Authors (including presenting author) :
Fong MK(1), Leung WK(2), Chen J(1), Koo HY(2), Lam TN(3), Chan WY(2), Yick PK(1), Mak CK(2), Mak LK(2)
Affiliation :
(1)Department of Pharmacy, Ruttonjee & Tang Shiu Kin Hospitals, (2)Department of Pharmacy, Tseung Kwan O Hospital, (3)School of Pharmacy, The Chinese University of Hong Kong
Introduction :
Pharmacists are competent and skillful to conduct Therapeutic Drug Monitoring (TDM) to reinforce the safety and efficacy of medication therapy. This expertise is exceptionally applicable to vancomycin due to its narrow therapeutic index. The prescribing pattern of vancomycin from physicians vary widely in daily practice, which might lead to compromised patient outcomes. In addition, AUC-guided monitoring is advocated in the recently revised consensus guideline on therapeutic monitoring of vancomycin.
Objectives :
The objectives of this study are to (1) determine whether enhanced therapeutic vancomycin monitoring service with pre-designated protocol can improve the efficacy and safety of vancomycin therapy than that of current practice, (2) elucidate the correlation between trough-level and AUC in the local population, and hence to evaluate the potential of AUC-guided TDM and (3) investigate whether AUC-guided TDM improves efficacy and safety of vancomycin treatment than that of trough level-guided TDM.
Methodology :
A pre- and post-implementation phase of pharmacist-enhanced vancomycin TDM service with pre-designated protocol was enforced in two local public hospitals. Clinical outcomes of the patients from both groups were compared. Data from both groups were used to validate five population pharmacokinetic models of vancomycin. The best-fitted model was then utilized to estimate the AUC24 value and correlations between AUC24 value and the measuring endpoints were determined.
Result & Outcome :
The post-implementation group demonstrated a significantly higher proportion of patients achieving the target trough level (80.4% vs 69.2%, p = 0.001), as compared to the pre-implementation phase. The time to reach the target therapeutic level was found to be 9 hours earlier in the post-implementation phase (76.8 hours vs 85.8 hours), despite the duration of vancomycin therapy was comparable between the two groups. The incidence of nephrotoxicity was significantly fewer in the post-implementation group (4.8%vs 12.1%, p=0.001). Poor baseline renal function and AUC24>600 were associated with higher risk of nephrotoxicity.
