Sustained-release theophylline 10.1 mg/kg b.d. was given with placebo or fenoterol 2.5 mg t.d.s. to 12 patients with chronic airway obstruction.
Fenoterol did not significantly affect the steady-state serum theophylline trough level (11.84 µg/ml for fenoterol vs 11.10 µg/ml for placebo). Addition of fenoterol produced no further increase in spirometric function nor in clinical status.
Key words asthma - theophylline - fenoterol - sustained-release formulation - serum theophylline levels - bronchodilator effects