate between 80/min and 94/min for their ICU stay and 77 patients to standard treatment.

MAIN OUTCOMES AND MEASURES

Our primary outcome was a reduction in heart rate below the predefined threshold of 95/min and to maintain heart rate between 80/min and 94/min by esmolol treatment over a 96-hour period. Secondary outcomes included hemodynamic and organ function measures; norepinephrine dosages at 24, 48, 72, and 96 hours; and adverse events and mortality occurring within 28 days after randomization.

RESULTS

Targeted heart rates were achieved in all patients in the esmolol group compared with those in the control group. The median AUC for heart rate during the first 96 hours was -28/min (IQR, -37 to -21) for the esmolol group vs -6/min (95% CI, -14 to 0) for the control group with a mean reduction of 18/min (P < .001). For stroke volume index, the median AUC for esmolol was 4 mL/m2 (IQR, -1 to 10) vs 1 mL/m2 for the control group (IQR, -3 to 5; P = .02), whereas the left ventricular stroke work index for esmolol was 3 mL/m2 (IQR, 0 to 8) vs 1 mL/m2 for the control group (IQR, -2 to 5; P = .03). For arterial lactatemia, median AUC for esmolol was -0.1 mmol/L (IQR, -0.6 to 0.2) vs 0.1 mmol/L for the control group (IQR, -0.3 for 0.6; P = .007); for norepinephrine, -0.11 μg/kg/min (IQR, -0.46 to 0.02) for the esmolol group vs -0.01 μg/kg/min (IQR, -0.2 to 0.44) for the control group (P = .003). Fluid requirements were reduced in the esmolol group: median AUC was 3975 mL/24 h (IQR, 3663 to 4200) vs 4425 mL/24 h(IQR, 4038 to 4775) for the control group (P < .001). We found no clinically relevant differences between groups in other cardiopulmonary variables nor in rescue therapy requirements. Twenty-eight day mortality was 49.4% in the esmolol group vs 80.5% in the control group (adjusted hazard ratio, 0.39; 95% CI, 0.26 to 0.59; P < .001).

CONCLUSIONS AND RELEVANCE

For patients in septic shock, open-label use of esmolol vs standard care was associated with reductions in heart rates to achieve target levels, without increased adverse events. The observed improvement in mortality and other secondary clinical outcomes warrants further investigation.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01231698.

[Effect of monotherapy with nebivolol, bisoprolol, carvedilol on the state of vegetative nervous system and sexual function in men with arterial hypertension]

Aim of the study was to assess effect of monotherapy with nebivolol, bisoprolol, carvedilol for 2 months on sexual function in men with arterial hypertension (AH). Men with 1-2 degree of AH (n=75, age 35-55 years, mean age 48+/-3,5 years) received monotherapy with these drugs for 2 months. Registration of parameters of heart rate variability (HRV), Dopplerography of penile arteries, and the Vasilchenko questionnaire were implemented at the end of 4 months of placebo period and after 2 months of therapy with a study drug. Therapy with bisoprolol, carvedilol, and nebivolol was associated with significant elevation of parasympathetic part of vegetative nervous system tone, improvement of systolic blood flow in cavernous and dorsal arteries. Analysis of data obtained by Vasilchenko questionnaire demonstrated improvement of psychic and erectile components of sexual function. Thus bisoprolol, carvedilol, and nebivolol did not worsen sexual function of men with AH, improved spectral parameters of HRV and vascular blood flow in arteries of cavernous bodies.

Pharmacological interventions for treating heart failure in patients with chagas cardiomyopathy

BACKGROUND

Chagas disease-related cardiomyopathy is a major cause of morbidity and mortality in Latin America. Despite the substantial burden to the healthcare system, there is uncertainty regarding the efficacy and safety of pharmacological interventions for treating heart failure in patients with Chagas disease.

OBJECTIVES

To assess the benefits and harms of current pharmacological interventions for treating heart failure in patients with Chagas cardiomyopathy.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library) Issue 1, 2011, MEDLINE (Ovid), EMBASE (Ovid), LILACS and ISI Web of Science to April 2011. We checked the reference lists of included papers. No language restrictions were applied.

SELECTION CRITERIA

We included randomized clinical trials assessing the effects of pharmacological interventions for treating heart failure in adult patients (≥18 years) with symptomatic heart failure (New York Heart Association class II to IV), irrespective of the left ventricular ejection fraction stage, reduced or preserved, with Chagas cardiomyopathy. No limits were applied with respect to the follow-up duration. Primary outcomes were all-cause mortality, cardiovascular mortality at 30 days, time to heart decompensation and disease-free period (at 30, 60 and 90 days), and adverse events.

DATA COLLECTION AND ANALYSIS

Two authors independently performed study selection, risk of bias assessment and data extraction. We estimated relative risks (RR) and the respective 95% confidence intervals (CIs) for dichotomous outcomes. We measured statistical heterogeneity using the I(2) statistic. We used a fixed-effect model to synthesize the findings. We contacted authors for additional data.

