Failure of ipratropium bromide to modify the diurnal variation of asthma in asthmatic children.

Thirty one children with asthma were given 40 micrograms of ipratropium bromide and identical placebo by inhalation three times a day in a double blind, randomised crossover study to test the ability of an anticholinergic drug to modify the diurnal variation in airway calibre and bronchial reactivity. Subjects measured peak expiratory flow rate approximately eight hourly, before and after inhaled salbutamol, for four week periods. Paired t tests and cosinor analysis were used to assess the diurnal variation in airway calibre from the peak expiratory flow rate recorded before salbutamol and to assess the diurnal variation in bronchodilator responsiveness from the increase in peak expiratory flow rate after salbutamol. Maintenance treatment with ipratropium bromide 40 micrograms three times daily reduced the provocative dose of histamine which caused a 20% fall in FEV1 (geometric mean PD20 = 0.78 v 0.49 mg/ml, p less than 0.05), despite an eight to 12 hour gap between the last dose of ipratropium and histamine challenge. It did not, however, diminish the diurnal variation in airway calibre (mean amplitude = 12.7 v 10.1) or in bronchodilator responsiveness (mean amplitude = 62.4 v 63.5). There was no improvement in the clinical state of subjects while they were taking ipratropium bromide

Erratum: Effect of Polymorphism of the β₂-Adrenergic Receptor on Response to Regular Use of Albuterol in Asthma

<i>Background:</i> Regular use of inhaled β-adrenergic agonists may have adverse effects in some asthma patients. Polymorphisms of the β₂-adrenergic receptor (β₂-AR) can affect its regulation; however, results of smaller studies of the effects of such polymorphisms on response to β-agonist therapy have been inconsistent. <i>Methods:</i> We examined the possible effects of polymorphisms at codons 16 (β₂-AR-16) and 27 (β₂-AR-27) on response to albuterol by genotyping 190 asthmatics who had participated in a trial of regular versus as-needed albuterol use. <i>Results:</i> During the 16-week treatment period, patients homozygous for arginine (Arg/Arg) at β₂-AR-16 who used albuterol regularly had a small decline in morning peak expiratory flow (AM PEF). This effect was magnified during a 4-week run-out period, when all patients returned to as-needed albuterol only. By the end of the study, Arg/Arg subjects who had used albuterol regularly had an AM PEF 30.5 ± 12.1 liters/min lower (p = 0.012) than Arg/Arg patients who had used albuterol as needed only. Subjects homozygous for glycine at β₂-AR-16 showed no such decline. Evening PEF also declined in the Arg/Arg regular but not in as-need albuterol users. No significant differences between regular and as-needed treatment were associated with polymorphisms at β₂-AR-27. <i>Conclusions:</i> Polymorphisms of the β₂-AR may influence airway responses to regular inhaled β-agonist treatment

A new perspective on concepts of asthma severity and control

Concepts of asthma severity and control are important in the evaluation of patients and their response to treatment but the terminology is not standardised and the terms are often used interchangeably. This review, arising from the work of an American Thoracic Society/European Respiratory Society Task Force, identifies the need for separate concepts of control and severity, describes their evolution in asthma guidelines and provides a framework for understanding the relationship between current concepts of asthma phenotype, severity and control. "Asthma control" refers to the extent to which the manifestations of asthma have been reduced or removed by treatment. Its assessment should incorporate the dual components of current clinical control (e.g. symptoms, reliever use and lung function) and future risk (e.g. exacerbations and lung function decline). The most clinically useful concept of asthma severity is based on the intensity of treatment required to achieve good asthma control, i.e. severity is assessed during treatment. Severe asthma is defined as the requirement for (not necessarily just prescription or use of) high-intensity treatment. Asthma severity may be influenced by the underlying disease activity and by the patient's phenotype, both of which may be further described using pathological and physiological markers. These markers can also act as surrogate measures for future risk. Copyrigh