on the assumption that plasma unbound drug concentrations are therapeutically active , the value of saliva concentrations in predicting plasma unbound theophylline concentrations was investigated in 25 ambulatory adults ( aged 27 to 84 years ) receiving theophylline ( 225-1350 mg aminophylline daily ) for asthma or chronic bronchitis .
C0039771
theophylline
C0004096
asthma