Day-night variation of airways status in sympathomimetic- and theophylline-treated asthma patients

Abstract

Eleven diurnally active asthma patients having a history of nocturnal asthma and treated regularly with albuterol or metaproterenol alone or with twice-daily sustained-release theophylline were evaluated for day-night pattern in peak expiratory flow (PEF) and use of supplemental β-agonist aerosol for relief of acute asthma. Overall, significant day-night variation was observed in the supplemental use of β-agonist medication and in airway patency. The patients managed by albuterol or metaproterenol alone used supplemental β-agonist medication significantly more between 4 AM and 8 AM and also 8 PM and midnight in comparison to 4 PM to 8 PM; this was not true for those treated with both theophylline and β-agonist aerosol. In patients taking a β-agonist bronchodilator, the 24-hour mean PEF was greater than in those who also took theophylline, but the day-night variation in PEF was comparable. Supplemental isoproterenol use was significantly correlated with circadian amplitude of the PEF rhythm, but not with the 24-hour mean PEF. The greater the day-night variation in PEF, the greater the reliance on a supplemental β-agonist bronchodilator.