Clearance of lung secretions in patients with chronic bronchitis: effect of terbutaline and ipratropium bromide aerosols.
A placebo controlled, double-blind, cross-over study was carried out to examine both the bronchodilator properties and the effect on lung mucociliary clearance of terbutaline (Bricanyl), a beta agonist, and ipratropium (Atrovent), a synthetic anticholinergic drug. Both were given regularly (two puffs four times a day for 1 week) from pressurised metered dose inhalers to patients with chronic obstructive bronchitis. A total of 10 patients completed the terbutaline study and 12 patients the ipratropium study; of these, seven patients were common to both studies. Measurements of the pulmonary function indices, forced expiratory volume in 1 s, forced vital capacity (FVC), peak expiratory flow rate and the flow rate at 50% of FVC measured from maximal expiratory flow-volume curves, confirmed the bronchodilator action of both drugs in these patients. Clearance of lung secretions was measured by the non-invasive, radioaerosol technique. No evidence was found that either drug had any effect on the rate of mucociliary clearance. The radioaerosol tracer particles used for measuring lung clearance, although inhaled under strictly controlled conditions, were deposited significantly more towards the lung periphery after treatment with ipratropium only. This suggested that ipratropium reduced the resistance to the entry of inhaled aerosols in the small airways.
D000336:Aerosols; D000368:Aged; D001286:Atropine Derivatives / Q000627:therapeutic use*; D001991:Bronchitis / Q000188:drug therapy* / Q000503:physiopathology; D002908:Chronic Disease; D002923:Cilia / Q000187:drug effects; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D006801:Humans; D009241:Ipratropium / Q000627:therapeutic use*; D008875:Middle Aged; D009092:Mucous Membrane / Q000187:drug effects; D012123:Pulmonary Ventilation; D012129:Respiratory Function Tests; D013726:Terbutaline / Q000627:therapeutic use*
D000336:Aerosols; D001286:Atropine Derivatives; D009241:Ipratropium; D013726:Terbutaline