Investigation of the actual conditions and attitude surveillance of physicians to ward therapeutic drug monitoring (TDM) of theophylline were performed in outpatients prescribed a control released theophylline-tablet (Theodur ®) in November 1996. TDM of theophylline was performed in 1.6% of patients to whom were prescribed Theodur® during this period. The ratio of the patients who had a TDM history of theophylline was 28.1% of all patients prescribed Theodur®, while it was 41.7% in patients receiving over the usual Theodur® dose range (400 mg/day). Most physicians recognized the benefit of TDM, while about a half considered that TDM of theophylline is not essential for patients taking more than 400mg/day of the drug when their clinical condition is stable.
