Relationship between respiratory symptoms and medical treatment in exacerbations of COPD

Exacerbations of chronic obstructive pulmonary disease (COPD) can be defined symptomatically or by healthcare contacts, yet the relationship between these events is unknown. Data were collected during a 1-yr study of the budesonide/formoterol combination in COPD patients, where exacerbations, defined by increases in treatment, were compared with daily records of respiratory symptoms, rescue medication use and peak expiratory flow (PEF). The relationship between changes in these variables and the medical event was examined using different modelling approaches. Data from the first exacerbation treated with oral corticosteroids and/or antibiotics and/or hospitalisation (event based) were available in 468 patients. Patients exacerbating were significantly more breathless and more likely to report cough than healthy patients, but did not differ in baseline spirometry. Exacerbations defined by changes in individual symptoms were only weakly related to event-based exacerbations; however, defined with 63% of such events being predicted from symptom changes. Changes in rescue medication use or PEF were poor predictors of event-based exacerbations. The mean peak change in symptoms was closely related to the onset of therapy. In conclusion, event-based exacerbations are a valid way of identifying acute symptom change in a chronic obstructive pulmonary disease population. However, daily symptom monitoring is too variable using the current diary cards to make individual management decisions.

Efficacy of cumulative doses of salbutamol administered via Turbuhaler or Diskhaler in patients with reversible airway obstruction

The study aimed to estimate the relative dose potency of salbutamol inhaled via Turbuhaler and Diskhaler. The 24 adult patients participating had chronic reversible airway obstruction. The study was of a double-blind, double-dummy, crossover, randomized design. Five doses of salbutamol Turbuhaler, 50, 50, 100, 200, and 400 microg, were given on one study day at intervals of 30 min. On another study day, five doses of salbutamol Diskhaler, 200, 200, 400, 800, and 1600 microg, were given with the same interval. The treatment days were separated by a washout period of at least 24 h. The inhalation technique was standardized and supervised. Efficacy variables were recorded before and after each study dose. The primary efficacy variable was forced expiratory volume in 1 s (FEV1). When parallel and linear cumulative dose-response curves were statistically compared on a logarithmic scale, the dose potency of salbutamol Turbuhaler vs salbutamol Diskhaler was 1.99 (95% confidence interval 1.52-2.54). This study indicates that only half the dose of salbutamol is required via Turbuhaler as via Diskhaler for the same bronchodilating effect.

Differences in bronchodilating potency of salbutamol in Turbuhaler as compared with a pressurized metered-dose inhaler formulation in patients with reversible airway obstruction

Two studies are presented, with the aim of establishing the dose potency ratio for salbutamol given via Turbuhaler and via a pressurized metered-dose inhaler (pMDI). Both studies were of a double-blind, randomized design. Outpatients with mild-to-moderate chronic reversible airway obstruction were given single doses of salbutamol administered via Turbuhaler and via pMDI. Efficacy and safety variables were measured before and during 6 h after each dose. The first study was a four-way crossover study including 12 patients. The salbutamol doses given were: 50, 100 and 2x100 microg via Turbuhaler and 2x100 microg via pMDI (Ventolin). The study showed that 2x100 microg of salbutamol inhaled via Turbuhaler is more potent than 2x100 microg salbutamol inhaled via a pMDI, and that 100 microg salbutamol via Turbuhaler is at least as potent as 2x100 microg salbutamol inhaled via a pMDI. The second study including 50 patients was a placebo-controlled five-way crossover, study. Two doses of salbutamol via Turbuhaler, 50 and 2x100 microg, and via pMDI, 100 and 2x200 microg, were given. There was a dose-dependent response in forced expiratory volume in one second (FEV1) for both inhalers. Adjusted for differences in baseline FEV1 values, the estimated relative dose potency for Turbuhaler versus pMDI was 1.98:1 (95% confidence interval 12-3.2). These studies showed that the same bronchodilating effect can be achieved when half the dose of salbutamol given via a conventional pressurized metered-dose inhaler is given via Turbuhaler.

Comparison of dose-response effects of inhaled beclomethasone dipropionate and budesonide in the management of asthma

The dose-response effects of inhaled beclomethasone dipropionate (BDP) and budesonide (BUD) administered b.i.d. with the aid of metered dose aerosols were studied in 128 patients (67 men and 61 women, mean age 53 years) suffering from asthma bronchiale. The study was designed as a multi-centre, double-blind, four-period cross-over study, followed by a single-blind double placebo period. BDP was administered in doses of 400 and 1000 micrograms, and BUD in doses of 400 and 800 micrograms. The results in terms of peak expiratory flow (PEF) in the morning and evening, daily symptoms score and use of inhaled beta 2-agonists did not reveal any clinically significant differences between the drugs or between high (800 micrograms BUD, 1000 micrograms BDP) and low (400 micrograms BUD/BDP) doses. However, statistically significant differences were recorded for the corresponding parameters when comparing the placebo with preceding steroid periods. Adverse effects consisting mainly of oropharyngeal candidiasis, hoarseness and cough occurred in 54 of 468 treatment months (12%). The carry-over effects of inhaled steroids are longer lasting than was previously assumed.

Acute asthma--plasma levels and effect of terbutaline i.v. injection

The effects of two different doses (4 and 8 micrograms/kg) of terbutaline i.v. injection were recorded in 64 episodes of acute asthma (heart rate greater than 100 beats/min, peak expiratory flow (PEF) less than 50% of the predicted normal value). Both doses of terbutaline i.v. injections induced a significant increase in PEF and a decrease in pulse rate and systolic blood pressure. No large significant differences were noted between the doses, but palpitations were more pronounced after the higher dose. The results suggest that intravenous administration of 4 micrograms/kg terbutaline is a safe and effective treatment of acute asthma.