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Beta Agonists (beta + agonist)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

Inotropes in the beta-blocker era

CLINICAL CARDIOLOGY, Issue S3 2000
B. D. Lowes M.D.
Abstract Beta-adrenergic blocking agents are now standard treatment for mild to moderate chronic heart failure (CHF). However, although many subjects improve on beta blockade, others do not, and some may even deteriorate. Even when subjects improve on beta blockade, they may subsequently decompensate and need acute treatment with a positive inotropic agent. In the presence of full beta blockade, a beta agonist such as dobutamine may have to be administered at very high (> 10 ,g/kg/min) doses to increase cardiac output, and these doses may increase afterload. In contrast, phosphodiesterase inhibitors (PDEIs) such as milrinone or enoximone retain their full hemodynamic effects in the face of beta blockade. This is because the site of PDEI action is beyond the beta-adrenergic receptor, and because beta blockade reverses receptor pathway desensitization changes, which are detrimental to PDEI response. Moreover, when the combination of a PDEI and a beta-blocking agent is administered long term in CHF, their respective efficacies are additive and their adverse effects subtractive. The PDEI is administered first to increase the tolerability of beta-blocker initiation by counteracting the myocardial depressant effect of adrenergic withdrawal. With this combination, the signature effects of beta blockade (a substantial decrease in heart rate and an increase in left ventricular ejection fraction) are observed, the hemodynamic support conferred by the PDEI appears to be sustained, and clinical results are promising. However, large-scale placebo-controlled studies with PDEIs and beta blockers are needed to confirm these results. [source]

Asthma Pharmacotherapy Prescribing in the Ambulatory Population of the United States: Evidence of Nonadherence to National Guidelines and Implications for Elderly People

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 7 2008
Prakash Navaratnam MPH
OBJECTIVES: To examine the level of physician adherence to the Expert Panel Report 2 (EPR-2) pharmacotherapy guidelines of the asthma population, specifically in the elderly ambulatory patient population of the United States. DESIGN: Retrospective cross-sectional study using a national survey. SETTING: National Ambulatory Medical Care Survey data of U.S. elderly patients from 1998 through 2004. PARTICIPANTS: The weighted population sample size was 82,020,318 patients. There were 1,540 observations in this study (preweighted sample size) and 96 strata, with 446 population sampling units (PSUs). There were 11,868,340 patients that were elderly, and they accounted for 14.5% of the overall population sampled. MEASUREMENTS: Specific patient demographic variables, physician demographic variables, and information about asthma medications prescribed were extracted from the data set and analyzed. Descriptive statistics for the patient demographic, physician demographic, and asthma pharmacotherapy variables were generated. A series of logistic regression models were created, with the choice of asthma pharmacotherapy agent used as the dependent variable and patient and physician demographic variables as the independent variables. RESULTS: A major finding was that physicians were not adherent to the National Asthma Education and Prevention Program EPR-2 asthma pharmacotherapy guidelines. Another finding was that, although elderly patients (aged ,65) were exposed to more-stable patterns of care, they were less likely to be prescribed controller medications, long-acting bronchodilators (LABAs), combinations of inhaled corticosteroids and LABAs, and short-acting beta agonists than patients aged 35 to 64. CONCLUSION: A more-concerted effort needs to be undertaken to improve physician adherence to the EPR-2 guidelines, especially in prescribing asthma pharmacotherapy to elderly patients. [source]

Unmet need in inadequately controlled asthma

RESPIROLOGY, Issue 2007
Richard BEASLEY
Abstract: Over the last 20 years in Australia, outcomes have improved for patients with asthma. With the advent of inhaled corticosteroids and long-acting beta agonists, and improvements in management including implementation of the guided self-management plan system of care, the mortality rate for asthma has fallen by almost half. However, despite huge improvements, there remains a small but significant cohort of patients with inadequately controlled severe persistent asthma. This group of patients consumes a substantial proportion of public health resources. Patients who have poorly controlled asthma, despite receiving ,optimal' treatment, are the ones most likely to benefit from new therapies such as those that target IgE. This presentation provides an overview of severe asthma in terms of prevalence and morbidity, mortality, economic costs and then considers a way forward in terms of identifying patients in greatest need of novel treatment such as omalizumab. [source]

Lessons for management of anaphylaxis from a study of fatal reactions

CLINICAL & EXPERIMENTAL ALLERGY, Issue 8 2000
Pumphrey
Background The unpredictability of anaphylactic reactions and the need for immediate, often improvised treatment will make controlled trials impracticable; other means must therefore be used to determine optimal management. Objectives This study aimed to investigate the circumstances leading to fatal anaphylaxis. Methods A register was established including all fatal anaphylactic reactions in the UK since 1992 that could be traced from the certified cause of death. Data obtained from other sources suggested that deaths certified as due to anaphylaxis underestimate the true incidence. Details of the previous medical history, the reaction and necropsy were sought for all cases. Results Approximately half the 20 fatal reactions recorded each year in the UK were iatrogenic, and a quarter each due to food or insect venom. All fatal reactions thought to have been due to food caused difficulty breathing that in 86% led to respiratory arrest; shock was more common in iatrogenic and venom reactions. The median time to respiratory or cardiac arrest was 30 min for foods, 15 min for venom and 5 min for iatrogenic reactions. Twenty-eight per cent of fatal cases were resuscitated but died 3 h,30 days later, mostly from hypoxic brain damage. Adrenaline (epinephrine) was used in treatment of 62% of fatal reactions but before arrest in only 14%. Conclusions Immediate recognition of anaphylaxis, early use of adrenaline, inhaled beta agonists and other measures are crucial for successful treatment. Nevertheless, a few reactions will be fatal whatever treatment is given; optimal management of anaphylaxis is therefore avoidance of the cause whenever this is possible. Predictable cross-reactivity between the cause of the fatal reaction and that of previous reactions had been overlooked. Adrenaline overdose caused at least three deaths and must be avoided. Kit for self-treatment had proved unhelpful for a variety of reasons; its success depends on selection of appropriate medication, ease of use and good training. [source]