MAIN RESULTS

We included two randomized clinical trials involving 69 participants. Both trials compared carvedilol against placebo, and had a high risk of bias. Carvedilol compared with placebo did not significantly affect all-cause mortality (2/34 (5.88%) versus 3/35 (5.87%); pooled RR 0.69, 95% CI 0.12 to 3.88, I(2) = 0%). None of the trials reported on cardiovascular mortality, time to heart decompensation or disease-free period. Evidence on the adverse effects of carvedilol is inconclusive.

AUTHORS' CONCLUSIONS

This Cochrane review has found a lack of evidence on the effects of carvedilol for treating heart failure in patients with Chagas disease. The two included trials were underpowered and had a high risk of bias. There are no conclusive data to support the use of carvedilol for treating Chagas cardiomyopathy. Unless randomized clinical trials provide evidence of a treatment effect, and the trade off between potential benefits and harms is established, policy-makers, clinicians, and academics should be cautious when recommending and administering carvedilol for treating heart failure in patients with Chagas disease. The efficacy and safety of other pharmacological interventions for treating heart failure in patients with Chagas disease is unknown.

Feasibility of conjunctival hemodynamic measurements in rabbits: reproducibility, validity, and response to acute hypotension

OBJECTIVE

To evaluate the feasibility of conjunctival hemodynamic measurements based on assessment of reproducibility, validity, and response to acute hypotension.

METHODS

Image sequences of the conjunctival microvasculature of rabbits were captured using a slit lamp biomicroscope under a steady-state condition, after topical administration of phenylephrine, and after intravenous administration of esmolol. Venous hemodynamic parameters (diameter, blood velocity, blood flow, and wall shear stress) were derived.

RESULTS

Conjunctival venous diameters ranged from 9 to 34 μm and blood velocities ranged from 0.08 to 0.95 mm/s. Coefficients of variation of venous diameter and blood velocity measurements were, on average, 6% and 14%, respectively. Automated and manual measurements of venous diameter and velocity were highly correlated (R = 0.97; p < 0.001; n = 16). With phenylephrine administration, diameter and velocity were reduced by 21% and 69%, respectively. Following esmolol administration, blood pressure was reduced with a concomitant decrease in velocity, followed by recovery to baseline. Venous blood velocity, flow, and WSS were correlated with blood pressure (R ≥ 0.52; p ≤ 0.01).

CONCLUSIONS

The feasibility of quantifying alterations in microvascular hemodynamics in the bulbar conjunctiva was established. The method is of potential value in evaluating microcirculatory hemodynamics related to cardiovascular function.

Persistence with nebivolol in the treatment of hypertension: a retrospective claims analysis

OBJECTIVE

Examine drug persistence by evaluating the hazard of discontinuation and of switching to different antihypertensive drugs in patients initiating treatment with a recently approved β-blocker, nebivolol, versus other β-blockers.

METHODS

This retrospective analysis included all patients diagnosed with hypertension in the MarketScan Database (January 2007 - December 2008) with at least two medical claims and no prior β-blocker prescriptions within 6 months of the initial prescription date. Multivariate Cox proportional hazard models (adjusted for baseline differences in demographics, previous use of other antihypertensive medications, initial doses and supply of medication, and number of distinct prescriptions at baseline) were used to assess the hazard of discontinuation, defined as the first prescription gap of ≥30 days, and to assess the hazard of switching to another antihypertensive drug, defined as a prescription fill for another antihypertensive drug within 15 days before and 30 days after discontinuation of the initial β-blocker.

RESULTS

Of the 173,200 patients included in the study population, the adjusted hazard of discontinuation for nebivolol-initiated patients was 8-20% lower than that of patients who initiated treatment with atenolol (hazard ratio [HR] 0.82, p < 0.001), metoprolol (HR 0.91, p < 0.001), carvedilol (HR 0.92, p < 0.001), or other β-blockers (HR 0.80, p < 0.001). The adjusted hazard of nebivolol-treated patients switching to a different antihypertensive medication was 12-22% lower than that of the other four β-blocker cohorts (atenolol: HR 0.80, p < 0.001; metoprolol: HR 0.86, p < 0.001; carvedilol: HR 0.88, p < 0.001; other β-blockers: HR 0.78, p < 0.001). Sensitivity analyses defined discontinuation as prescription gaps of ≥45 days and ≥60 days and showed a lower hazard of discontinuation among patients initiating nebivolol than among patients initiating all other drug cohorts (p < 0.001).

LIMITATIONS

Comparisons of non-randomized treatment groups may be confounded by unobserved differences in patients' baseline characteristics.

CONCLUSIONS

Initiation with nebivolol was associated with greater persistence than initiation with atenolol, carvedilol, metoprolol, or other β-blockers.

Use of gabapentin, esmolol or their combination to attenuate haemodynamic response to laryngoscopy and intubation

BACKGROUND

Laryngoscopy and intubation increases blood pressure and heart rate.

OBJECTIVE

The study aims to investigate the effect and safety of gabapentin, esmolol or their combination on the haemodynamic response to laryngoscopy and intubation.

