Abstract Rationale Salbutamol is the traditional agent used in bronchodilator testing; however, responses to salbutamol are heterogeneous and may even be paradoxical (worsening lung function). The use of ipratropium for this purpose is far less well characterized. On the other hand, the benefit of adding a second bronchodilator once a full response to the first has been achieved remains uncertain. Methods Healthy subjects and patients with asthma attended two visits during which they received sequential inhalation of salbutamol followed by ipratropium, or ipratropium followed by salbutamol. The sequence administered during the first visit was determined by randomization. Agents were delivered via spacer (salbutamol 400 µg; ipratropium 80 µg). Airway mechanics were assessed by impulse oscillometry (R5, R20, R5-R20, X5, Fres, AX) performed before and after the agent’s expected peak effect (∼15 min for salbutamol; ∼20 min for ipratropium). Oscillometric variables were expressed as z-score according to reference equations (Gochicoa-Rangel et al. ), and changes were evaluated through repeated-measures ANOVA and paired t-tests with Bonferroni correction. Results Seventy participants were included (37 healthy, 33 with asthma; mean age 36. 1 years range 8. 2-81. 8; 24 male). Baseline oscillometry results were similar at both visits, indicating no carryover effect. Patients with asthma exhibited more abnormal baselines lung function and showed greater responses to bronchodilators than healthy subjects. Compared with salbutamol, ipratropium as the first agent tended to produce larger and more consistent improvements in most oscillometric parameters, particularly among asthma patients Fig. 1. Specifically, salbutamol improved R5, X5 and AX in healthy subjects and nearly all variables in asthma patients, while ipratropium improved almost all oscillometric variables in both groups. After the first agent reached its peak effect, the second agent produced only modest additional changes. Paradoxical responses were observed with both agents, but they were largely independent, i. e. , most individuals who exhibited a paradoxical response to one agent showed a favorable response to the other. Conclusions Ipratropium tended to produce more consistent and greater improvements in lung function than salbutamol, suggesting that it might be postulated as the agent of choice for bronchodilator testing, or even for the treatment of acute asthma exacerbations. In patients who do not respond to salbutamol, evaluating their responsiveness to ipratropium should be considered, and vice versa. Finally, our findings do not support the use of a combination of these two bronchodilators. (Results can be consulted in: https: //tesiunamdocumentos. dgb. unam. mx/ptd2025/abrⱼun/0868676/Index. html) This abstract is funded by: None
Alvarado et al. (Fri,) studied this question.
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