Chronopharmacology of Albuterol in Hospitalized Asthmatic Children

Eleven children (8–16 years old) hospitalized for acute bronchospasm were included in this investigation. Throughout the study, the children received the standardized course of therapy for hospitalized asthmatics with corticosteroids and albuterol nebulizations. Children receiving ipratropium were excluded from the study. Spirometric measurements, including forced expiratory volume in 1s (FEV₁), were made immediately before and 30 min after each albuterol nebuliza-tion over a 24-h period. The well-known temporal changes in FEV₁, were observed in patients suffering from nocturnal asthma (NA): basal values were maximal at midday (10 a.m. to 2 p.m.) and lowest in the evening or at night (10 p.m. to 6 a.m.). This 24-h variation in lung function was not found in children without nocturnal exacerbations of their asthma. A 24-h variation was also observed in albuterol-induced bronchodilation in patients with NA: maximal effectiveness occurred at night, and lower effect was obtained with the midday administration. The albuterol-induced increases in FEV₁, were not clinically significant in children without nocturnal asthma except when the β₂-agonist was inhaled between 10 p.m. and 2 a.m. The data suggest that patients with nonnocturnal asthma might have different drug requirements than those with nocturnal symptoms. Key Words: Albuterol—Asthma—Circadian rhythms—-Children—FEV₁.