METHODS

A total of 72 patients undergoing elective surgery were randomly allocated to one of the four groups. First study drug was administered orally as gabapentin 1200mg or placebo. Second study drug was administered intravenously as esmolol 1.5mg/ kg or normal saline. Heart rate, rate pressure product, systolic blood pressure and mean arterial pressure were recorded at baseline and at zero, one, three and five minutes after tracheal intubation.

RESULTS

Baseline values were compared with the values at various time intervals within the same group. In group PE (placebo, esmolol), there was significant decrease in heart rate and rate pressure product at five minutes. In group GN (gabapentin, normal saline), there was significant decrease in systolic blood pressure and mean arterial pressure at five minutes. In group GE (gabapentin, esmolol), there was significant decrease in heart rate at zero, three and five minutes. Systolic blood pressure, mean arterial pressure and rate pressure product was significantly lower at three and five minutes. In group PN (placebo, normal saline), there was significant increase in heart rate at zero, one, three and five minutes; systolic blood pressure at zero and one minutes; mean arterial pressure at zero and one minutes and rate pressure product at zero, one and three minutes. In group GN (gabapentin, normal saline), there was significant increase in heart rate at zero, one and three minutes and rate pressure product at zero, one and three minutes. In group PE (placebo, esmolol), there was significant increase in systolic blood pressure at zero and one minutes and mean arterial pressure at zero and one minutes. However, in group GE (gabapentin, esmolol) none of the variables showed statistically significant increase at any time. Inter-group comparison was made for each time point. At zero minute, there was significant difference in heart rate between groups PN and GE, GN and PE and GN and GE Significant difference was also noted in rate pressure product between PN and GE at zero minute. At one minute there was difference in heart rate between PN and PE, PN and GE, GN and PE and between GN and GE. Significant difference was observed in rate pressure product between PN and PE amd between PN and GE at one minute. No significant side effects of the study drugs were observed.

CONCLUSIONS

Combination of gabapentin and esmolol in this study design is safe and better attenuates both the pressor and tachycardic response to laryngoscopy and intubation, than either agent alone.

Risk of new-onset diabetes mellitus associated with beta-blocker treatment for hypertension

BACKGROUND

This study investigated the risk of new-onset diabetes (NOD) among hypertensive patients initiating carvedilol therapy vs other beta-blocker (BB) therapy in a clinical practice setting.

METHODS

Patients aged ≥18 years with ≥1 pharmacy claim for a BB of interest (carvedilol immediate-release [IR]/controlled-release [CR], atenolol, metoprolol succinate, or metoprolol tartrate) were identified in the IMS LifeLink Health Plan Claims Database. Index date was the first chronologically occurring prescription for any BB during the enrollment period (July 1, 2000-December 31, 2007). Patients had to be continuously eligible to receive healthcare services 6 months prior to and a minimum of 3 months after index date and have ≥1 diagnostic code for hypertension (ICD-9-CM: 401.xx-405.xx) during this time frame. Patients were excluded for having a diagnosis of diabetes mellitus (ICD-9-CM: 250.xx) and/or prescription for antidiabetic therapy in the 6 months prior to and/or 3 months after index date. Eligible patients were propensity-score matched in a 1:3 ratio (carvedilol : other BBs). Mean duration of follow-up was 12.8 and 14.8 months for the carvedilol group and other BB group, respectively. Primary outcome of interest was presence and timing of NOD.

RESULTS

Among 3084 patients in the carvedilol group and 9252 in the other BB group, mean age was 56 years, with 54% male. NOD rate was 3.16 per 100 person-years for carvedilol patients vs 3.36 for patients in the other BB group (NS). Risk of NOD was similar between groups (HR 0.971, 95% CI: 0.78, 1.21; P = 0.792).

CONCLUSIONS

Findings suggest the risk of NOD among hypertensive patients is similar between carvedilol and other BB agents (i.e., atenolol, metoprolol succinate, or metoprolol tartrate).

LIMITATIONS

The use of administrative claims data and relatively short follow-up period may limit the generalizability of results.

In vitro and in vivo evaluation of the effects of duloxetine on P-gp function

OBJECTIVE

To evaluate the effect of duloxetine (DLX) on the P-glycoprotein (P-gp) function in vitro and in vivo.

METHOD

In vitro experiment was conducted using the Caco-2 cell, a human colon cancer cell line that naturally expresses the P-gp and P-gp function was evaluated by monitoring whether DLX affect the accumulation of Rhd123. In vivo study was conducted by quantitating the effect of orally administered DLX on the bioavailability of talinolol.

RESULTS

In the in vitro study, incubation of Caco-2 cell with DLX caused a concentration-dependent increase in the accumulation of Rhd123. In the in vivo study, co-administration of DLX increased the bioavailability of talinolol. The ratio (90% confidence intervals) of AUC(0-60), AUC(0-∞), and C(max) (talinolol alone versus talinolol plus DLX) were 0.87(0.77-1.06), 0.85(0.74-1.01), 0.87 (0.68-1.12).

CONCLUSION

Our results suggest that DLX could inhibit the function of P-gp in vitro and in vivo, and caution should be exercised when DLX is to be co-administered with drugs that are P-gp substrate.

