[Usefulness of "Biotrack Theophylline kit" for measuring serum theophylline concentration in patients with chronic asthma].

Patients with chronic asthma are often treated with sustained-release theophylline preparations. Clearance of theophylline is variable between individuals and grossly dependent on the age of the patient. It is important to measure the theophylline concentration in serum before giving a bolus shot of intravenous aminophylline for the patients taking oral theophylline. "Biotrack Theophylline kit" is a device to detect serum theophylline levels, applying whole blood and using the method of latex agglutination inhibition. It is as accurate as HPLC (high performance liquid chromatography), which is the standard method for measuring serum theophylline levels. Good correlation between the two methods was achieved (r = 0.973, in N = 108). We measured serum theophylline levels using this kit in ten patients who were on round-the-clock treatment but developed acute asthma attacks. The usefulness of this device was shown because of its accuracy and the rapid and easy maneuver.