Plasma level and broncholytic effect of choline theophyllinate after a single dose of a press-coated tablet formulation.

The broncholytic effect and plasma concentrations of theophylline in 10 asthmatic patients were studied for 8 hours after a single dose of 600 mg choline theophyllinate in press-coated 200 mg tablets. Therapeutic concentrations of theophylline were rapidly achieved and the plasma peak averaged 10.4 mug/ml after 2 hours. The broncholytic effect was closely related to the plasma level of theophylline. The largest change was in FEV1, which was significantly increased 1 to 6 hours after the dose. No patient complained of adverse effects. A theophylline concentration of 7 mug/ml plasma was adequate for a broncholytic effect, but a higher level was required for a maximal response. The results provide a basis for further studies to establish a dosage schedule suitable for prolonged therapy.