[Comparative eficacy of antihypertensive therapy in patients with arterial hypertension and various sensitivity to salt]

In 102 patients with high risk (52 patients with history of myocardial infarction, 50 patients with history of cerebral stroke within previous 6-48 months) arterial hypertension (AH) we studied clinical efficacy on angiotensin converting enzyme inhibitor (ACEI) lisinopril, calcium antagonist felodipine, and nonselective - -blocker carvedilol in dependence on salt sensitivity of AH. Efficacy of treatment was assessed with the help of office pressure measurement and 24 hour arterial pressure monitoring before and after 12 weeks of therapy. Patients who showed 10 or more mm Hg lowering of AP at transition from high salt (15 g/day) to low salt ( 3 g/day) diet were considered salt sensitive. On the basis of obtained results optimal for the treatment of AH in salt resistant patients are ACEI while in the treatment of salt sensitive patients it is expedient to administer calcium antagonists. The use of -adrenoblockers is equally effective in AH with various salt sensitivity.

[Beta-adrenoblockers for the correction of arterial hypertension in postmenopausal women]

The use of beta-blockers is an important component of therapy of cardiovascular pathology (e.g. coronary heart disease, arterial hypertension) in menopausal women. Comparative data on the efficiency of lokren and carvedilol for the correction of grade 2 AH are presented.

A new water-soluble, selective beta-blocker with intrinsic sympathomimetic activity (ICI 141.292) in angina pectoris

In a placebo-controlled, randomized double-blind study the effect of ICI 141.292 (beta 1-selective beta-blocker with intrinsic sympathomimetic activity = ISA) was studied in 11 patients with severe angina pectoris. The doses used were 100, 200 and 300 mg once daily. The 24-hour heart rate was significantly reduced by all regimens, and the Holter-monitoring pattern indicated the presence of ISA-effect at least 20 hours after the 300-mg dose. Maximal heart rate and blood pressure were significantly reduced and exercise duration increased during a symptom-limited bicycle exercise test on 200 and 300 mg, but not on 100 mg daily. Resting heart rate and blood pressure were uninfluenced on all regimens. ICI 141.292 is an effective agent in patients with severe angina pectoris. The response pattern suggests the presence of clinically relevant ISA.

Timolol eyedrop-induced severe bronchospasm

A patient with glaucoma simplex and chronic pulmonary obstruction was treated with the non-selective beta-adrenergic blocking agent timolol in ophthalmic solution of 0.25% for 11/2 years, when he had daily asthma attacks. In a provocation test, forced expiratory volume in the first second was reduced by 56% and bradycardia was induced after application of two drops of timolol eyedrops 0.25%. The severe systemic side-effects of timolol, when used as eyedrops, are related to the liver bypass and perhaps to the fast absorption from the cornea. It is suggested that when timolol ophthalmic solution is given for the first time to glaucoma patients with chronic obstructive pulmonary disease, they should be observed for one hour with special reference to difficulty in breathing.

Peripheral vasospasm during beta-receptor blockade - a comparison between metoprolol and pindolol

Ten men reported vasospastic symptoms in their hands during metoprolol treatment. They had no signs of occlusive arterial disease. The temperature reaction to local cooling was measured and no improvement was found after changing to pindolol. Vasospastic symptoms during beta-receptor blockade may arise in predisposed individuals irrespective of the type of beta-receptor antagonist used.

Carvedilol therapy in pediatric patients with dilated cardiomyopathy

Carvedilol reduces mortality and hospitalization in adults with congestive heart failure. Limited information is available about its use in children. The objective of this study was to determine the dosing, efficacy and side effects of carvedilol for the management of dilated cardiomyopathy in children. Sixteen children with idiopathic dilated cardiomyopathy, aged 7 months to 138 months and with an ejection fraction less than 40%, were treated with carvedilol. The average initial dose was 0.1 mg/kg/day and it was uptitrated to 0.4 mg/kg/day. After six months on carvedilol, there were improvements in clinical scoring system from an average of 2.94 to 2.50 (p<0.05), in mean fractional shortening from 17.2 +/- 6.1% to 22.7 +/- 5.1% (p<0.05), and in ejection fraction from 35.2 +/- 6.8% to 43.1 +/- 11.2% (p<0.05). No side effect was observed during the study period. Two patients died due to serious infection. Carvedilol in addition to standard therapy for dilated cardiomyopathy in children improves cardiac function and symptoms. It is well tolerated, with minimal adverse effects, but close monitoring is necessary.

Multiple drug interactions in a renal transplant patient leading to simvastatin-induced rhabdomyolysis: a case report

Rhabdomyolysis, a syndrome characterized by muscle necrosis with release of toxic intracellular muscle constituents, can be a potentially fatal side effect of medical therapy. Here I report a patient with a 12-year history of simvastatin use who presented with rhabdomyolysis. He had a renal transplant and has been on a stable dose of cyclosporine for the past year. Recent medication changes were the addition of ranolazine, carvedilol, and diltiazem about two months prior to the episode of rhabdomyolysis. Discontinuation of the ranolazine, diltiazem, and simvastatin resulted in prompt resolution of the episode. It is suggested that these medications, acting in concert with cyclosporine, altered the metabolism of simvastatin, causing the episode of rhabdomyolysis. Clinicians should be alert to the possibility of multiple drug interactions causing rhabdomyolysis.

