Compliance of chronic asthmatics with oral administration of theophylline as measured by serum and salivary levels.

A group of ambulatory asthmatic children was studied with serum and salivary theophylline levels following a prescribed dose of a hydroalcoholic solution of theophylline to determine compliance. The gas chromatographic procedure used was both selective and sensitive for theophylline without the necessity of withholding coffee, tea, chocolate, or cocoa. In the first group of patients, only 11% achieved therapeutic levels, 65% had less than therapeutic levels, and 23% had no measurable drug in saliva. With more directive and supervised drug administration in a second group of patients, 42% achieved therapeutic levels, 51% were below therapeutic levels, and only 6% had no measurable drug. Monitoring patients with salivary theophylline levels proved an effective way of improving compliance and also alerted physicians to noncompliance as a possible explanation of "treatment failure". Salivary specimens are readily obtained and noninvasive so that the technique is readily adaptable for use in the office of clinic setting.