The development of a drug measurement service at St. Paul's Hospital: a pharmacy perspective.

Recently, there has been much emphasis on the value of "Therapeutic Drug Monitoring" (TDM). TDM includes clinical attention to the appropriateness, efficacy, side effects and toxicity of drug usage as it relates to the pharmacokinetics of the drug in the patient. The goal of TDM is to optimize drug therapy in each patient through the appropriate choice, dose and monitoring of drug use. The Drug Measurement Service (DMS) at St. Paul's Hospital is a cooperative venture of the departments of medicine, laboratories and pharmacy. The main function of the DMS is TDM. Also, the service educates staff physicians, residents and interns in the proper use and interpretation of serum drug levels. This will make future drug level measurements more beneficial to the patient. This paper outlines the need for a TDM service, the structure and activities of the service, the materials and methods used, and the basic pharmacokinetics and dosing recommendations of the first drug monitored (theophylline). The results of the first six months' experience are presented and discussed.