[Are mortality or morbidity risks appropriate endpoints for interventional studies in primary or secondary prevention with shared decision-making?]

The choice of primary and secondary endpoints for the individual studies of a research and development program is a classical biometric problem. Far-reaching decisions have to be made on the basis of incomplete information. Early studies in a program usually have functional or symptom-driven endpoints; the larger subsequent trials will usually focus on quality of life, morbidity or mortality. For program acceleration and cost reduction surrogate parameters are welcome. Unfortunately, there are only a few generally accepted surrogates for morbidity or mortality. At first glance, risk scores seem to be a suitable means for filling this gap. They are easily calculated, comprehensive and thus form a solid base for shared decision-making. However, further reasoning reveals that risk scores do not meet the usual standards for surrogates. What is more, a treatment targeting the reduction of a risk score cannot be considered an evidence-based intervention, which is due to a lack of randomized trials that compare risk score reduction to conventional interventions focussing on isolated risk factors. Thus, risk scores are unsuitable for primary endpoints, whereas they play an important role as comprehensive explanatory variables in study evaluation, i.e., for the description of population characteristics and as potential control variables or effect modifiers.

Effect of arotinolol on left ventricular function in patients with idiopathic dilated cardiomyopathy

OBJECTIVE

To evaluate the efficacy and safety of long-term treatment with arotinolol in patients with idiopathic dilated cardiomyopathy (IDCM).

METHODS

Sixty-three patients with IDCM were evaluated at baseline and after 12-month therapy with arotinolol. The conventional therapy for congestive heart failure was continued throughout the study with arotinolol as the only beta-blocker. Left ventricular function was assessed with the New York Heart Association functional class and two-dimensional echocardiography.

RESULTS

After 12-month arotinolol treatment, there was a significant improvement in left ventricular systolic function. Left ventricular end-systolic dimension significantly decreased from 59.52 +/- 8.83 mm to 50.89 +/- 8.17 mm (P < 0.001). Left ventricular ejection fraction significantly increased from 27.39% +/- 7.94% to 41.13% +/- 9.45% ( P < 0.001). Left ventricular mass index decreased from 150.47 +/- 42.42 g/m2 to 141.58 +/- 34.36 g/m2 (P < 0.01). No adverse events leading to premature discontinuation of study drug occurred.

CONCLUSION

In this preliminary study, 12-month arotinolol treatment has a favorable effect on left ventricular function in patients with IDCM, and it is safe and well tolerated.

Safety and efficacy of carvedilol in very elderly diabetic patients with heart failure

OBJECTIVE

Beta-blockers are often cautiously prescribed to older heart failure diabetics because of the paucity of published data and their perceived unfavourable effects on glucose metabolism, in spite of the evidence of their effectiveness and safety in middle-aged diabetic patients. The aim of this study was to compare the safety, tolerability and efficacy of long-term administration of carvedilol in a group of elderly patients with chronic heart failure, with and without concomitant diabetes.

METHODS

Two hundred and fifty-two patients aged > or =70 years with heart failure and left ventricular ejection fraction < or =40% were followed in specialised heart failure clinics. Diabetes was present in 29.7%. Carvedilol was associated with conventional optimised treatment in 64% of diabetics and 65% of non-diabetics (P = NS).

RESULTS

At baseline, diabetics presented with a longer duration of symptoms, higher Charlson comorbidity index, more frequent renal dysfunction and smaller left ventricular volumes than non-diabetics. New York Heart Association functional class and ejection fraction were similar in the two groups. At 1-year follow-up, tolerability (93.7 vs. 92.2%) and mean daily dose (24 +/- 17 vs. 23 +/- 14 mg/day) of carvedilol were similar in diabetics and non-diabetics. No worsening of fasting glucose, glycosylated haemoglobin and creatinine levels as well as the incidence of deaths and hospitalisations was observed in diabetics treated with carvedilol. Similar improvements in New York Heart Association class and mitral regurgitation severity were observed in diabetic and non-diabetic patients taking carvedilol. Ejection fraction showed a significant improvement, more pronounced in non-diabetics than in diabetics (+10 vs. +7 points; improvement of at least 10 points: 15 vs. 36%, P = 0.03).

CONCLUSIONS

Similarly to younger ones, also in older patients, diabetes does not negatively influence the safety, tolerability and efficacy of carvedilol. However, diabetes remains a strong prognostic factor limiting the reversibility of left ventricular systolic dysfunction and the effect of treatment on subsequent outcome.

