Background Therapeutic drug monitoring (TDM) is currently planned and ordered by doctors at an outer metropolitan hospital. Previous audits looking at clozapine and low-molecular weight heparin (LMWH) TDM found that sample timing was poor in relation to steady state and peak/trough concentrations (Clozapine (n=196) 41% samples were not troughs, and LMWH (n=193) 57% samples were not at peak levels).

A literature review has shown that there is small and sporadic research within this area. The research has shown some benefits of a pharmacist-led TDM service. Unfortunately, the studies within the literature are often limited by a small sample size and factors such as a specific population (i.e. oncology patients) or specific pharmacists (i.e. the infectious diseases pharmacist).

Purpose To review the TDM process within an outer metropolitan hospital.

Material and methods A retrospective audit was conducted on TDM undertaken between 1 January and 31 December 2016. Patients were identified using the electronic pathology database. Patients were excluded if under the age of 18, in an outpatient setting or the emergency department. Progress notes, medication charts and other relevant pathology were reviewed via the electronic pathology program and via the Electronic Clinical Record Management System. They were assessed for appropriateness of the timing of collection, compliance to recommended TDM guidelines, the appropriateness of action of the resulting pathology and the documented involvement of the pharmacist.

Results Atotal of 3095 tests were included in the study, covering 11 medications. Of these, 32.6% were collected at an inappropriate time, making interpretation difficult and at a pathology cost of $23,084.86. On average, 50% of the doses administered to patients after TDM were appropriate based on results and the clinical scenario. There was documented pharmacist advice on the TDM result in only 8.6% of the time.

Conclusion TDM has a large impact on the therapy and outcome of patients. This audit showed that TDM is currently performed sub-optimally and with an unknown or ad hoc role of the pharmacist. These preliminary results show a review of the current TDM process is required and, with their drug and pharmacokinetic knowledge, a greater impact and role of the pharmacist is required.

References and/or acknowledgements Nil.

No conflict of interest.