Abstracts

Abstract

Bronchodilatation and Bronchoprotection in Asthmatic Preschool Children from Formoterol Administered by Mechanically Actuated Dry-Powder Inhaler and Spacer; Nielsen, K.G., Bisgaard, H.; Am. J. Resp. Crit. Care Med. 2001, 164, 256–259.Background. Young asthmatic children have a specific need for more prolonged duration of bronchodilatation and bronchoprotection than is provided by intermittent therapy with short-acting beta-agonists. This is particularly true since young children are often under the care of others for large parts of the day. Inhaled Formoterol has a rapid onset of action, within a few minutes after inhalation, maximum effect at 30 minutes and sustained bronchodilatation and bronchoprotection for over 12 hours.Objective. The objective was to evaluate the bronchodilatory and bronchoprotective efficacy of long-acting beta-agonist Formoterol, delivered as a dry-powder from a mechanically actuated dry-powder inhaler with a spacer.Clinical Population. The clinical population included 12 asthmatic children, ages 2 to 5 years.Clinical Protocol. Lung function was evaluated using specific airway conductance in a whole body plethysmograph. Cold dry air challenge with hyperventilation was used as a bronchial challenge, and the responsiveness was estimated as a change in the specific airway resistance. Bronchoprotective effect of Formoterol Turbohaler 9 mcg was compared with Salbutamol 200 mcg and placebo at 15 minutes, 4 hours, and 8 hours post dose in a randomized, double-blind, placebo-controlled crossover study. All treatments were delivered from a DPI “Turbohaler” actuated mechanically into a spacer.Clinical Findings. Formoterol and Salbutamol produced similar and significant bronchodilatation at the first measurement, at 3 minutes post dose. Formoterol, however, offered persistent and stable bronchodilatation for at least 8 hours, while Salbutamol produced significant bronchodilatation for less than 4 hours. Formoterol produced significant bronchoprotection of 80% for at least 8 hours. The bronchoprotection from Salbutamol lasted less than 4 hours.Conclusions. The conclusions of the authors were that Formoterol administered via dry-powder inhaler with a spacer in a single dose produced rapid (approximately 3 to 5 minutes onset) and sustained bronchodilatation (up to 12 hours) and clinically significant bronchoprotection for at least 8 hours in 2- to 5-year-old asthmatic children. This investigation further suggests that using a spacer is an effective way to deliver aerosol in young asthmatic children.Reviewer's Comments. While Formoterol is exciting in terms of its pharmacodynamic properties, its delivery system is less than optimal when compared with ease of use of a Salmeterol discus haler. The introduction of a spacer here adds further mechanica1 obstacles, particularly for young children who are 2 to 5 years of age. However, the pharmacokinetic properties, i.e., the bronchoprotection and the bronchodilatation lasting up to 12 hours, is a useful modality when considering young children who are often in day care or nursery school for a large proportion of the day.Christopher Randolph, M.D. Waterbury, CT