Iosimenol, a new non-ionic dimeric contrast medium, does not induce immunoreactivity in the popliteal lymph node assay

Animal studies in mice were conducted to determine the potential immunoreactivity of the new non-ionic dimeric contrast medium (CM) iosimenol using the PLNA and flow cytometric analyses. Comparative studies were performed with iodixanol. The known immune-reactive substance strepozotocin (STZ) and vehicle injections served as positive and negative controls, respectively. Our experiments did not show any immunological effect of iosimenol, concluding that the new CM iosimenol may be beneficial for use in high-risk patients.

Tolerability of beta-blockers in outpatients with refractory heart failure who were receiving continuous milrinone

STUDY OBJECTIVE

To investigate the dosing, tolerability, and outcomes associated with the use of concomitant beta-blockers and inotropic therapy in patients with refractory heart failure during the first 6 months of their therapy.

DESIGN

Retrospective review.

SETTING

University-based, tertiary care heart failure and transplant center.

PATIENTS

Sixteen inotrope-dependent outpatients with end-stage refractory heart failure who were receiving continuous intravenous milrinone. Of these patients, 12 also received an oral beta-blocker; the remaining four patients who did not receive beta-blockers served as the comparator group.

MEASUREMENTS AND MAIN RESULTS

For each patient, the initial and final study drug doses of continuous intravenous milrinone and oral beta-blocker treatment, when applicable, were recorded over the 6-month period. Mean heart rate, blood pressure, ejection fraction, and oxygen consumption were measured, and 95% confidence intervals were calculated. Serum sodium and creatinine concentrations, as well as the creatinine clearance, were measured. In the 12 patients who received concomitant milrinone and beta-blockers, the mean baseline ejection fraction was approximately 18%, and they received milrinone for 18.6 weeks. Seven patients received carvedilol for 16.1 weeks, and five received metoprolol tartrate for 17.6 weeks. Dosages of the beta-blockers were titrated. Final daily doses were carvedilol 42.8 mg (95% confidence interval 20.3-65.4) and metoprolol 42.5 mg (95% confidence interval 28.0-57.2). Patients continued to receive other standard oral drug therapy for heart failure. One patient discontinued metoprolol and one discontinued carvedilol because of hypotension and/or worsening heart failure. Cardiac adverse events in the concomitant milrinone plus beta-blocker group were heart failure requiring hospitalization in 10 patients and ventricular arrhythmias in one.

CONCLUSION

Inotrope-dependent patients with refractory end-stage heart failure tolerated continuous intravenous milrinone plus beta-blockers in addition to diuretics and vasodilators for the 6-month observation period. Beta-blocker dosages were titrated, and three patients achieved the target beta-blocker dosage established for stage A-C heart failure. Additional studies are needed to determine the optimal selection and dosing of drug combinations in this population.

Comparison of Nicardipine Versus Esmolol in Attenuating the Hemodynamic Responses to Anesthesia Emergence and Extubation

OBJECTIVE

The purpose of this study was to compare the effectiveness of intravenous (IV) nicardipine versus esmolol in controlling heart rate (HR) and blood pressure (BP) responses to emergence and extubation.

DESIGN

Prospective, randomized, double blind.

SETTING

University hospital, single institution.

PARTICIPANTS

Twenty-two American Society of Anesthesiologists physical class 1 to 3 adult inpatients scheduled for general anesthesia.

INTERVENTIONS

General endotracheal anesthesia with oxygen/isoflurane and muscle relaxation. At end of surgery, with at least 2 twitches by nerve stimulator and end-tidal isoflurane <0.4%, muscle relaxant reversal was accomplished with neostigmine and glycopyrrolate. Two minutes postreversal, the IV study drug nicardipine, 0.03 mg/kg, or esmolol, 1.5 mg/kg, was administered. HR and BP were measured every minute up to 10 minutes and at minute 15 postreversal.

MEASUREMENTS AND MAIN RESULTS

There were no significant differences between groups in age, weight, gender, American Society of Anesthesiologists physical class or preoperative hemodynamics (HR, BP, mean arterial pressure [MAP]). Compared with nicardipine, 0.03 mg/kg IV, esmolol, 1.5 mg/kg IV, significantly (p < 0.05) attenuated HR more than nicardipine for the 15-minute time period poststudy drug. Compared with esmolol, nicardipine was significantly (p < 0.05) more effective in controlling MAP and systolic BP for the 1- to 3-minute and diastolic BP for the 1- to 2-minute time periods poststudy drug. There were no episodes of hypotension or adverse events.

CONCLUSIONS

Although esmolol, 1.5 mg/kg, IV was more effective than nicardipine, 0.03 mg/kg, IV for attenuating the HR response to extubation, nicardipine was more effective in controlling the BP response.

The influence of beta-blockers on delayed memory function in people with cognitive impairment

Adrenergic signaling is important for the retrieval of intermediate-term contextual and spatial memories. The role of norepinephrine in retrieval requires signaling through beta1-adrenergic receptors in the hippocampus. Environmental cues activate the locus ceruleus, the main adrenergic nucleus of the brain, when an environmental stimulus is memorable. This leads to norepinephrine activation in the hippocampus, which is important for retrieving memories. Although beta-blockers do not impair cognition in normal subjects, this article explores the possibility that central nervous system (CNS)-active beta-blockers could affect delayed memory in patients with cognitive impairment. The authors investigated the influence of beta-blockers on delayed memory function in cognitively impaired patients. There was a trend for worse delayed memory retrieval in patients who were on CNS-active beta-blockers. These data support the notion that common medications used in cognitively impaired elderly patients can worsen cognition and that careful selection of medications may help to maximize retrieval of newly formed memories.

