title: Day-night patterns in bronchial patency and dyspnea: basis for once-daily and unequally divided twice-daily theophylline dosing schedules.
abstract: Asthma typically worsens overnight. Although 24-hr variation in environmental conditions may contribute to the worsening of dyspnea at night, this does not fully explain day-night patterns of this disease. Circadian (about 24-hr) rhythms in bioprocesses which influence airways patency constitute major contributory factors. The nighttime exacerbation of asthma may represent the influence of circadian bioperiodicities in bronchial patency, airways hyperreactivity to acetylcholine, histamine and house dust, and altered levels of several plasma constituents such as cortisol, epinephrine, histamine and cyclic AMP.
authors.affiliation: School of Public Health, University of Texas, Houston 77225.
authors.forename: M H
authors.initials: MH
authors.lastname: Smolensky
authors.forename: G E
authors.initials: GE
authors.lastname: D'Alonzo
authors.forename: G
authors.initials: G
authors.lastname: Kunkel
authors.forename: P J
authors.initials: PJ
authors.lastname: Barnes
mesh_terms: D001249:Asthma / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D001980:Bronchi / Q000503:physiopathology; D002940:Circadian Rhythm; D004334:Drug Administration Schedule; D004417:Dyspnea / Q000503:physiopathology; D006801:Humans; D013806:Theophylline / Q000008:administration & dosage*
chemical_list: D013806:Theophylline