Action of tulobuterol and fenoterol on the mucociliary clearance

The influence of tulobuterol and fenoterol upon mucociliary clearance (mC) and airway obstruction was investigated in 8 patients with chronic obstructive bronchitis and two patients with chronic bronchial asthma. The lung function and mC measurements were repeated after a 1-week random oral treatment with 4 mg tulobuterol/day or 7.5 mg fenoterol/day in a double-blind cross-over design. Tulobuterol and fenoterol improved mC of the total, central and peripheral bronchial tree significantly in comparison to the pretreatment values (p less than 0.001) reaching, after beta 2-agonist therapy, values observed in normal subjects. In comparison to no treatment and pretreatment with oral fenoterol, tulobuterol protected slightly better from the inhalative provocation with 99mTc radioactive erythrocytes used to measure mC. Inhalative fenoterol was more efficient than oral fenoterol or tulobuterol to reverse the bronchospastic part of airway obstruction. No differences of mean daily peak flows, systolic and diastolic systemic blood pressure measurements and pulse rate were recorded during tulobuterol and fenoterol treatment. Both drugs were tolerated without side effects.