Phase III long-term study and comparative clinical study of nipradilol ophthalmic solution in patients with primary open-angle glaucoma and ocular hypertension

Nipradilol (CAS 81486-22-8) is a non-selective beta-blocker with alpha-1 blocking and nitroglycerin-like vasodilating activities. In the present communication, the long-term efficacy and safety of nipradilol were investigated and the efficacy, safety and utility of topical nipradilol and timolol (CAS 91524-16-2) were compared in patients with primary open-angle glaucoma or ocular hypertension. In the long-term study, nipradilol for 1 year (52 weeks) was performed by registration method. 67 out of 68 patients were subjected to analysis and 57 patients (83.8 %) completed 52-week instillation. 0.25 % nipradilol was applied twice daily to patients. As a result, intraocular pressure (IOP) decreased significantly by 4.0 mmHg to 4.8 mmHg compared with the baseline without tachyphylaxis. The incidence of adverse events was 12.5 % at 52 weeks by analysis with Kaplan-Meier life-table method. It showed no significant trend of increase after 3 months. In the multi-centered double-masked comparative randomized study, 0.25 % nipradilol was assigned to 96 patients and 0.5 % timolol to 100 patients. Each patient was instilled nipradilol or timolol twice daily for 8 weeks. IOP significantly decreased by 4.2 mmHg and by 4.7 mmHg at 8 weeks and the incidence of adverse events was 10.5 % and 12.1 % in the nipradilol and timolol group, respectively. No significant between-group difference in IOP reduction or incidence of adverse events was seen. Topical nipradilol showed long-term ocular hypotensive effects and clinical safety in a 52-week study, and its efficacy and safety equivalent to timolol was confirmed in a 8-week comparative study.

Effects of metoprolol and carvedilol on pre-existing and new onset diabetes in patients with chronic heart failure: data from the Carvedilol Or Metoprolol European Trial (COMET)

BACKGROUND

Beta blocker treatment may worsen glucose metabolism.

OBJECTIVE

To study the development of new onset diabetes in a large cohort of patients with heart failure treated with either metoprolol or carvedilol.

DESIGN

Prospective and retrospective analysis of a controlled clinical trial.

SETTING

Multinational multicentre study.

PATIENTS

3029 patients with chronic heart failure.

INTERVENTIONS

Randomly assigned treatment with carvedilol (n = 1511, target dose 50 mg daily) or metoprolol tartrate (n = 1518, target dose 100 mg daily).

RESULTS

Diabetic events (diabetic coma, peripheral gangrene, diabetic foot, decreased glucose tolerance or hyperglycaemia) and new onset diabetes (clinical diagnosis, repeated high random glucose level or glucose lowering drugs) were assessed in 2298 patients without diabetes at baseline. Diabetic events occurred in 122/1151 (10.6%) patients in the carvedilol group and 149/1147 (13.0%) patients in the metoprolol group (hazard ratio (HR) = 0.78; 95% confidence interval (CI) 0.61 to 0.99; p = 0.039). New onset diabetes was diagnosed in 119/1151 (10.3%) v 145/1147 (12.6%) cases in the carvedilol and metoprolol treatment groups (HR = 0.78, CI 0.61 to 0.997; p = 0.048), respectively. Patients with diabetes at baseline had an increased mortality compared with non-diabetic subjects (45.3% v 33.9%; HR = 1.45, CI 1.28 to 1.65). Both diabetic and non-diabetic subjects at baseline had a similar reduction in mortality with carvedilol compared with metoprolol (RR = 0.85; CI 0.69 to 1.06 and RR = 0.82; CI 0.71 to 0.94, respectively).

CONCLUSION

A high prevalence and incidence of diabetes is found in patients with heart failure over a course of 5 years. New onset diabetes is more likely to occur during treatment with metoprolol than during treatment with carvedilol.

Relationship Between β-Blocker Treatment and the Severity of Central Sleep Apnea in Chronic Heart Failure

BACKGROUND

We sought to examine the relationship between use of beta-blockers and the severity of central sleep apnea (CSA) in patients with chronic heart failure.

METHODS

We performed polysomnography in 45 patients with chronic heart failure (New York Heart Association functional class II/III and left ventricular ejection fraction < 50%) and examined the relationship between use of beta-blockers and the severity of CSA. Central apnea index (CAI) was used as an indicator of CSA.

