The effectiveness of drug level monitoring and pharmacokinetics in individualizing theophylline therapy.

A pharmacokinetic method for individualizing theophylline dosage is described. The method was shown to be reliable and accurate, and maintained significantly more patients within the optimum therapeutic range when compared with conventional regimens. The study also showed that when conventional dosage regimens are used, a large proportion of patients exhibit theophylline levels well below the optimum therapeutic range. Population pharmacokinetic data for theophylline and the effect of congestive heart failure on its clearance are also presented.