Monitoring therapy involving drugs exhibiting high intersubject variation and/or narrow therapeutic index has become more generally accepted in hospitals. This paper describes an audit conducted jointly by clinical pharmacists and clinical biochemists into the use and therapeutic value of a drug monitoring service in a general hospital using theophylline as a model. Assay values were categorized as 'subtherapeutic', 'therapeutic' or 'potentially toxic'. The reporting procedures involving the two departments were evaluated along with action taken by the requesting clinicians. The study showed that 60% of the theophylline assay results fell within the therapeutic range at the time of sampling. However only 38% of samples were considered to have been taken under steady state conditions. There was a significant delay in relaying the results to the clinicians. Procedural changes involving sampling times, analytical techniques, recording and conveying results to clinicians and co-operative policies between the departments of pharmacy and clinical chemistry have been implemented as a result of this study.
Adult Aging