RESULTS

Patients receiving beta-blockers (ie, carvedilol; n = 27) had lower apnea-hypopnea index (AHI) and CAI than patients not receiving beta-blockers (n = 18) [mean +/- SD, 14 +/- 11 vs 33 +/- 17, p < 0.0001; and 1.9 +/- 3.2 vs 11 +/- 12, p = 0.0004, respectively]. AHI and CAI were negatively correlated with the dose of carvedilol (Spearman rho = - 0.61, p < 0.0001; and Spearman rho = - 0.57, p = 0.0002, respectively). Multiple regression analysis selected no use of beta-blockers as an independent factor of CAI (p = 0.0006). In five patients with CAI > 5 who underwent serial sleep studies, CAI decreased significantly after 6 months of treatment with carvedilol (9.5 +/- 4.9 to 1.3 +/- 2.4, p = 0.03).

CONCLUSIONS

In patients with chronic heart failure, CAI was lower according to the dose of beta-blockers, and no use of beta-blockers was independently associated with CAI. In addition, 6 months of treatment with carvedilol decreased CAI. These results suggest that beta-blocker therapy may dose-dependently suppress CSA in patients with chronic heart failure.

Development of Mucoadhesive Patches for Buccal Administration of Carvedilol

A buccal patch for systemic administration of carvedilol in the oral cavity has been developed using two different mucoadhesive polymers. The formulations were tested for in vitro drug permeation studies, buccal absorption test, in vitro release studies, moisture absorption studies and in vitro bioadhesion studies. The physicochemical interactions between carvedilol and polymers were investigated by Fourier transform infrared (FTIR) Spectroscopy. According to FTIR the drug did not show any evidence of an interaction with the polymers used and was present in an unchanged state. XRD studies reveal that the drug is in crystalline state in the polymer matrix. The results indicate that suitable bioadhesive buccal patches with desired permeability could be prepared. Bioavailability studies in healthy pigs reveal that carvedilol has got good buccal absorption. The bioavailability of carvedilol from buccal patches has increased 2.29 folds when compared to that of oral solution. The formulation AC5 (HPMC E 15) shows 84.85 + 0.089% release and 38.69 + 6.61% permeated through porcine buccal membrane in 4 hr. The basic pharmacokinetic parameters like the C(max), T(max) and AUC(total) were calculated and showed statistically significant difference (P<0.05) when given by buccal route compared to that of oral solution.

Randomized study of early intravenous esmolol versus oral beta-blockers in preventing post-CABG atrial fibrillation in high risk patients identified by signal-averaged ECG: results of a pilot study

BACKGROUND

Patients with prolonged signal-averaged ECG have four times higher risk for development of atrial fibrillation (AF) after coronary artery bypass surgery (CABG). Incidence of AF is reduced, but not eliminated by prophylaxis with beta-blockers. The limitations of prophylaxis with oral beta-blockers may be related to the delayed effect of oral therapy. We performed a pilot study of the efficacy of early intravenous esmolol and an oral beta-blocker regimen for prevention of postoperative AF.

METHODS

Fifty patients referred for CABG and considered to be at high risk for postoperative AF on the basis of prolonged signal-averaged ECG P wave duration > 140 ms were randomized to receive either a 24-hour infusion of esmolol 6-18 hours after CABG, at an average dose 67 +/- 7 microg/kg/min, followed by oral beta-blockers versus oral beta-blockers only beginning on postoperative day 1.

RESULTS

Seven of 27 patients (26%) in the esmolol group and 6 of 23 patients (26%) in the oral beta-blocker group developed postoperative AF, P = NS. The mean time of onset of AF (2.7 +/- 0.5 vs 2.7 +/- 0.3 postoperative day, P = NS) and the median duration of AF (10 [2192] vs 7 [1.16] hours, P = NS) were similar between the two groups. Eleven (41%) patients treated with esmolol developed adverse events (hypotension: 8, bradycardia requiring temporary pacing: 2, left ventricular failure:1 patient) as compared to only one patient (4%) in the beta-blocker group who developed hypotension, P = 0.006.

CONCLUSIONS

This randomized controlled pilot study suggests that intravenous esmolol is less well tolerated and offers no advantages to standard beta-blocker in preventing AF after CABG.

Cardiovascular risk factors in hypertension: rationale and design of studies to investigate the effects of controlled-release carvedilol on regression of left ventricular hypertrophy and lipid profile

Patients at high risk for hypertension may require several therapeutic agents to lower their blood pressure to guideline-recommended targets. Some antihypertensive agents are more effective than others in protecting against cardiovascular morbidity and mortality. Numerous beta-blocking agents have been approved by the US Food and Drug Administration (FDA) for the treatment of hypertension. Previous trials have demonstrated that although all beta-blockers effectively reduce blood pressure, there are differences in how they affect various metabolic factors. In 2 trials, a novel controlled-release (CR) formulation of carvedilol will be tested against other selective beta-blockers to determine whether differences exist in their individual effects on cardiovascular risk factors. These will be the first head-to-head trials using carvedilol CR to determine whether the differing pharmacologic actions among beta-blockers result in varying effects on cardiovascular risk factors.

Serum sickness-like reaction to Pamabrom

Pamabron is a common over-the-counter diuretic used for relief of menstrual-associated symptoms. An urticarial eruption, with systemic complaints consistent with a serum sickness-like reaction, attributed to Pamabron is described. A review of the literature concerning Pamabron and dermatology is discussed.